Pointwise_TutorialWorkbook

PointwiseTutorial Workbook

Copyright © 2011 Pointwise, Inc.

All rights reserved.

Pointwise, Inc. reserves the right to make changes in specifications and other information contained in this document without prior notice.

ALTHOUGH DUE CARE HAS BEEN TAKEN TO PRESENT ACCURATE INFORMATION, POINTWISE, INC. DISCLAIMS ALL WARRANTIES WITH RESPECT TO THE CONTENTS OF THIS DOCUMENT (INLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE), EITHER EXPRESSED OR IMPLIED. POINTWISE, INC. SHALL NOT BE LIABLE FOR DAMAGES RESULTING FROM ANY ERROR CONTAINED HEREIN, INCLUDING, BUT NOT LIMITED TO, FOR ANY SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF, OR IN CONNECTION WITH, THE USE OF THIS DOCUMENT.

Pointwise, Inc.213 S. Jennings Ave.Fort Worth, Texas 76104-1107, USA

Phone: (817) 377-2807Toll free: (800) 4PTWISEFax: (817) 377-2799

Email: [email protected]: http://www.pointwise.com

Notice: The terms of the agreement under which you are acquiring the right to use the software include the “Right to Use License” attached hereto or accompanying the software. Your purchase, license, receipt or use of the software constitutes your acceptance of all the “Right to Use License.”

Pointwise, Gridgen, and Get the Point are registered trademarks and GridgenGlyph and PointwiseGlyph are trademarks of Pointwise, Inc.

Pointwise® uses the Qt® toolkit from Qt Software, a subsidiary of Nokia Corporation. Nokia, the Nokia logo, Qt®, and the Qt logo are trademarks of Nokia Corporation and/or its subsidiaries in Finland and other countries. FLEXnet is a registered trademark of Acresso Software in the United States and/or other countries. Pointwise® uses HDF5 from the HDF Group. Pointwise® uses Thread Building Blocks (TBB) from Intel Corp., licensed under the Gnu Public License V2 with the runtime exception. Intel® is a registered trademark of Intel Corporation in the United States, other countries, or both. Pointwise® uses the TetMesh-GHS3D tetrahedral mesher, Copyright © DISTENE S.A.S./INRIA.

FIELDVIEW and FVX are trademarks of Intelligent Light. FIELDVIEW Unstructured format Copyright © 1996-2009 Intelligent Light. Used by Permission. FIELDVIEW Unstructured format is intended for the exclusive use of the licensers of FIELDVIEW from Intelligent Light. PATRAN is a registered trademark of The MSC.Software Corporation. NASTRAN is a registered trademark of NASA. ANSYS FLUENT is a trademark of ANSYS. Star-CD is a trademark of CD-adapco. ANSYS CFX is a registered trademark of ANSYS. OPENFOAM® is a registered trademark of OpenCFD Limited.

OpenGL® and the oval logo are trademarks or registered trademarks of Silicon Graphics, Inc. in the United States and/or other countries worldwide. LINUX is a trademark of Linux Torvalds. REDHAT is a registered trademark of Red Hat,Inc. Microsoft and Windows are registered trademarks of Microsoft Corp. UNIX and XWindow System are registered trademarks in the U.S. and other countries, licensed exclusively through the X/Open Company Limited. Mac and Mac OS are registered trademarks of Apple Computer, Inc. All other registered and unregistered trademarks are properties of their respective owner.

1. DEFINITIONS.

(a) “Licensed Software” means any computer

program(s) supplied by Pointwise, Inc. (PWI) to

Licensee under a valid Purchase Order or Con-

tract, whether in object code, reconfigurable

binary, or any other form; video media and

training aids; and any backup or other copies,

updates, derivative works, modifications,

enhancements, and extensions thereof.

(b) “Documentation” means user manuals,

documentation binders, release notes, installa-

tion notes, written utility programs and other

written or graphic materials related to the

Licensed Software and all copies thereof.

(c) “Licensed Product(s)” means the Licensed

Software and Documentation.

(d) “Maintenance Period” means the first cal-

endar year of a perpetual license or 12 months

for an annual license.

2. LICENSE.

PWI grants to Licensee a non-exclusive, non-

transferable license to use the Licensed Prod-

ucts in accordance with the terms and condi-

tions set forth herein. As long as this License is

in effect, Licensee may transfer its use of the

Licensed Products to a replacement computer

system on a temporary or permanent basis,

provided that Licensee gives PWI written

notice of such transfer.

3. TERM and FEES.

The Term of the Right to Use License is annual

or perpetual, as set forth in the Purchase

Order or Contract, provided that the License

has not been terminated as set forth in Sec-

tion 10.

All applicable fees are payable to PWI within

thirty (30) days from Invoice Date. Failure to

pay such fees in a timely manner is a material

breach of this License. Licensee agrees to pay

any legal or collection fees incurred by PWI in

collecting any amounts that may be delin-

quent.

4. COPIES and MODIFICATIONS.

Licensee may copy the Licensed Products in

whole or in part, in written or machine read-

able form for use in understanding the

Licensed Software and for archive or backup

purposes. Licensee shall reproduce and

include PWI’s trade secret or copyright notices

on and in any copies, in any form. Licensee

shall not reverse assemble, reverse compile or

otherwise reverse engineer the Licensed Soft-

ware in whole or in part.

The License includes the right to reproduce

the Licensed Software’s documentation exclu-

sively for the use of Licensee and its employ-

ees only. All other reproduction and

distribution is strictly prohibited.

5. OWNERSHIP.

All Licensed Products and the information they

contain, any updates and all copies of them

are PWI’s or PWI’s licensors’ property, and title

to them remains in PWI or such licensors. All

applicable rights in patents, copyrights or

trade secrets in the Licensed Products are and

will remain in PWI and PWI’s licensors. No title

to or ownership of the Licensed Software or

the information they contain is transferred to

Licensee. Licensee agrees that any terms and

conditions imposed by PWI’s licensor and

communicated by PWI to Licensee by PWI,

shall apply to the Licensed Products.

6. CONFIDENTIALITY.

(a) Licensee will take all reasonable precau-

tions to maintain the confidentiality of the

Licensed Products, and agrees to take all rea-

sonable and necessary steps to protect the

patents, trademarks, copyrights, trade secrets

and any other forms of intellectual or indus-

trial property of PWI in the Licensed Products.

(b) Licensee will not provide the Licensed

Products to any person, other than employees

of Licensee, without PWI’s prior written con-

sent, except during the period any such per-

son is on Licensee’s premises with Licensee’s

permission for purposes specifically related to

Licensee’s use of the Licensed Products.

7. COPYRIGHT AND PATENT INDEMNITY.

PWI assures Licensee that, to the best of PWI’s

knowledge, the Licensed Products do not

infringe any patent, copyright, trademark or

trade secret. In the event any legal proceed-

ings are brought against Licensee claiming an

infringement of a patent, copyright, trade-

mark or trade secret based on Licensee’s use

of the Licensed Products, PWI agrees to

defend at PWI’s own expense any such legal

proceeding relating to such claim or claims

and to hold Licensee harmless from any dam-

age incurred or awarded as the result of set-

tlement or judgment against Licensee,

provided Licensee gives PWI prompt written

notice within fifteen (15) days of any such

claim or the institution of any such claims

against Licensee, and further, Licensee coop-

erates completely with PWI in providing all

necessary authority, information, and reason-

able assistance to enable PWI, at PWI’s option,

to settle or defend such claims.

8. U.S. EXPORT COMPLIANCE AND INDEM-

NITY

Licensee agrees to comply fully with all U.S.

export laws and regulations concerning the

purchase and sale of Licensed Software. In

particular, Licensee agrees that any Licensed

Software purchased from PWI shall not be

exported, re-exported, transferred, used, sold,

resold, delivered, diverted, or retransferred,

directly or indirectly, contrary to United States

government export control laws, regulations,

policies, and executive orders.

Without limiting the foregoing, any PWI

Licensed Software is prohibited for export, re-

export, or transfer to embargoed countries of

Cuba, Iran, North Korea, Sudan, and Syria,

as well as to persons, organizations, entities,

or end-users listed on U.S. government denial

lists published by the U.S. Departments of

Commerce, Treasury, or State. Additionally,

absent an authorization from the U.S. govern-

ment or as permitted under the Export

Administration Regulations, the Licensed Soft-

ware is prohibited for export, re-export, or

transfer to any person or entity which will use

it for end-uses proscribed by U.S. export con-

trol regulations, including certain chemical

and biological weapons, missiles, rocket sys-

tems and unmanned aerial vehicles, nuclear

activities, maritime nuclear propulsion, and

terrorism-related activities.

Licensee also agrees to indemnify PWI for any

costs, including but not limited to penalties,

damages, claims, demands, losses, or attor-

ney’s fees and costs, that PWI may incur as a

RIGHT TO USE LICENSE

result of any potential or actual violation of

this provision by Licensee.

9. LIMITATION OF WARRANTY AND LIABILITY.

PWI warrants that the Licensed Products will

perform substantially in accordance with all

written specifications furnished to Licensee by

PWI if properly used. TO THE MAXIMUM

EXTENT PERMITTED BY APPLICABLE LAW, PWI

DISCLAIMS ALL OTHER WARRANTIES, EITHER

EXPRESS OR IMPLIED, INCLUDING, BUT NOT

LIMITED TO, IMPLIED WARRANTIES OF MER-

CHANTABILITY AND FITNESS FOR A PARTICU-

LAR PURPOSE, WITH REGARD TO THE

LICENSED PRODUCTS. TO THE MAXIMUM

EXTENT PERMITTED BY APPLICABLE LAW, IN

NO EVENT SHALL PWI BE LIABLE TO LICENSEE

OR ANY PARTY FOR ANY SPECIAL, INCIDEN-

TAL, INDIRECT, OR CONSEQUENTIAL DAM-

AGES WHATSOEVER (INCLUDING, WITHOUT

LIMITATION, DAMAGES FOR LOSS OF BUSI-

NESS INFORMATION, OR ANY OTHER PECUNI-

ARY LOSS) ARISING OUT OF THE USE OF OR

INABILITY TO USE THE LICENSED PRODUCTS

EVEN IF PWI HAS BEEN ADVISED OF THE POS-

SIBILITY OF SUCH DAMAGES AND REGARD-

LESS OF THE FAULT OR NEGLIGENCE OF PWI.

PWI’s liability to Licensee for damages shall

not exceed the amount of the license fee paid

by Licensee to PWI. PWI will hold Distene

harmless for and against any claims arising out

of or resulting from the use of the Licensed

Software with TetMesh-GHS3D as an included

option.

10. MAINTENANCE AND SUPPORT.

(a) PWI will be responsible for providing cor-

rections for programming errors and periodic

software updates only during the Mainte-

nance Period and during any period when the

Licensee is covered by a Maintenance Agree-

ment from PWI or an authorized representa-

tive of PWI. The specific policy for software

updates and enhancement varies on a per

product basis. PWI warrants that during the

term of this License it will use reasonable

efforts to remedy defects in the unaltered

Licensed Software made known to it by Lic-

ensee. PWI does not warrant that the Licensed

Products will meet all requirements of Lic-

ensee, or that the operation of the Licensed

Software will be uninterrupted or error free,

or that all software defects will be corrected.

(b) During the Maintenance Period, PWI

agrees to telephone hot-line support available

to Licensee. These services may be provided by

PWI or a designated third party.

11. TERMINATION.

Licensee may terminate this License upon

thirty (30) days written notice to PWI. PWI may

terminate this License for any material breach

by Licensee of the terms and conditions con-

tained herein upon thirty (30) days written

notice to Licensee. Licensee will have thirty

(30) days from the date of such notice to cure

the breach, and if the breach is cured to the

satisfaction of PWI, this License will remain in

full force and effect.

Upon termination, Licensee shall promptly: (i)

discontinue use of the Licensed Products; (ii)

remove the Licensed Products from any soft-

ware in Licensee’s possession or control that

incorporates or uses the Licensed Products in

whole or in part; (iii) erase or destroy any of

the Licensed Products contained in the com-

puter memory or data storage apparatus

under the control of Licensee. Licensee’s obli-

gations under Section 6 shall survive any

termination of this License.

12. GENERAL TERMS.

The entire agreement between the parties is

contained herein and in a valid Purchase Order

or Contract, which supersede all proposals,

oral or written, and all other communications

between the parties relating to this Agree-

ment and it may be executed in any number

of counterparts, each of which shall constitute

an original, and all of which taken together

shall constitute one and the same Agreement.

This Agreement is not assignable by Licensee

without prior written permission from PWI.

The section headings and subheadings herein

are for convenience only and shall not affect

the interpretation or construction of this

Agreement. PWI shall not be liable for any fail-

ure or delay in performance due in whole or in

part to any cause beyond PWI’s control.

This Agreement and all transactions under it

shall be governed by the laws of the State of

Texas. All claims arising under or related to

this Right to Use License, Purchase Order or

Contract shall be settled finally and exclusively

by arbitration in accordance with the Com-

mercial Arbitration Rules of the American

Arbitration Association (AAA).

Arbitration shall take place in Dallas, Texas and be administered by the AAA’s Dallas, Texas office.

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Table of Contents

Tutorial Workbook

1. 2D NACA 6412 Airfoil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.11.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.21.2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.21.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.21.4 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.21.5 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.31.6 Database Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.31.7 Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.41.8 Connector Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.41.9 Dimension Trailing Edge Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.41.10 Adjusting Spacing Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.51.11 Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.51.12 Save Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.6

2. Layer Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.12.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.22.2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.22.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.22.4 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.32.5 Geometry Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.32.6 Layer Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.42.7 Working with Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.6

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2.8 Using Layer Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.82.9 The Current Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.92.10 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.10

3. Wing-Pylon with Store . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.13.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.23.2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.23.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.23.4 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.33.5 CAE Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.33.6 Database Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.33.7 Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.43.8 Initial Model Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.43.9 Wing-Pylon Trimming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.53.10 Wing-Pylon Quilt Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.73.11 Store-Fins Trimming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.83.12 Fin Quilt Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.93.13 Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.103.14 Save Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.103.15 CAE Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.11

4. Backward Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.14.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.24.2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.24.3 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.24.4 CAE Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.34.5 Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.34.6 Connector Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.34.7 Adjusting Spacing Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.44.8 Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.54.9 Additional Spacing Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.54.10 New Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.64.11 Domain Copy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.64.12 Connector Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.74.13 More Domains and Block Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.84.14 BCs and Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.94.15 Save Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.104.16 CAE Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10

5. Pipe Flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1

iii

5.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.25.2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.25.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.25.4 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.35.5 CAE Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.35.6 Database Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.35.7 Setting Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.45.8 Feature Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.45.9 Creating Domains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.55.10 Creating Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.65.11 Examine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.65.12 Save Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.85.13 CAE Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.8

6. Pipe In A Cube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.16.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.26.2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.26.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.26.4 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.36.5 CAE Solver Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.36.6 Database Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.36.7 Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.46.8 Outer Surface Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.46.9 Pipe Surface Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.46.10 Boundary Layer Block Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.56.11 Unstructured Domain Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.76.12 Unstructured Block Creation and Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . .6.76.13 Save Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.86.14 CAE Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.8

7. Boeing 747 Nacelle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.17.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.27.2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.27.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.27.4 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.37.5 CAE Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.37.6 Database Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.37.7 File Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.37.8 Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.47.9 Database Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.4

iv

7.10 Surface Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.57.11 Boundary Layer Block Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.67.12 Remaining Connector and Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.77.13 Unstructured Block Creation and Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . 7.87.14 Set Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.107.15 Save Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.117.16 CAE Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.12

8. Transition Duct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.18.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.28.2 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.28.3 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.28.4 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.38.5 CAE Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.38.6 Database Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.48.7 Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.48.8 Database Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.48.9 Surface Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.58.10 Adjusting Spacing Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.58.11 Domain Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.68.12 Boundary Layer Block Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.78.13 Remaining Connector and Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.88.14 Structured Block Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.108.15 Set Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.118.16 Save Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.128.17 CAE Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.12

9. Re-Entry Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.19.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.29.2 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.29.3 Programming Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.29.4 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.49.5 Define Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.79.6 Connector Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.89.7 Adjusting Connector Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.119.8 Domain Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.129.9 Solve Domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.139.10 Extrude Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.149.11 Export Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.149.12 Execute Your Script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.15

v

10. Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10.1

vi

1.1

Chapter 1

2D NACA 6412 Airfoil

1.2 Pointwise Tutorial Workbook

Guide

1 .1 Overv iew

This section contains a brief overview of generating a basic 2D mesh within Pointwise. If you have never used Pointwise before, you should work through this and the other tutorials before applying Pointwise to actual problems.

1.2 Commands

In Table 1.1, you will find a display of the most commonly used toolbar commands for this tutorial. Feel free to reference the table as you work through following sections.

1.3 Geometry

The geometry to be meshed is a 2D NACA 6412 airfoil. NACA airfoils are commonly used for validation of new CFD methods.

F igure 1.1: The geometr y to be meshed i s a 2D NACA 6412 a i r fo i l .

1.4 Topology

An O-topology grid created by hyperbolic extrusion will be used in meshing the 2D NACA 6412.

Table 1.1: Quick Reference for Toolbar Commands

Toolbar Command Toolbar Command

Connectors on Database Entities

Spacing Constraints Mask

All Masks On/Off Spacing

Points Off

Points On

If you are unsure of which toolbar button to click for a certain command in the tutorial, use the Quick

Reference (Table 1.1) at the beginning of each tutorial. It will show the major toolbar commands used in that tutorial along with the commands’ associated buttons.

1.3

Guide

F igure 1.2: The topology to be used in mesh ing the 2D NACA 6412 i s a s imple hyperbol ica l l y ext ruded “O” topology gr id .

1.5 Gett ing Started

Start Pointwise by one of the following methods:

• Enter the string pointwise at the command prompt (Unix/Linux).

• Double-click the Pointwise desktop shortcut (Windows).

• Double-click the Pointwise application in Applications/Pointwise (Mac).

After a few seconds Pointwise will start, and the graphical user interface should appear. Remember that Table 1.1 can be used for reference if you are not sure which command toolbar buttons to select as you work through this tutorial.

1.6 Database Import

The geometry you will use for this example is in an IGES file named NACA6412.igs . It is located in your Pointwise installation directory in the /tutorials/2DAirfoil/ directory. You may want to copy it to a local directory before trying to import it into Pointwise.

1. File, Import, Database

2. Select NACA6412.igs from the file browser.

It is not always obvious how many entities are included in a geometry file simply from looking at the Display window. Use the List headers, import summary in the Messageswindow and Select, Entity Count for database entity totals. The database geometry for this tutorial includes very small curves at the trailing edge. Some operations may require zooming up on this portion of the geometry.


Guide

3. Open

Because you are importing an IGES database file, you will be presented with an Import Database options panel where you can choose whether Pointwise will use the visibility settings present in the file (default) or Show All entities. You will also be given an option to, if trimmed surfaces are present in the file, assemble them automatically into models and quilts.

For this tutorial, we will use the default visibility settings. Because the IGES file only contains curves, we will not use the quilt or model assembly options.

4. OK

1.7 Defaults

Before you begin constructing your grid, you will need to set the default number of grid points that will be applied to all of the new connectors you create.

1. Defaults

2. Make sure the Connector frame is checked.

3. Toggle on Dimension.

4. 75

This setting defines how many grid points will be applied to each newly created connector.

1.8 Connector Creat ion

Use the Connectors on Database Entities command to quickly create the connectors that define the shape of the NACA airfoil.

1. Select all four database curves in the List.

2. Click Connectors on Database Entities on the toolbar.

To make the connector grid points visible, use the Points On command to change the way they are drawn.

3. Select all four connectors in the List.

4. Click the down arrow next to Points Off on the toolbar and select Points On.

1.9 D imens ion Tra i l ing Edge Connectors

There are more grid points than necessary to resolve the trailing edge base of the airfoil. Use an average spacing to set a new dimension for these two connectors. It may be necessary to zoom in on the trailing edge to select these connectors in the Display window, or simply select them using the List.

Often using the List is quicker for entity selection, particularly when using all available entities of a particular type. This can be done quickly by clicking an entity type icon in the Listwithout any changes to the Mask.

1.5

Guide

1. Select the two small connectors on the trailing edge.

2. Grid, Dimension

3. Toggle on Average Δs.

4. 0.0005

5. Dimension

6. OK

These connectors now have a much more reasonable dimension of 4 grid points each. This same spacing value will be used to cluster the upper and lower connectors’ grid points to the trailing edge in the next step.

1.10 Adjust ing Spac ing Constra ints

Spacing constraints within the mesh will help control how tightly the grid lines are clustered in certain regions. The spacing constraints you will need to set will cluster grid points toward the leading and trailing edges of the airfoil to resolve the geometric shape. The initial step size used for the extrusion later will cluster grid lines to the airfoil itself.

1. Click the All Masks On/Off button to mask all entity types.

2. Check the Spacing Constraints mask.

This sets the Pick Mask so that only spacing constraints will be selectable from the Display window.

3. Select the spacing constraints at the trailing edge on the upper and lower airfoil connectors.

4. Click in Spacing on the toolbar.

5. 0.0005

6. Select the spacing constraints at the leading edge on the upper and lower airfoil connectors.

7. 0.005

1.11 Domain Creat ion

The rest of the mesh will be created via domain extrusion. All four connectors will be extruded in a normal direction outward from the airfoil. The outer boundary will be the final front of the extrusion.

1. Check the Connectors mask.

2. Select all connectors.

3. Create, Extrude, Normal

4. Done

5. Click on the Normal, Attributes tab.

The spacing constraint locations and values can be seen in the below image.

To select multiple constraints, like at the trailing edge, hold the Ctrl key during selection or simply use a selection box in conjunction with the Mask.


Guide

6. Check the Step Size frame.

7. Enter 0.0001 for Initial Δs.

8. Check the Orientation frame.

9. Press Flip if the marching vectors do not point out from the airfoil.

10. Click on the Normal, Run tab.

11. Enter 91 for Steps .

12. Run

13. OK (dom-1 is saved.)

F igure 1.3: The f in i shed mesh d isp lays the exce l lent or thogonal i ty produced by hyperbol ic ext rus ion.

1.12 Save Project

Saving your project file allows you to easily come back and work with your mesh in Pointwise while retaining all previously used layer and display settings. You are encouraged to save a project file for every database and/or meshing case on which you work.

1. Click Save on the toolbar.

2. Save the project file using the standard file browser that appears.

The location of the branch connector, the one spanning between the trailing edge and the outer boundary, is determined by where the initial extrusion front loop begins and ends. This tutorial uses the default location at the trailing edge. You can use the Edge Assembly tab of the Normalextrusion command to control where the beginning and ending of the initial edge loop is and thus the location of the connector between the airfoil and outer boundary.

2.1

Chapter 2

Layer Manager


Guide

2 .1 Overv iew

This section contains an overview of using the Layer Manager in Pointwise. The Layer Manager is used to organize database entities into logical sets, or layers, for display control. Display of each layer or sets of layers can be quickly turned on or off to control which entities are rendered. In this way, you can quickly isolate the portion of a complex database you need for the task at hand and turn off the remaining entities so they do not clutter the Display window.

In this tutorial, you will import a geometry from an IGES file and organize it into layers. You will also modify some of the database’s display attributes to make it easier to see the shape of the geometry. In addition, you will try out several selection methods to show how each has advantages for particular selection situations.

2.2 Commands


2.3 Geometry

F igure 2.1: The tutor ia l geometr y represents a s impl i f ied 747 nace l le and centerbody.



Recall View +X

Choose Color

Wireframe

Shaded

All Lines

No Lines


Reference (Table 2.1) at the beginning of each tutorial. It will show the major toolbar commands used in that tutorial along with the commands associated buttons.

2.3

Guide

The geometry to be organized into layers is a notional 747 nacelle and centerbody.

2.4 Gett ing Started

Start Pointwise by one of the following methods:

• Enter the string pointwise at the command prompt (Unix/Linux).

• Double-click the Pointwise desktop shortcut (Windows).

• Double-click the Pointwise application in Applications/Pointwise (Mac).

After a few seconds Pointwise will start, and the graphical user interface should appear. Remember that Table 2.1 can be used for reference if you are not sure which command toolbar buttons to select as you work through this tutorial.

2.5 Geometry Import

The geometry you will use for this tutorial is an IGES file named 747_nacelle.igs. It is located in your Pointwise installation directory in the /tutorials/LayerManager/ directory. You may want to copy it to a local directory before importing it into Pointwise.

Assuming you have copied 747_nacelle.igs to your local directory, import it via the Fi le menu:

1. Fi le, Import, Database

2. Double-click on 747_nacelle.igs.

3. OK

The file will be imported into Pointwise. It should appear as in Figure 2.2depending on your current view orientation.

F igure 2.2: The 747 nace l le geometr y appears as a b lue wiref rame when f i r s t imported.

The Layer Manager is just a way to organize a database. Sets of entities are added to layers and entity display can be controlled on a per layer basis so that many entities can be controlled together.


Guide

2 .6 Layer Ass ignment

You will organize the geometry into three layers corresponding to the centerbody, the inner nacelle, and the outer nacelle. To help visualize the process, you will change the display attributes of the database surfaces as you assign them to layers.

The first layer to create is the centerbody. The centerbody surfaces are easily selected if you look down the axis of the nacelle, which is the x-direction.

1. Click Recall View +X on the toolbar. The Display window should look like the Guide figure after you switch to the +X view.

2. Use a selection box to select the centerbody surfaces by moving the cursor to a point slightly to the left and above the centerbody in the Display window, then holding down the left mouse button and dragging to the right and below the centerbody, and releasing the mouse button (see Figure 2.3).

F igure 2.3: Use a box se lect ion to grab the centerbody database sur faces .

3. Layers

4. Enter 10 for Layer Number in the Assign Layer frame.

Note that it may be necessary to scroll down to see all the contents of the Assign Layer frame. This will assign the selected entities to layer 10, and you will see a new entry for layer 10 appear in the Layers table.

5. Double-click on the Description field for layer 10 in the browser at the top.

6. Enter Centerbody as the description for this layer.

Many selection operations are easier in one view than in another. To select the centerbody surfaces, using the Recall View +X toolbar button quickly gives a view that makes them easy to select. The 747 nacelle geometry looks like this in a +X view:

2.5

Guide

7. Turn off layer 10 by toggling the check box off in the browser column labeled On. (This makes subsequent selection from the List much easier.)

8. List

9. Expand the database entity list.

10. Click on the Name header to sort the database entities by names.

11. Select from the list all the database surfaces forming the outer part of the nacelle. Their names begin with nac_out as shown in Figure 2.4.

F igure 2.4: The outer nace l le database surface names a l l beg in wi th nac_out .

12. Layers

13. Enter 20 for Layer Number in the Assign Layer frame to assign the outer nacelle surfaces to layer 20.

14. Double-click on the Description field for layer 20 in the browser at the top.

15. Enter Outer nacelle as the description for this layer.

16. Turn off layer 20 by toggling the check box off in the browser column labeled On.

17. List

18. Select all the remaining database surfaces with names beginning with nac_inn, which will be all the inner nacelle surfaces.

19. Layers

20. Enter 30 for Layer Number to assign the inner nacelles surface to layer 30.

Use the Description field in the Layers table to give short descriptions of layers you create. It is not required, but it makes it much easier to later remember which entities are in a layer.


Guide

21. Double-click on the Description field for layer 30.

22. Enter Inner nacelle as the description for this layer.

2.7 Working with Layers

You have assigned database entities to three layers. The centerbody surfaces are in layer 10. The outer nacelle surfaces are in layer 20, and the inner nacelle surfaces are in layer 30. Now use the layer manager to isolate some entities and change the way they appear.

1. In the Layer Manager table, click on the row containing layer 10.

2. Click Isolate to display the centerbody surface and turn off all the other layers.

3. Use Ctrl+A to select all.

4. Click Choose Color on the toolbar to open the Select Color dialog.

5. Enter 150 for Red, 150 for Green , and 150 for Blue.

6. OK

7. Click the down arrow next to Wireframe on the toolbar and select Shaded.

8. Click the down arrow next to All Lines on the toolbar and select No Lines.

9. Click on an empty area of the Display window to unselect all entities.

This deselection is done just so that the display attribute changes are easily seen. The centerbody surfaces should be displayed as shown in Figure 2.5.

F igure 2.5: The centerbody surfaces have been i so lated and rendered as shaded sur faces .

Sometimes layer assignments are already defined in a database when you import it, which is great. If the entities are not already layered, you can layer them in Pointwise as we are doing in this tutorial so working with the database will be easier.

2.7

Guide

In a similar manner, change the display of the nacelle outer surfaces and inner surfaces.

1. Layers

2. In the Layer Manager table, click on the row containing 20.

3. Click Isolate to display the outer nacelle surfaces and turn off all the other layers.

4. Ctrl+A to select all.

5. Click the down arrow next to rgb(150, 150, 150) on the toolbar and select Choose.

6. In the Select Color dialog, enter 255 for Red, 170 for Green, and 255 for Blue.

7. OK

8. Click Shaded on the toolbar.

9. Click No Lines on the toolbar.


11. Layers

12. Click on the row containing layer 30.

13. Click Isolate to display the inner nacelle surfaces and turn off all the other layers.

14. Type Ctrl+A to select all.

15. Click the down arrow next to rgb(255, 170, 255) on the toolbar and select Choose.

16. In the Select Color dialog, enter 85 for Red, 255 for Green, and 127 for Blue.

17. OK

18. Click Shaded on the toolbar.

19. Click No Lines on the toolbar.


Now turn all the surfaces back on and see what it looks like.

1. Layers

2. Click on the All On button, which will turn on all layers. The display should look like Figure 2.6.

You can use the Attributestoolbar commands to change the way entities are displayed. It is just another way to organize your data or even to make the display more attractive.


Guide

.

F igure 2.6: A l l database sur faces are d i sp layed in shaded s ty le wi th d i f ferent colors for each major reg ion of the geometr y.

2.8 Us ing Layer Sets

Layer Sets give you even more ways to organize a database. A layer set stores the current layer and the on or off setting for each layer. In this way, you can set several layers to be on and the remainder off to make it easy to isolate components or assemblies in the database.

For example, you may want to display all the nacelle surfaces, both inner and outer, at once. A layer set will do just that. Or, you may want to only work with the centerbody and the inner nacelle surfaces so you can grid the volume between them. Again, a layer set is a good solution.

Make the two layer sets described in the preceding paragraph.

1. Click on the row in the Layers table that contains layer 10.

2. Click on the Off button.

3. Open the Layer Sets frame.

4. Click Save.

5. Double-click on the text set-1 in the Name field in the Layer Sets table.

6. Enter Nacelle as the new name for this layer set.

7. In the Layers frame, check the box in the On column for layer 10.

8. Uncheck the box in the On column for layer 20.

Now only the centerbody and inner nacelle surfaces are on.

9. In the Layer Sets frame, click on Save.

10. Double-click on set-2 in the Name field.

Layer sets store the on and off states of every layer, as well as which is the current layer. An individual entity can only be in one layer, but each layer can be part of many layer sets.

2.9

Guide

11. Enter Flowpath as the new name for this layer set.

You now have two layer sets, named Nacelle and Flowpath. To quickly recall one of the layer sets, go to the Layer Sets frame, select the layer set you want in the table, and then click on Restore. Go ahead and try it a few times to see how easy it is to switch back and forth.

2.9 The Current Layer

The last layer concept discussed is the current layer, or current working layer. The current layer, which is always displayed, is denoted by the gold chevron in the On column of the Layers table. The current layer is the layer into which any new entities you create will be placed. Only one layer at a time can be the current layer.

As an example, make some CFD model specific geometry and place it into a new layer so it does not get mixed up with the existing database.

1. Click the All On button to turn on display of all layers.

2. Check Show Empty Layers to turn on display of all layers in the Layers table.

3. Scroll down the Layers table to layer 40 and select that row.

4. Click on Set Current to make layer 40 the current layer.

5. Double-click on the Description field for layer 40.

6. Enter CFD geometry as the description for this layer.

7. Uncheck Show Empty Layers to shorten the Layers table.

8. From the menu bar, Create, Planes to open the Planes panel.

9. Select Constant X, Y, or Z in the Plane Mode frame.

10. Enter 5.0 in the X = field.

11. Apply (An X = 5 plane is created.)

12. Enter 70.0 in the X = field.

13. OK (An X = 70 plane is created and the Planes panel closes.)

14. From the menu bar, Create, Intersect.

15. Select Group A in the Entity Selection frame.

16. Select the two planes you just created.

17. Select Group B.

18. Select all database entities.

19. Intersect

20. OK (Intersection curves between the planes and the remaining geometry are created and the Intersect panel closes.)

21. Layers

The current layer is where any new entities you create will be placed. It cannot be turned off. If you want to turn off the layer that happens to be the current layer, choose a different current layer, and then you will be able to turn it off.


Guide

Note that layer 40 now has 18 database entities in it. These are the 2 planes you created plus the entities created by the intersection operation. Newly created database entities will continue to be added to layer 40 until you change the current layer.

What happens if you restore a saved layer set?

1. In the Layer Sets frame, select Flowpath.

2. Restore (Alternatively, double-clicking in the Current, On, or Off columns of the Flowpath row will restore the Flowpath layer set also.)

Note layer 40 is still on even though it was empty when the layer set was defined. By default, all layers are on, even empty layers. If an empty layer is on in the layer set, and you later add entities to that layer, they will be displayed when the layer set is restored. Layer 30 is now the current layer because it was saved that way in the Flowpath layer set. If you create any new entities they will go into layer 30 unless you change the current layer.

2.10 Summary

Layers are a way to organize your database. They are particularly useful for databases with many entities, which can cause screen clutter and possibly reduced graphics performance.

The Layer Manager is used to move entities between layers and control the display of layers. Many times a database already contains layer information, which Pointwise will import and use. If the layer assignments do not already exist, a little time spent organizing the database with the Layer Manager can greatly simplify and speed up your workflow when using a complex, detailed geometry.

Using layers to control database entity visibility not only reduces visual clutter, but can also greatly accelerate entity selection by reducing the available pick list of database entities. Database entities in off layers are also not available as candidates for grid entity projection.

3.1

Chapter 3

Wing-Pylon with Store


Guide

3 .1 Overv iew

This section contains a brief overview of the operations necessary to clean-up a wing-pylon and store geometry for the creation of a watertight unstructured surface mesh within Pointwise. If you have never used Pointwise before, you should work through this and the other tutorials before applying Pointwise to actual problems.

3.2 Commands


3.3 Geometry

The geometry to be meshed is a wing-pylon with a missile store. The surfaces contained within the geometry are completely untrimmed , which means that some surfaces extend through other surfaces.

F igure 3.1: The wing-py lon and s tore geometr y conta ins surfaces which extend into other surfaces and requi re fur ther process ing.



Assemble Models

Unstructured

Assemble Quilts

Domains on

Database Entities

Wireframe

Shaded


Reference (Table 3.1) at the beginning of each tutorial. It will show the major toolbar commands used in that tutorial along with the commands’ associated button.

3.3

Guide

3.4 Topology

The topology will consist of unstructured surface domains that describe the upper and lower surfaces of the wing, the three sides of the pylon, and all missile and fin surfaces. The geometry will be organized into models, then trimmed and organized into quilts prior to surface mesh creation.

3.5 CAE Se lect ion

Before starting a meshing project, it is always a good idea to first set the grid dimension and CAE solver. This helps avoid any situations in which you create a mesh type that is unsupported by your solver.

1. CAE, Set Dimension, 2D

2. CAE, Select Solver

3. CGNS

4. OK

You should see the name of your currently selected CAE solver, CGNS, and the grid dimension, 2D, appear in the left hand corner of the Pointwise status bar.

3.6 Database Import

The geometry you will use for this example is in an IGES file named WingStore.iges. It is located in your Pointwise installation directory in the /tutorials/WingStore/ directory. You may want to copy it to a local directory before importing it into Pointwise.


2. Select WingStore.iges from the file browser.

3. Open

Because you are importing an IGES database file, you will be presented with an Import Database options panel where you can choose whether Pointwise will use the visibility settings present in the file (default) or Show All entities. You will also be given an option to, if trimmed surfaces are present in the file, assemble them automatically into models and quilts based on an edge tolerance and bending angle, respectively.

For this tutorial, we will use the default visibility settings. Because the IGES file only contains B-spline surfaces, we will not use the quilt or model assembly options.

4. OK

When using solid modeling, make sure you always assemble surfaces into as few models as possible. First, create any surfaces necessary to fill in holes or large gaps, then trim any models that overlap but need to form a watertight bond. Finally, create quilts in your models to define your meshing regions.

These simple steps will make the next step, mesh generation, more automated and quicker to finish.


Guide

You should now have a wireframe representation of the geometry in your display similar to Figure 3.2.

F igure 3.2: The wing-py lon geometr y wi l l in i t ia l l y import in a wiref rame representat ion.

3.7 Defaults


1. Defaults



4. 0.01

5. Enter 10.0 for Max. Angle.

6. Check Use Surface Curvature.

7. Check the Unstructured Domains and Blocks frame.

8. Enter 10.0 for Max. Angle.

The Max. Angle values that you specified for connectors and unstructured domains allows you to specify how closely the discrete mesh matches the analytical surface. It checks the maximum angle between adjacent line segments in a connector or between cell centroid normals and vertex surface normals in a domain. If it exceeds the Max. Angle specified in the Defaults, points will be inserted until the default is met.

3.8 In i t ia l Model Assembly

The first step in processing the geometry is ensuring that the geometry is watertight. In other words, you need to ensure there are no undesirable gaps or holes between adjacent surfaces. As long as database surfaces are contained within a model in Pointwise, they will be considered watertight with each other. Let’s assemble models out of the surfaces just imported.

1. Select all database surfaces.

When using a default Max. Angle or Max. Deviation control to make your connector dimensions match the curvature of the analytic surface more closely, make sure that you enable the Use Surface Curvature default. This option will ensure that the connector dimensions are based on, not only the 2D curvature in the direction of the underlying database curve, but also on the 3D curvature of the analytic surface on which the curve is based.

3.5

Guide

2. Click on Assemble Models on the toolbar.

In the List panel, you can see that the B-Spline surfaces selected for assembly into a model were automatically promoted into quilt entities and seven models now exist. By making the following display changes, you should be able to get a better look at the quilts.

1. Select all database quilts.


F igure 3.3: The seven models are now watert ight groupings of database surfaces .

Your display should now look like Figure 3.3. Even though the models are not rendered, they exist to ensure that all the quilts contained within them are watertight with each other. At this point it is important to note that the seven models just created are not watertight with each other. They will need to be trimmed together first so they share common edges. This will allow them to be assembled into two watertight models: one for the wing-pylon and one for the store-fins.

3.9 Wing-Py lon Tr imming

In the initial inspection of the geometry (Figure 3.1), the pylon surfaces were seen to extend through the wing surfaces. To make the pylon watertight with the wing, you will need to trim them with each other. To make trimming the models together easier, first check the orientation of the two models in question and make sure they are oriented in a similar manner.

1. Select the wing and pylon models.

2. Edit, Orient

You should now see red arrows that emanate from both models. In Figure 3.4, the inset shows the pylon orientation arrows as seen from above. To improve visibility the background for the inset was changed.

When trimming entities, you get the best results if the groups of entities you are trimming against each other form watertight closed surfaces or a closed loop of surfaces. Having all surfaces in models, and trimming the models together instead of the surfaces, ensure that this is the case.


Guide

F igure 3.4: The Ed i t ,Or ient command shows the wing model i s or iented outwards and the py lon model ( inset ) i s or iented inwards .

Both models need to have their orientation arrows pointing either outside or inside of the model. Since the wing model is already oriented to the outside, just go ahead and reorient the pylon in the same direction.

3. Select only the pylon model.

4. Reverse Normal

5. OK

You are now ready to trim the wing and pylon models with each other.

1. Select the wing model.

2. Edit, Trim By Surfaces

3. Select the pylon model.

The wing model should now be in Group A and the pylon model in Group B. Since you do not want to keep the part of the pylon that is inside the wing nor the part of the wing that is inside the pylon, you will need to change one of the trimming options before you proceed.

4. Uncheck Keep Inside in the Advanced frame.

5. Imprint

6. OK

You should now see that the pylon model is fitted to the underside of the wing shape (Figure 3.5).

F igure 3.5: The py lon model has been t r immed with the wing model so that they can form one watert ight mode l .

If you are not sure which surfaces you need to discard, check both the Keep Inside and Keep Outside options in the Advanced frame. Once you have clicked Imprint, you can then use the Apply and Select command in the Trim By Surfaces panel to choose which quilts to keep.

3.7

Guide

Now that the wing and pylon share a common edge, go ahead and assemble the two models into one.

1. Select the wing and pylon models.


As a result of the assemble operation, you should see one model that represents the wing-pylon in the List panel.

3.10 Wing-Pylon Qui l t Assembly

Now that the wing-pylon region of the geometry is a watertight model, you will assemble the quilts within the model. Quilts allow you to define the meshing regions on the geometry, or rather the surface collections across which you want one domain.

Looking at the pylon, you will ideally want three domains: one on each side of the pylon and one that covers the bottom. Since there are discontinuities that bound those regions on the pylon, we can assemble the quilts in those regions into larger quilts automatically based on a bending angle between the quilts.

1. Create, Assemble, Quilts

2. Click on the +X view on the toolbar.

3. Zoom in to the pylon area and draw a selection box around just the pylon quilts (Figure 3.6). You may need to hold the Shift key while drawing your selection box to obtain just the pylon quilts within the box.

F igure 3.6: Se lect ion of the py lon qu i l t s can be accompl i shed by us ing a se lect ion box in conjunct ion with the Sh i f t key.

4. Uncheck Use Default.

5. Enter 45.0 for Angle.

6. Assemble

7. Apply

The default selection box style in Pointwise selects all entities within the box as well as those touching it. In cases where you need to select just the entities inside the box, simply hold the Shift key and carefully draw your selection box about the desired entities. Using the Shift key in this situation momentarily switches the selection box to the mode of selecting only the entities completely within the box.


Guide

You should now have three quilts that describe the two sides and the bottom of the pylon.

For the wing you will want separate domains for the upper and lower halves respectively. This means you will need to assemble one quilt that is the upper portion of the wing and a second quilt across the lower wing.

8. Select the two quilts on the upper portion of the wing (wing-zmin-quilt and wingtip-zmin-quilt).

9. Assemble

10. Apply

11. Select the two quilts on the lower portion of the wing (wing-zmax-quilt and wingtip-zmax-quilt).

12. Assemble

13. OK

The wing-pylon geometry has now been cleaned up and is ready for meshing. Before you do any meshing, it would be wise to first trim the store with the fins and create quilts in the same manner you just treated the wing-pylon.

3.11 Store-F ins Tr imming

Since you already created models out of the store and fins in Section 3.8, you simply need to orient and trim those models together at this point. Let’s check and correct (if necessary) the orientation of the fin models first.

1. Select the four fin models.

2. Edit, Orient

Visual inspection of the red orientation arrows show that three out of the four fin models are oriented outwards. One of the fin models orientation arrows point inwards. You will need to reorient the single fin model before proceeding.

3. Select the fin whose orientation arrows point inward.

4. Reverse Normal

5. OK

All four fin models are now oriented outwards and should still be selected. Use the Trim By Surfaces command now to trim them with the store model.

6. Select only the store model.

7. Edit, Trim By Surfaces

8. Select the four fin models.

9. Make sure that Keep Inside is unchecked.

10. Imprint

11. OK

When you assemble multiple quilts into one larger quilt (or multiple models into one model), the final quilt or model will inherit the name of one of the original quilts or models. To make it easier to identify the new larger quilt or model, select the quilt or model and click the Attributes command on the toolbar. Within the attributes for the entity you can change the entity name which will make it easier to identify in

the List panel.

3.9

Guide

As with the wing-pylon trimming, the parts of the models that were considered inside (based on the models’ orientations) were trimmed away for the store and the fins. The fins should now be trimmed by the shape of the store body and the store should contain holes where the fins intersect it (Figure 3.7).

F igure 3.7: Tr imming the s tore and the f ins cuts away the port ion of the f ins with in the s tore and creates ho les in the s tore at the f in intersect ions .

Since the store and fins now have clearly defined intersections where they are watertight, these five models can now be assembled into one.

1. Select the store and four fin models.


One model now exists that describes the closed volume of the store and its fins.

3.12 F in Qui l t Assembly

Now you need to define the meshing regions for the store-fins portion of this geometry. The three quilts that the store is composed of already form the regions desired for its surface domains so no further quilt assembly is necessary. On the fins, you will want a domain on each side of a fin and one domain on the tip. Since each fin currently has two quilts that describe the tip, you’ll want to assemble those into one quilt per tip.

1. Select the eight quilts that form the fin tip regions.

2. Click on Assemble Quilts on the toolbar.

You should now have one quilt for each fin tip. The geometry is now ready for mesh generation.

If you find that you have multiple quilts you cannot assemble into one quilt, you may need to join their models together first. In Pointwise, quilts can only be assembled together if they reside in the same model.

This is a good reason to assemble models as the first step of your geometry processing.


Guide

3 .13 Domain Creat ion

Because you have spent time ensuring that your geometry is watertight and well-defined, the creation of the surface meshes on the geometry is a simple process.

1. Click Unstructured on the toolbar.

2. Select the wing-pylon model and the store-fin model.

3. Click on Domains on Database Entities on the toolbar.

The resulting surface domains should look like those in Figure 3.8.

F igure 3.8: The Domains on Database Ent i t ies command a l lows domains to be c reated automat ica l l y.

To make your display look similar to Figure 3.8, make the following changes:

1. Uncheck View, Show Database

2. Select all domains.


3.14 Save Project

Saving your project file allows you to easily come back and work with your mesh in Pointwise while retaining all previously used layer and display settings. We encourage you to save a project file for every database and/or meshing case on which you work.


2. Save the project file using the file browser.

When you are working on complex geometries and grids, it is easy to develop a cluttered display. To clear up your display and make it easier to work with components of your geometry or grid, try using the following View commands: Show Domains, Show Connectors, Show Nodes, Show Database, Show Axes. By toggling off one of these commands you can quickly remove the display of that type of entity from view.

3.11

Guide

3.15 CAE Export

You can now export your 2D surface mesh to CGNS and use it in other applications.


2. File, Export, CAE

3. Save the CGNS files using the file browser.

When you need surface grids for other applications, exporting them out of an existing grid is simple. You need to first make sure that you’ve set your CAE Dimension to 2D, then select the domains you wish to export. The File, Export, CAE command will write only those domains out in the 2D format for your CAE.


4.1

Chapter 4

Backward Step


Guide

4 .1 Overv iew

This section contains a brief overview of generating basic 2D and 3D structured meshes within Pointwise. If you have never used Pointwise before, you should work through this and the other tutorials before applying Pointwise to actual problems.

4.2 Commands


4.3 Topology

F igure 4.1: The topology to be used in meshing the backward fac ing s tep uses mul t ip le domains to improve or thogonal i ty.



2 Point Curves

Assemble Blocks

All Masks On/Off

Domains Mask

Connectors Mask

Spacing

Constraints Mask

Spacing

Initialize

Points Off

Points On



4.3

Guide

The geometry to be meshed is a backward facing step which has been a common test case used for many separated flow studies. Due to the simplicity of the geometry, no database entities are required to create the mesh.

4.4 CAE Se lect ion

Before starting a meshing project, it is always a good idea to first select your CAE solver. This helps avoid any situations in which you create a mesh type which is unsupported by your solver.


2. CGNS

3. OK

You should see the name of your currently selected CAE solver, CGNS, in the left hand corner of the Pointwise status bar.

4.5 Defaults

Before you begin, you will need to set the default number of grid points that will be applied to any new connectors you create.

1. Defaults


3. Toggle on Dimension .

4. 30


You will use the 2 Point Curves command to quickly create the connectors that define the topology seen in Figure 4.1.

1. Click 2 Point Curves on the toolbar.

2. Click Entity Type, Connector.

3. Click in Point Placement, XYZ.

4. 0 0 0 (Point A)

5. 20 0 0 (Point B, con-1 is saved.)

6. Enter

Pressing Enter again in the XYZ text field accepts the current value as the first point in the next 2 Point Connector.

7. 60 0 0 (Point E, con-2 is saved.)

This diagram shows the first two connectors and labels for their nodes:


Guide

8. OK

If the connectors are hard to see, you can use the Ctrl+R accelerator at this time to reset the view so they are both visible.


Spacing constraints within the mesh help control how tightly the grid lines are clustered in certain regions. For this grid, you will need to set constraints on the connectors to cluster grid points towards the step (Point B). These spacings will then be propagated through the mesh when you extrude domains from the connectors.

Prior to setting the spacing constraints, you should enable the display of grid points on the connectors. This will allow you to clearly see distribution changes as you adjust your spacing constraints.

1. Select both connectors.

2. Click the down arrow next to Points Off on the toolbar and select Points On.



This sets the Selection Mask so that only spacing constraints will be selectable from the Display window.

5. Select the spacing constraint at Point A.


7. 1.0

8. Select both spacing constraints at Point B.

9. 0.1

10. Select the spacing constraint at Point E.

11. 2.0

Both connectors now have the distribution that needs to be carried through the rest of the mesh (Figure 4.2).

F igure 4.2: Gr id points on the connectors are c lustered towards the locat ion of the backward step.

Rendering the connectors with grid points displayed, while useful for distribution tasks, makes it difficult to distinguish between them for later

The spacing constraint locations and values can be seen in the below diagram.

To select multiple constraints, like at Point B, hold the Ctrl key during selection.

4.5

Guide

operations. Turn off the display of grid points for the connectors now by changing them back to their original attributes settings.

1. Check the Connectors mask.

2. Select both connectors.

3. Click the down arrow next to Points On on the toolbar and select Points Off.


The remainder of the mesh will be created via domain extrusion. con-2 will be extruded in the -Y direction to create dom-1 . con-1 and con-2 will be extruded in the +Y direction to create dom-2.

1. Select con-2 .

2. Create, Extrude, Translate

3. Enter 29 for Steps.

4. Enter 0 -1 0 for Direction.

5. Enter 8 for Distance.

6. Run


You have now created connectors BC, CD, DE, and domain 1. Now create domain 2:

1. Select con-1 and con-2 .

2. Create, Extrude, Translate

3. Done

4. Click Use Y Axis.

5. Enter 20 for Distance.

6. Run


Now that all of your domains have been created you can move on to the next step, setting up the remaining spacing constraints for the mesh.

4.9 Addi t ional Spac ing Constra ints

You now need to apply a few vertical spacing constraints in the domains to cluster the grid lines in the Y direction towards the step wall. Once they are set, you will need to re-initialize the domains to ensure that the interior of the domains reflects the new constraints accurately.

1. Select the Y-directed spacing constraints at Points A, B, and E.

When performing a translational extrusion, either a vector or a principal axis can be used to define the direction your extrusion should march.


Guide


3. 0.1

4. Check the Domains mask.

5. Select both domains.

6. Click Initial ize on the toolbar.

The 2D version of your mesh is now complete and should look similar to the mesh seen in Figure 4.3.

F igure 4.3: The domains have a more appropr iate concentrat ion of gr id l ines af ter ad just ing the spac ing const ra ints .

4.10 New Defaul ts

You now need to set a new default number for grid points that will be applied to all of the new connectors created.

1. Defaults

2. Make sure the Connector frame is checked and open.


4. 21

4.11 Domain Copy

To accelerate the construction of this mesh, you will first copy the two existing domains and translate the copies to a new Z-axis coordinate.

1. Select the two domains.

2. Ctrl+C (To copy the domains into the paste buffer.)

3. Ctrl+V (To paste the copied domains.)

The diagram below of the Y-directed spacing constraints has the display of domains turned to Hidden. This makes it easier to view the connectors and constraints in question.

4.7

Guide

The Paste panel is automatically opened providing all the various transformation commands available to be used on the copied entities.

4. Translate

5. Enter 0 0 15 for Offset Vector. (Sets the offset direction and distance.)

6. OK (Closes Translate panel.)

7. OK (Closes Paste panel.)

At this time you may wish to change the orientation of the model, if you have not already done so, in order to more clearly see the newly copied domains. An orientation similar to that in Figure 4.1 will facilitate connector creation in the next step. Refer to Section 2.5.3 of the User Manual for more information on model manipulations.


Before the remaining domains and then blocks can be created, you need to create connectors between the two sets of domains. Use the 2 Point Curvescommand to quickly create the connectors seen in Figure 4.1. To avoid accidentally picking an interior grid point, turn off the display of the domains first.

1. View, Show Domains



4. Click on point A in the Display window.

5. Click on point H. (con-17 is saved.)

6. Click on point I.

7. Click on point B. (con-18 is saved.)

8. Click on point C.

9. Click on point J. (con-19 is saved.)

10. Click on point K.

11. Click on point D. (con-20 is saved.)

12. Click on point E.

13. Click on point L. (con-21 is saved.)

14. Click on point M.

15. Click on point F. (con-22 is saved.)

16. Click on point G.

17. Click on point N. (con-23 is saved.)

18. OK

The two domains previously extruded will be copied.

The copied domains will be connected to the originals with 2 Point Curve connectors.


Guide

19. View, Show Domains

F igure 4.4: Your mesh should appear as th is one af ter complet ing the connector c reat ion.

4.13 More Domains and B lock Creat ion

The rest of the mesh will be created using the automated Assemblecommand. This command’s logic uses specialized topology loop searching algorithms to automatically create domains from selected connectors and blocks from selected and resulting domains. Here you will use Assemble to create each block separately.

1. Ctrl+R (Restores the original orientation of the model.)

2. Use a selection box sized just around the upper domains (AEFG, HLMN) to select the domains and connectors.

3. Click on Assemble Blocks on the toolbar.

The Messages window now reports 5 domains and 1 block created.

4. Use a selection box sized just around the lower domains (BCDE, IJKL) to select the domains and connectors.

5. Click on Assemble Blocks on the toolbar.

The Messages window now reports 3 domains and 1 block created.

With the remaining topology created, you can now move on to setting boundary conditions (BCs) and exporting your CAE and project files.

Use a selection box sized around the two upper domains to select the domains and the connectors used by and connected to the domains:

Then use another sized around the two lower domains:

4.9

Guide

F igure 4.5: The f in i shed mesh i s more c lear ly v iewed with the domains changed to Hidden L ine d i sp lay s ty le .

4.14 BCs and Export

Now create and set boundary conditions on your domains for export to the CGNS solver.

1. CAE, Set Boundary Conditions

2. New

3. Double-click the Name field of the new BC.

4. Enter Inflow.

5. Double-click the Type field of the Inflow BC.

6. Select Inflow.

7. Select the inflow domain (dom-7).

8. Check the Inflow BC. (Assigns selected domain to Inflow BC.)

9. New


11. Enter Outflow.

12. Double-click the Type field of the Outflow BC.

13. Select Outflow.

14. Select the two outflow domains (dom-6, dom-10).

15. Check the Outflow BC. (Assigns selected domains to Outflow BC.)

16. New

Pointwise allows you to set solver specific boundary conditions to export to your chosen CAE solver. For clarity the interior’s of all the symmetry domains and the interfacing domain have been turned off by setting them to Draw Using: Isolines (2x2). Use this image to assist in setting the BC’s:


Guide


18. Enter Wall.

19. Double-click the Type field of the Wall BC.

20. Select Wall.

21. Select the three solid surface domains (dom-5, dom-11, dom-12).

22. Check the Wall BC. (Assigns selected domains to Wall BC.)

23. New


25. Enter Symmetry.

26. Double click the Type field of the Symmetry BC.

27. Select Symmetry Plane.

28. Select all remaining domains.

29. Check the Symmetry BC. (Assigns selected domains to Symmetry BC.)

30. Close

4.15 Save Project

Saving your project file allows you to easily come back and work with your mesh in Pointwise while retaining all previously used groups, layer and display settings. We encourage you to save a project file for every database and/or meshing case on which you work.


2. Save the project file using the standard file browser that appears.

4.16 CAE Export

You can now export your mesh to CGNS and start generating solutions for your application.

1. Select all blocks.


3. Specify the CGNS file using the file browser.

4. Select format options from the Export CAE panel.

5. OK

It is always a good idea to save your grid to a project file early and regularly while working on it. Once saved to a project file, you can quickly save your work as you continue to generate your grid by using the Ctrl+Saccelerator or the Savecommand on the toolbar.

5.1

Chapter 5

Pipe Flange


Guide

5 .1 Overv iew

This section contains a brief overview of generating a 3D volume unstructured grid from an STL database by extracting geometry features from the file. If you have never used Pointwise before, you should work through this and the other tutorials before applying Pointwise to actual problems.

5.2 Commands

In Table 5.1, you will find a display of the most commonly used toolbar commands for this tutorial. Feel free to reference the table as you work through the following sections.

5.3 Geometry

The geometry to be meshed is a 3D Pipe Flange, shown in Figure 5.1. The flange geometry is provided in STL format and is comprised of triangular facets that form the model.

F igure 5.1: The p ipe f lange she l l geometr y in STL format i s represented by t r iangular facets .



Unstructured

2 Point Curves

Assemble Domains Assemble Blocks

Initialize

Save


Reference (Table 5.1) at the beginning of each tutorial. It shows the major toolbar commands used in that tutorial along with the commands’ associated buttons.

5.3

Guide

5.4 Topology

Since you will be meshing the interior volume of the pipe flange, the surface meshes created based on the faceted geometry will form the topology. This surface mesh topology will then be filled with an unstructured volume.

5.5 CAE Se lect ion



2. CGNS

3. OK


5.6 Database Import

The geometry you will use for this example is in an STL file named PipeFlange.stl. It is located in your Pointwise installation directory in the /tutorials/PipeFlange directory. You may want to copy it to a local directory before importing it into Pointwise.


2. Select PipeFlange.stl from the file browser.

3. Open

When importing STL files, you will be presented with a Shell Split Angleoption so that you can split the shell into smaller pieces on import. Since you are not familiar with this geometry, or the angle necessary to split it as needed, go ahead and import it with the angle set to 0, which is the default value. This means that no splitting will occur. You can find a Shell Split Angle that works for the geometry in the Edit Extract feature later in this tutorial and use that angle on input for subsequent work.

4. OK

When dealing with STL data, your topology choices need to be based on the features and their boundaries that you can extract from the original shell.

If your shell entity has no sharp edges to extract, the topology may have to be created by projecting connectors onto the shell or by intersections.


Guide

Orient the view in the Display window as shown in Figure 5.2. You should have imported a single shell database entity made up of faceted triangles defining the flange's geometric shape.

F igure 5.2: The STL f i le imported conta ins one she l l database ent i ty which descr ibes the ent i re geometr y.

5.7 Sett ing Defaul ts

Before you begin constructing your grid, you will need to set a number of default parameters that will be applied to all of the new connectors and unstructured domains you create.

1. Defaults



4. 1.0

Setting the average Δs default ensures that all newly created connectors will be assigned a number of grid points whose average spacing is equal to 1.0.

5.8 Feature Extract ion

The database will first be modified by splitting the shell entity into smaller entities that will make feature meshing easier. Then Pointwise's Domains On DB Entities command will be applied to generate the surface grids. You are now going to use the Extract command to extract geometry from the shell.

1. Select shell-1.

2. Edit, Extract

If you have an unstructured grid with no reference database, you can import the unstructured surface grids in STL format as a database. This will give you a set of database entities on which you can create new or different grids.

5.5

Guide

3. Enter 45 degrees for Split Angle.

4. Uncheck Curves in the Extract frame.

5. Extract

6. OK

You should now have eight shell entities that describe the pipe flange geometry. In Figure 5.3, the resulting database shell display has been changed to a shaded representation with a different color for each shell. To make your database look similar:


2. View, Attributes

3. Click on Apply Rainbow Colors.

4. Click on the Shaded option for Fill.

5. Update Entity Display

6. Close

F igure 5.3: The she l l ent i t ies resul t ing f rom the Ext ract command can be seen shaded in d i f ferent co lors .

As you can see, changing the display attributes in this manner allows you to more easily see that the original shell entity was split wherever the bending angle between adjacent facets exceeded 45 degrees.

5.9 Creat ing Domains

Now that you have shells defining the surface regions that need to be meshed, you can use the Domains on Database Entities command to quickly create domains on those shells.


2. Click Unstructured on the toolbar.

When extracting shells, a good initial split angle to try is 45 degrees. However, you may have to adjust this angle higher or lower and extract again to achieve your desired result.


Guide

3. Click on the Domains on Database Entities icon on the toolbar.

You should now have eight unstructured domains that correspond to your shell entities. To make the domains easier to view, go ahead and turn off the display of the database entities.

4. Uncheck View, Show Database.

In Figure 5.4 you can see the surface domains that were created. Your domains should look similar.

F igure 5.4: The Domains on Database Ent i t ies command automat ica l l y c reated surface domains d i rect ly on the she l l ent i t ies .

5.10 Creat ing B locks

Now that you have surface domains that define the closed volume of the part, you can create the block which makes up the interior volume of the pipe flange.


2. Assemble Blocks

3. Select the block just created.

4. Click Initialize on the toolbar.

You have now successfully created the block and populated it with interior points and you may Examine it if you wish.

5.11 Examine

It is important to evaluate the quality of your mesh prior to exporting it to your CAE. You should use the Examine feature to look at the physical characteristics of your grid and any diagnostic functions important to your solver’s performance.

The Domains on DatabaseEntities command allows the user to shortcut creation of connectors and the domain assembly procedure by producing domains on all database entities using a single command. If you need more control over how the domains are created, try using the Create, On Database Entities or Create, Assemble Special commands.

5.7

Guide


2. Examine, Maximum Included Angle

3. Click on the Cuts tab.

4. Check Enable Cutting.

5. Click the X radio button.

The resulting cutting plane and cells should appear similar to those seen in Figure 5.5.

F igure 5.5: An X cutt ing p lane in Examine a l lows the ce l l s touch ing the p lane to be d isp layed and shaded by the Max imum Inc luded Angle d iagnost ic funct ion.

The user may orient the figure according to their preference. The cut can be marched through the block by using the arrow buttons in the Cut panel or the arrow keys on your keyboard. Cuts such as this one can give you an immediate visual cue to problems in your mesh.

The cells shown in this particular cut are shaded according to the Maximum Included Angle diagnostic function. This function is a measure of cell skewness and is a good indicator of grid quality for unstructured grid

Cutting for the Examinecommand can be done for constant X, Y, and Z planes, or for constant I, J, K indices for structured grids. Make sure you drag your cut through your mesh during examination to get an overall feel for potential problem areas.


Guide

volumes. As a rule of thumb, most solvers do not like for this value to exceed approximately 170 degrees as tetrahedrals with such a high value would be relatively flat. This maximum allowed value can fluctuate however, depending on the solver. Since the maximum angle for this grid is approximately 146 degrees, your mesh should be well within normal bounds.

Now that your examination is complete, you can exit the command.

6. Close

5.12 Save Project

Saving your project file allows you to easily come back and work with your mesh in Pointwise while retaining all previously used layer and display settings. You are encouraged to save a project file for every database and/or meshing case on which you work.


2. Export the project file using the standard file browser that appears.

5.13 CAE Export

You can now export your mesh to your CAE solver and start generating solutions for your application.





5. OK

When specifying a filename for export to your CAE solver, realize that this filename will be used for all export files associated with your solver. You may wish to familiarize yourself with what files to expect.

6.1

Chapter 6

Pipe In A Cube


Guide

6 .1 Overv iew

This section contains a brief overview of generating a basic 3D unstructured mesh within Pointwise. If you have never used Pointwise before, you should work through this and the other tutorials before applying Pointwise to actual problems.

6.2 Commands


6.3 Geometry

The geometry you will be meshing is a 3D cube volume with a pipe intersecting it. The two opposing sides of the volume that are perpendicular to the pipe are an inlet and outlet, respectively. The simulation planned for this mesh is a study of the effects of flow both over the pipe and through it.

F igure 6.1: The geometr y invo lves f low moving through the vo lume as wel l as through the p ipe .



Unstructured

2 Point Curves

Assemble Domains Assemble Blocks

Initialize

Save



6.3

Guide

6.4 Topology

Each of the two fluid regions, inside and outside the pipe, is meshed using two blocks: a prism block near the wall and an unstructured tetrahedral block outside the boundary layer region.

F igure 6.2: The topology used for th is geometr y accounts for the f low condi t ions that wi l l be seen around and through the p ipe.

6.5 CAE Solver Se lect ion



2. CGNS

3. OK


6.6 Database Import

The geometry you will use for this example is in an IGES file named PipeInACube.igs. It is located in your Pointwise installation directory in the /tutorials/PipeInACube/ directory. You may want to copy it to a local directory before importing it into Pointwise.


2. Select PipeInACube.igs from the file browser.

3. Open

The CGNS format (http://www.cgns.org/), a CFD data standard, is really useful for cases where you need to get your grid data into a format you can use for your own in-house solver. Publicly available, the format is supported by many mainstream CFD software packages.


Guide

4. OK

6.7 Defaults

Before you begin constructing your grid, you will need to set an average grid spacing which will be applied to all of the new connectors you create.

1. Defaults



4. 1.5

6.8 Outer Surface Domain Creat ion

The Domains on Database Entities command will be used to create domains quickly on most of our geometry surfaces.

1. Select the four surfaces defining the cube and not intersected by the pipe.

2. Click on Unstructured on the toolbar.

3. Click on the Domains on Database Entities command on the toolbar.

6.9 P ipe Surface Domain Creat ion

The pipe surfaces will require a finer resolution than the domains used on the outer volume surfaces. With that in mind, you will need to change the default average grid spacing for new connectors, then create the pipe surface domains.

1. Defaults

2. Make sure Average Δs is still toggled on.

3. 0.5

4. Select the two pipe database surfaces.

5. Click on the Domains on Database Entities command on the toolbar.

Your surface domains should look like those seen in Figure 6.3. They are now ready for boundary layer block creation.

This diagram illustrates the surfaces (shaded in pink) which define the cube but do not intersect the pipe surfaces. Domains will be created on these surfaces using the Domains on Database Entitiescommand.

6.5

Guide

F igure 6.3: The completed p ipe sur face domains are now ready for use in ext rus ion.

6.10 Boundary Layer B lock Creat ion

A prism mesh needs to exist both within and outside the pipe walls to represent the boundary layer region of flow through and over the pipe. To create this mesh quickly, you can use Pointwise’s algebraic extrusion method to march the pipe’s unstructured surface meshes into two separate prism blocks.

1. Select the two pipe surface domains.


3. Click on the Normal, Boundary Conditions tab.

4. Select the two circular connectors on each end of the pipe. (Four total selected connectors.)

5. Select Type: Constant Z

6. Set Boundary Condition




10. Enter 1.2 for Growth Rate.

11. Check the Orientation Frame.

12. Press Flip if the marching vectors do not point into the region between the pipe and the outer walls of the cube.



15. Run

16. OK (blk-1 is saved.)

The diagram below shows the the pipe surface domains and the circular connectors on the pipe ends.


Guide

The prism block external to the pipe has now been created. Now you will need to create the prism block internal to the pipe based on the same surface domains.



3. Select the two circular connectors on each end of the pipe. (Four total selected connectors.)

4. Select Type: Constant Z



7. Enter 0.05 for Initial Δs .



10. Click Flip if the marching vectors do not point into the interior of the pipe.



13. Run


The prism blocks seen in Figure 6.4 have had their domains’ Display Fil l set to Hidden Line in the Attributes command for easier viewing. However, your extruded blocks should look similar.

F igure 6.4: The ext ruded b locks in and about the p ipe wi l l prov ide addi t iona l reso lut ion for the boundary layer reg ion.

Now that these prism blocks have been created, the volumes inside and outside of the pipe can be meshed with unstructured tetrahedral blocks.

Any unstructured domain containing one or more holes, like the side domain seen below, will have to be assembled using the Create, Assemble Special command. This is due to the fact that the closed loop of connectors describing a hole in a domain are seen as an additional edge whose orientation must oppose that of the first edge.

6.7

Guide

6 .11 Unstructured Domain Assembly

To close the remaining volumes, four unstructured domains will need to be created by hand. Two of the domains will be circular and will close off the remaining volume within the pipe. The other two domains will contain a hole for the boundary layer blocks and close off the larger cube-shape volume outside of the pipe.

1. Select the two circular connectors that define the inner volume on one end of the pipe.

2. Select the two circular connectors defining the pipe inner volume on the opposite end of the pipe.

3. Assemble Domains (The two circular domains are saved.)

4. Create, Assemble Special, Domain

5. Select the four connectors that form a square in one of the open ends of the cube-shaped volume.

6. Next Edge

7. Select the two outermost circular connectors for the final front of the outer boundary layer block.

These connectors should lie in the same plane as those in the previous step.

8. Click Reverse Edge if the orientation of the second edge is not opposite to that of the first edge.

9. Apply (dom-21 is saved.)

10. Select the four connectors that form a square in the remaining open end of the cube-shaped volume.

11. Next Edge

12. Select the two outermost circular connectors for the outer boundary layer block.

These connectors should lie in the same plane as those in the previous step.

13. Click Reverse Edge if the orientation of the second edge is not opposite to that of the first edge.


Now that all volumes in the mesh are closed, the two tetrahedral blocks can be created and initialized.

6.12 Unstructured B lock Creat ion and In i t ia l i zat ion

Creation of the remaining two blocks can be accomplished by assembling their constituent domains into watertight volumes.

For most cases, you can just select all domains and use the Assemble Blocks command to create as many blocks as possible out of the selections. For this mesh though, two blocks have already been created through extrusion. Creating the last two blocks in this case will be faster if their constituent faces are selected by hand and used with Assemble Blocks.


Guide

1. Select the four domains that comprise the closed inner pipe volume.

2. Assemble Blocks (blk-3 is saved.)

3. Select the domains that create a closed volume about the outer boundary layer block.


5. Select the two new blocks.

6. Initial ize

Now that all of your blocks have been created and are populated by cells, you are ready to save your project to a file and to your CAE solver.

6.13 Save Project

Saving your project file allows you to easily come back and work with your mesh in Pointwise while retaining all previously used groups, layer and display settings. We encourage you to save a project file for every database and/or meshing case on which you work.



6.14 CAE Export

You can now export your mesh to your CAE solver and start generating solutions for your application.





5. OK

When exporting your grid to a CAE package, it is always important to select the blocks you wish to export first. The Ctrl+A accelerator can be used to easily select all of the blocks.

7.1

Chapter 7

Boeing 747 Nacelle


Guide

7 .1 Overv iew

This section contains a brief overview of constructing a 3D hybrid mesh within Pointwise. If you have never used Pointwise before, you should work through this and the other tutorials before applying Pointwise to actual problems.

7.2 Commands


7.3 Geometry

The geometry to be meshed is the interior of a Boeing 747 Nacelle. For simplicity, you will not be modeling the engine or the mounting hardware for the nacelle. The portion of the geometry that we are using consists of a central hub and a nacelle.

F igure 7.1: The areas of interes t in the geometr y are the inter ior of the nace l le and the centerbody.



Unstructured

Domains on Database Entities

2 Point Curves

Assemble Domains

Assemble Blocks

Initialize

Save

All Masks On/Off



7.3

Guide

Since this geometry is symmetric about a vertical plane, only half the geometry is included. You will only construct a mesh for this half-symmetry model. If a full mesh is required, for instance for a yawed case, the half-symmetry mesh can easily be copied and mirrored after completion.

7.4 Topology

The hybrid topology to be used will consist of three blocks: an unstructured prism boundary layer block off the centerbody, an unstructured prism boundary layer off the interior of the nacelle, and an unstructured block in the remainder of the volume.

7.5 CAE Se lect ion



2. ANSYS FLUENT

3. OK

You should see the name of your currently selected CAE solver, ANSYS FLUENT, in the left hand corner of the Pointwise status bar.

7.6 Database Import

The geometry you will use for this example is in an IGES file named 747.igs. It is located in your Pointwise installation directory in the /tutorials/B747/directory. You may want to copy it to a local directory before importing it into Pointwise.


2. Select 747.igs from the file browser.

3. Open

4. OK

7.7 F i le Propert ies

To ensure that Pointwise automatically grids over gaps in the database by removing any coincident connectors, you will need to change the connector tolerance to a higher value than the default.

1. File, Properties

When deciding which topology to use for a geometry there are several factors you have to take into consideration: how much time you have available for the grid generation process, the grid types your solver supports, the accuracy desired in certain areas of your grid, and the desired grid size.


Guide

2. Enter 0.02 for the Connector tolerance.

3. OK

Note that the change to the connector tolerance automatically increased the node tolerance as well. The node tolerance may not be less than the connector tolerance.

7.8 Defaults

Before you begin constructing your grid, you will need to set an average grid spacing which will be applied to all of the new connectors you create.

1. Defaults



4. 1.5

7.9 Database Modif i cat ion

The geometry, as imported in the file, contains some entities and pieces of geometry that you will not be meshing in this tutorial. Before you proceed with meshing, you will need to clean up the geometry to get these extraneous surfaces out of the way.

1. Layers

2. Toggle off Layer 38.

Turning off this layer restricts all entities within it from being selected by removing them from the List panel and by not showing them in the Display window.

3. Select the upper foremost surface on the nacelle (747_new-B-SURF-33).

4. Edit, Split

5. Make sure the Advanced frame is checked.

6. Enter 0.75 0.0 for UV.

7. Toggle on U in the Split Direction frame.

8. OK (The database surface is split.)

9. Select the lower foremost surface on the nacelle (747_new-B-SURF-29).

10. Edit, Split

11. Select the split just created on the upper nacelle surface.

12. OK

It is quite common to have a geometry file in which not all curves or surfaces are parameterized alike. As an example, when splitting the two database surfaces at the front of the nacelle, even though they are split in the same physical location, their U values for the split differ. In this case, the U parameterization of the second surface is opposite that of the first surface.

7.5

Guide

Notice that this splits the lower surface at the same location. Now the unneeded geometry ahead of the split can be added to the layer you just turned off.

13. Select the two small database surfaces that were just split off the front of the nacelle.

14. Layers

15. Enter 38 for Layer Number in the Assign Layer frame.

Assigning the two database surfaces to layer 38 (which is currently off) removes the display of the two surfaces from the Display window and the List panel. You are now ready to begin creating surface domains for the modified geometry.

7.10 Surface Domain Creat ion

The Domains on Database Entities command will be used to create domains quickly on most of your geometry surfaces.


2. Click on Unstructured on the toolbar.


In Figure 7.2, you can see an exploded view of the surface domains where their display style has been set to Fill, Shaded and Lines, All Lines in the View, Attributes command for easier viewing. Your domains should look similar.

F igure 7.2: The domains exp loded into the i r separate components : nace l le (green) and centerbody (orange) .

In the diagram below, the two small database surfaces shown need to be reassigned to layer 38 to remove their display from the project workspace.


Guide

7 .11 Boundary Layer B lock Creat ion

You will need to create a prism mesh within the nacelle and outside the nacelle centerbody to represent the boundary layer regions of the flow through the nacelle. To create this mesh quickly, you can use Pointwise’s algebraic extrusion method to march the unstructured surface meshes into prism blocks. The Guide to the left can be used as reference for the steps below.

1. Select the five nacelle surface domains.



4. Select the nacelle connectors color-coded in red.

5. Select Type: Constant Y.


7. Select the nacelle connectors color-coded in blue and pink.

8. Select Type: Constant X.







15. Press Flip if the marching vectors do not point into the region between the nacelle and centerbody.



18. Run


The prism block for the interior wall of the nacelle has now been created. To create a similar block on the nacelle centerbody, you will need to select the centerbody surface domains.

1. Select the two centerbody surface domains.



4. Select the centerbody connectors color-coded in red.



7. Select the centerbody connector color-coded in blue.

This diagram illustrates the boundary conditions (BCs) and the connectors on which they should be applied for the nacelle and centerbody extrusions.

7.7

Guide

8. Select Type: Constant X .






14. Press Flip if the marching vectors do not point into the region between the nacelle and centerbody.



17. Run


The prism blocks seen in Figure 7.3 have been reoriented and the domain display style has been set to Fil l , Shaded and Lines, All Lines in the View, Attributes command for easier viewing. However, your extruded blocks should look similar.

F igure 7.3: The ext ruded b locks with in the nace l le wi l l prov ide addi t iona l reso lut ion for the boundary layer reg ion.

Now that these blocks have been defined, you can close the remaining volume within the nacelle and create a block.

7.12 Remaining Connector and Domain Creat ion

To close the nacelle volume, you will need to create three connectors to form the topology necessary for construction of the last three domains.


The last three connectors created will close off the topology at the inlet and outlet.


Guide


3. Select Points A and B. (con-62 is saved.)

4. Select Points C and D. (con-63 is saved.)

5. Select Points E and F. (con-64 is saved.)

6. OK

Now you can create the three unstructured domains that will close the nacelle interior volume. Two of the domains will represent the inlet and outlet of the volume. The last domain will lie on the nacelle symmetry plane. The connectors these domains will be based upon can be seen in Figure 7.4.

F igure 7.4: The in le t , out let , and symmetr y domain connectors are shown co lor-coded above for eas ier connector se lect ion.

1. Select the closed loop of three connectors that define the inlet. These connectors can be seen highlighted in orange in Figure 7.4.

2. Select the closed loop of four connectors that define the outlet. These connectors can be seen highlighted in pink in Figure 7.4.

3. Assemble Domains (Inlet and outlet domains are saved.)

4. Select the closed loop of thirteen connectors that define the symmetry plane. These connectors can be seen highlighted in red in Figure 7.4.

5. Assemble Domains (Symmetry domain is saved.)

Now that the last volume in the mesh is closed, you can create a block from it and populate it with tetrahedra via initialization.

7.13 Unstructured B lock Creat ion and In i t ia l i zat ion

Creation of the remaining block can be accomplished by assembling its constituent domains into a watertight volume.

In an effort to minimize memory usage, Pointwise does not automatically compute the interior volume grid when an unstructured block is created. Initializing the block will populate it with cells which will then be retained in memory until the block is re-initialized or emptied.

7.9

Guide



This sets the Pick Mask so that only domains will be selectable from the Display window.

3. Click Angle Limit on the toolbar and enter 45.0.

4. Select the large domain on the front of the nacelle extrusion (dom-17).

5. Select, All Adjacent.

This quickly selects all the domains that are topologically connected with a bending angle of less than 45 degrees along the final front of the nacelle extrusion.

6. Select the domain on the front of the centerbody extrusion at the nose (dom-28).

7. Select, All Adjacent

This quickly selects all the domains that are topologically connected with a bending angle of less than 45 degrees along the final front of the centerbody extrusion.

8. Select the inlet, outlet, and symmetry domains created in Section 7.12.


10. Check the Blocks mask.


12. Initial ize

F igure 7.5: The nace l le pr i sm block, centerbody pr i sm b lock, and inter ior tet rahedra l b lock in the f in i shed gr id are d isp layed above in green, orange, and b lue, respect ive ly.

When creating an unstructured volume block about, or in between extrusions (as seen in this tutorial), it is important that domains in the unstructured block’s face are selected from the outermost domains on the extruded block(s). This ensures that the new volume grid you create does not overlap the existing extruded block.


Guide

With some minor changes to the domains’ display attributes, the finished mesh should look similar to Figure 7.5.

Now that all of your blocks have been created and populated with cells, you are ready to move on to setting up the boundary conditions for your mesh.

7.14 Set Boundary Condit ions

Prior to exporting your finished grid, set up the boundary conditions that you plan to use in your CAE solver. Setting these boundary conditions now will make it easier for you to identify regions in your grid once it is imported into your solver. You should find the color-coded version of your grid and its associated boundary conditions (BCs) in Figure 7.6 to be a handy reference during this process.


2. Click New.


4. Enter Inlet.

5. Double-click the Type field of the Inlet BC.

6. Select Inlet Vent.

7. Select the three inlet domains color-coded in green.

8. Check the Inlet BC. (Assigns selected domains to Inlet BC.)

9. Click New.


11. Enter Outlet.

12. Double-click the Type field of the Outlet BC.

13. Select Outlet Vent.

14. Select the three outlet domains color-coded in yellow.

15. Check the Outlet BC. (Assigns selected domains to Outlet BC.)

16. Click New.


18. Enter Wall.


20. Select Wall.

21. Select all nacelle and centerbody domains color-coded in blue.


23. Click New.


25. Enter Symmetry.

If you ever need to change a group of domains assigned to one boundary condition to another, click on the boundary condition, then click Add to Selection in the Set BC panel, and check the new BC to which they should be assigned.

7.11

Guide

26. Double-click the Type field of the Symmetry BC.

27. Select Symmetry.

28. Select the eleven symmetry domains color-coded in red.

29. Check the Symmetry BC. (Assigns selected domains to Symmetry BC.)

30. Close

F igure 7.6: The boundary condi t ions and the i r cor responding domains can be seen in these color-coded representat ions of the back and f ront of the f in i shed nace l le gr id.

All boundary conditions have now been assigned to your grid. You can proceed to export the project and CAE solver files.

7.15 Save Pro ject




It is always a good idea to save your grid to a project file early and regularly while working on it. Once saved to a project file, you can quickly save your work as you continue to generate your grid by using the Ctrl+Saccelerator or the Savecommand on the toolbar.


Guide

7 .16 CAE Export

You can now export your mesh to ANSYS FLUENT and start generating solutions for your application.



3. Save the ANSYS FLUENT file using the file browser.

If you are running your grid through multiple CAE solvers, Pointwise makes it easy to transition your grid. Just go to CAE, Select Solver, and select a new solver. Next, go to the CAE, Set Boundary Conditionscommand and set the Type for each Boundary Condition to the appropriate equivalent for your new solver.

8.1

Chapter 8

Transition Duct


Guide

8 .1 Overv iew

This section contains a brief overview of constructing a 3D multiblock, structured mesh within Pointwise. If you have never used Pointwise before, you should work through this and the other tutorials before applying Pointwise to actual problems.

8.2 Commands


8.3 Geometry

The geometry to be meshed is the interior of a duct whose cross-sectional shape transitions from a circle to a rectangle. Since this geometry is symmetric about a vertical plane, only half the geometry is included.

F igure 8.1: The duct geometr y cons i s ts of two database surfaces in which the cross-sect ion t rans i t ions f rom a c i rcu lar to a rectangular shape.



All Masks On/Off

Spacing

Constraints Mask

Structured Start Solve

Spacing Attributes

Stop Solve

Assemble Domains

2 Point Curves

Save

Assemble Blocks



8.3

Guide

8.4 Topology

The topology to be used will consist of two blocks: a structured, O-topology boundary layer block off the duct walls and a structured, H-topology block in the remainder of the volume.

F igure 8.2: The boundary layer b lock (green) and the inter ior b lock (ye l low) wi l l be used to reso lve the f low in the boundary layer and main duct reg ions respect ive ly.

8.5 CAE Se lect ion

Before starting a meshing project, it is always a good idea to first select your CAE solver. This helps avoid any situations in which you create a mesh type that is unsupported by your solver.


2. STAR-CD

3. OK

You should see the name of your currently selected CAE solver, STAR-CD, appear in the left hand corner of the Pointwise status bar.

When using an all structured topology for a grid, it is important to remember that structured domains require four edges and structured blocks require six faces to be assembled. For domains, each edge can contain numerous connectors. For blocks, each face can contain numerous domains. The main restriction for domains and blocks is that opposing edges/faces have the same dimensions.


Guide

8 .6 Database Import

The geometry you will use for this example is in an IGES file named TransitionDuct.igs. It is located in your Pointwise installation directory in the /tutorials/TransitionDuct/ directory. You may want to copy it to a local directory before importing it into Pointwise.


2. Select TransitionDuct.igs from the file browser.

3. OK

8.7 Defaults


1. Defaults



4. 50

8.8 Database Modif i cat ion

The geometry contains two database surfaces. You will split each surface in half in the V direction effectively splitting them at the corners of the rectangular cross-section. This will help define the layout of the grid topology that will be created later.

1. Select the surface named Pipe-Upper.

2. Edit, Split

3. Make sure the Advanced frame is checked.


5. Toggle on V in the Split Direction frame.

6. OK

7. Select the surface named Pipe-Lower.

8. Edit , Split


10. OK

You should now have four database surfaces that look similar to those seen in Figure 8.3. These surfaces mimic the topology we will use for the duct surface domains.

These diagrams illustrate the UV location at which both surfaces need to be split.

8.5

Guide

F igure 8.3: The four sur faces that resu l t f rom sp l i t t ing the two or ig ina l sur faces are d i sp layed in d i f ferent co lors in an i sometr ic v iew.

8.9 Surface Domain Creat ion

The Domains on Database Entities command will be used to create domains quickly on your geometry surfaces.


2. Click on Structured on the toolbar.


Due to the default dimension that was specified earlier, you now have all connectors dimensioned to 50. The circumferential connectors describing the inlet and outlet require fewer grid points to accurately resolve the shape of the duct. You will need to quickly redimension these connectors before proceeding further.

1. Select the connectors that describe the circular inlet.

2. Select the connectors that describe the rectangular outlet.

3. Click in Dimension on the toolbar.

4. 25


Spacing constraints within the mesh help control how tightly the grid lines are clustered in certain regions. Since the cell size currently varies at the inlet and outlet, you will need to adjust the spacing constraints there to make it consistent.



3. Select all vertical spacing constraints at Points A, B, C, D, and E.

This diagram illustrates the spacing constraints and values that need to be set at the duct inlet and outlet.


Guide

4. Select all horizontal spacing constraints at Points F, G, H, I, and J.


6. 2.0

F igure 8.4: The domains af ter spac ing const ra ints have been appl ied show cons is tent ce l l s i zes in the in le t and out let reg ions but gr id l ine sp lay ing near the duct e lbow.

8.11 Domain Smoothing

If you look at the surface domains that describe the elbow and the rectangular region of the duct, you can see that there is some splay in the grid lines in the corners. This issue can be resolved by applying an elliptic PDE-based smoothing method to the domains.

1. Check the Domains Mask.


3. Click on Start Solve on the toolbar.

4. Click on Stop Solve once the grid appears to have converged (Figure 8.5).

In Figure 8.5, you can see the domains after elliptic smoothing has been applied. Note that the domains display style has been set to Fil l , Shadedand Lines, All Lines in the Attributes command for easier viewing.

Even though the smoothing applied to the surface domains seems minor, it is actually quite important for several reasons. Without the elliptic smoothing of these domains, the grid in the corners of the rectangular portion of the duct would not accurately capture the shape of the duct. Additionally, the quality of an extrusion relies largely on the quality of the surface grids involved. Improving the grid in these regions will provide an overall higher quality extruded block.

8.7

Guide

F igure 8.5: The smoothed domains show much less gr id l ine sp lay ing in the areas of h igh curvature .

8.12 Boundary Layer B lock Creat ion

A structured block will be created near the duct walls to resolve the boundary layer region. To create this mesh quickly, you can use Pointwise’s hyperbolic extrusion method to march the structured surface domains into a hexahedral block. The Guide to the right should be used as reference for the steps below.



3. Check Assemble Special.

4. Click on Delete All Faces .

5. Toggle on One Face Per Domain in the Assemble frame.

6. Assemble

7. Done


9. Select the four inlet connectors seen color-coded in blue.



This diagram illustrates the connectors that must be selected for setting boundary conditions for the structured block extrusion.


Guide

12. Select the four outlet connectors seen color-coded in yellow.

13. Select Type: Constant Z.


15. Select two symmetry connectors seen color-coded in red.

16. Select Type: Constant X.







23. Press Fl ip if the marching vectors do not point into the interior of the pipe.



26. Run

27. OK (blk-1 , blk-2 , blk-3, and blk-4 are saved.)

Now that these blocks have been created, you can close the remaining volume within the duct and create a block.

8.13 Remain ing Connector and Domain Creat ion

To close the duct volume, you will need to create two connectors to form the topology necessary for construction of the last three domains. You can use the diagram available in the Guide to the left to assist you in creating these connectors.



3. Select Points A and B.

4. Select Points C and D.

5. OK

These two connectors need to have the same dimension as their opposing edge in the structured domains you will be constructing to keep the domains computationally rectangular. Since their opposing edge (comprised of two connectors sharing a node) has a dimension equal to 49, you will need to redimension them to match.

1. Check the Connectors Mask.

2. Select the two connectors just created.

The additional connectors that need to be created to close off the duct volume can be seen in the below diagram labeled and color-coded in red.

8.9

Guide

3. Click in Dimension on the toolbar.

4. 49

Additionally, the spacing constraints on the two new connectors need to be adjusted to closely match the height of the last layer of cells in the boundary layer block. This will ensure a smooth transition between the two blocks.

1. Select both spacing constraints on the two new connectors.


3. 0.05

Now you can create the remaining structured domains that will close off the duct volume. Two of the domains represent the inlet and outlet of the volume (Figure 8.6). The remaining domain lies on the duct symmetry plane.

F igure 8.6: The in let and out let domain connectors are shown co lor-coded above for eas ier connector se lect ion.

1. Select the closed loop of five connectors that define the inlet. These connectors can be seen color-coded in pink in Figure 8.6.

2. Select the closed loop of five connectors that define the outlet. These connectors can be seen color-coded in orange in Figure 8.6.

3. Assemble Domains (dom-11 and dom-18 are saved.)

4. Select the closed loop of four connectors that define the symmetry plane.

5. Assemble Domains (dom-23 is saved.)

To improve the corner cells of the inlet and outlet domain, you should smooth those domains using the elliptic solver.

1. Select the inlet and outlet domains.

2. Click Start Solve on the toolbar.

3. Click Stop Solve on toolbar once large changes to the grid’s smoothness have ceased.

The Assemble Blocks command evaluates every variation of possible domains and/or blocks that could be created from your selections. For large selection sets, assembly will require more time.As an alternative, you may want to consider using a selection box to select just the entities you need assembled. This will ensure that your domains/blocks are assembled as quickly as possible.


Guide

8 .14 Structured B lock Creat ion

Creation of the remaining block can be accomplished by assembling its constituent domains into a watertight volume.



3. Click Angle Limit on the toolbar and enter 45.0.

4. Select one of the four domains on the final front of the extruded block (Example: dom-14).

5. Select, All Adjacent.

6. Select the inlet, outlet, and symmetry domains created in Section 8.13.

7. Assemble Blocks

After changing the display style of the domains to Fil l, Shaded and Lines , All Lines in the Attributes command, the finished mesh should look similar to Figure 8.7.

F igure 8.7: The f in i shed gr id i s d isp layed above in an i sot rop ic v iew with inset v iews of the in let and out le t .

When applying boundary conditions to domains, do not forget to include the side domains from any extrusions that were performed. These domains can be smaller and easily overlooked.

8.11

Guide

Now that all of your blocks have been created, you are ready to move on to setting up the boundary conditions for your mesh.

8.15 Set Boundary Condit ions

Prior to exporting your finished grid, set up the boundary conditions that you plan to use in your CAE solver. These boundary conditions will make it easier for you to identify regions in your grid once it is imported into your solver. You should find the color-coded version of your grid and its associated boundary conditions (BCs) in Figure 8.8 to be a handy reference during this process.


2. Click New.

3. Double-click the Name field of the new BC (bc-2).

4. Enter Inlet.

5. Double-click the Type field of the Inlet BC.

6. Select Inlet.

7. Select the five inlet domains color-coded in pink.

8. Check the Inlet BC. (Assigns selected domains to Inlet BC.)

9. Click New.


11. Enter Outlet.

12. Double-click the Type field of the Outlet BC.

13. Select Outlet.

14. Select the five outlet domains color-coded in yellow.

15. Check the Outlet BC. (Assigns selected domains to Outlet BC.)

16. Click New.


18. Enter Wall.


20. Select Wall.

21. Select all duct surface domains color-coded in green.


23. Click New.


25. Enter Symmetry.

26. Double-click the Type field of the Symmetry BC.

27. Select Symmetry.

Once your boundary conditions (BCs) have been assigned, the BC name, ID, and domain association will be kept in Pointwise regardless of what CAE solver you have selected. However, since the physical types supported by CAE solvers vary, you will need to reset the Physical Type for each BC if you decide to change your CAE solver in Pointwise.


Guide

28. Select all symmetry domains color-coded in blue.

29. Check the Symmetry BC.

30. Close

F igure 8.8: The boundary condi t ions and the i r cor responding domains can be seen in th is co lor-coded representat ion of the f in i shed t rans i t ion duct gr id .

All boundary conditions have now been assigned to your grid. You can proceed to export the project and CAE solver files.

8.16 Save Project




8.17 CAE Export

You can now export your mesh to STAR-CD and start generating solutions for your application.

When exporting files to a CAE solver that has multiple input files, you will only need to specify a filename once. All necessary input files will be exported with that filename and the appropriate extension to the directory you have chosen in your file browser.

8.13

Guide

1. Check the Blocks mask.



4. Save the STAR-CD files using the file browser. The selection of blocks with which you enter the File, Export, CAE command determines exactly which parts of your mesh are exported to your CAE solver. To quickly select all blocks, mask all entity types except blocks, then use the Ctrl+A accelerator.


9.1

Chapter 9

Re-Entry Vehicle


Guide

9 .1 Overv iew

This section contains a brief overview of writing a Glyph script for creating a grid for a reentry vehicle within Pointwise.

Glyph scripting provides an object-oriented, Tcl-based interface to Pointwise commands. It is ideal for creating parameterized scripts such as the one addressed in this tutorial.

If you have never written a complete script before, you should work through this tutorial before using Glyph scripting for actual problems.

If you have never used Tcl before, you may want to review the basics online at: http://www.tcl.tk/doc before starting this tutorial.

9.2 Topology

The topology to be constructed is a quarter symmetry grid created by extruding a structured domain into a 3D block.

F igure 9.1: An O-H topology gr id wi th a po le wi l l be created by s imply assembl ing connectors into a domain then ext rud ing i t into a 3D b lock.

Due to the simplicity of the geometry, no database entities are required to create the mesh.

9.3 Programming Logic

Before starting a scripting project, it is always a good idea to first evaluate what entities you will start with (if any) and your objectives. For this example, you will start with no pre-existing entities and create a structured domain. From the structured domain, you will extrude a 3D block that represents the flowfield around a reentry vehicle.

If you are unsure of the usage and restrictions of a Glyph command, refer to the Glyph man pages at:http://www.pointwise.com/glyph2

9.3

Guide

You need to then determine the meshing procedures for achieving your goal as if you were using the GUI commands. As shown in Figure 9.2, this script will be written following the process outlined below:

F igure 9.2: Determine the main s teps requi red to complete your scr ipt ing pro ject .

For each of these steps, you need to identify the Glyph object types you may want to manipulate and how they relate to each other. For this tutorial, the types that will be used are:

• global types - pw::Grid, pw::Application

• grid entity types - pw::Connector, pw::DomainStructured, pw::BlockExtruded, pw::BlockStructured.

• grid entity support types - pw::Distribution, pw::Edge, pw::FaceStructured

• segment types - pw::SegmentCircle, pw::SegmentConic, pw::SegmentSpline

• mode types - pw::Mode

Once you have determined the actions you want to perform (copy, paste, translate, etc.), search for their syntax information using the above types as the key words. For actions associated with the type pw::Grid, for example, refer to the Glyph man pages at http://www.pointwise.com/glyph2, and search pw::Grid under About, Type.

If database and/or grid files need to be imported within a script, you can use the pw::Database import and/or pw::Grid import command.


Guide

While writing your script, keep in mind that a great script means much more than simply meeting specifications. It has to be efficient and robust. For instance, always construct procedures for similar tasks that can be consolidated. These procedures will streamline your programs as well as facilitate the debugging process. An example of constructing a procedure for connector creation will be introduced later in this tutorial. In addition, make sure you build checks into your scripts to catch and report possible failures. For example, what if a domain fails to be assembled due to gaps between the connectors’ adjacent nodes?

9.4 In i t ia l izat ion

Initializing a Glyph script consists of loading the Pointwise Glyph extensions to the Tcl language and choosing what settings the script starts with.

You can use whatever text editor you like to begin entering the script. We will walk through the script commands below. Tutorial text shown in a Courier New font is what you will type in your text editor.

First, you need to load a suitable version of the required package into the interpreter. This allows the Glyph commands to be called.

1. Begin your script with the following package line which corresponds to Pointwise V16.03:package require PWI_Glyph 2.3

If commands that are exclusive to a higher version are added to this script, you will need to change the package version number to the one used by that version of Pointwise.

Because this script will not depend on any pre-existing entities, you will clear all grid and database entities from memory and reset the defaults, attributes, tolerances, layer settings, and so on.

2. Force all settings to be reset within Pointwise using:pw::Application reset

Now you can define the initial values for user parameters. Refer to Figure 9.3and Table 9.1 for their names and descriptions.

Procedures must be defined before being called. Otherwise, the Tcl interpreter will not be able to recognize the variables defined within the local scope of the procedure. Because of this requirement, usually all the procedures are at the top of the file.

9.5

Guide

F igure 9.3: The gr id boundar ies are formed by l ine, c i rc le , and conic connectors c reated based on predef ined parameters .

As seen in Table 9.1, the variable names are based on physical parameters (such as the nose, cone, shoulder of the vehicle) and the letters used to label the geometry in Figure 9.3.

In practice, variable names should be shortened versions of what the parameter stands for. This makes a script more readable. For example, the variable for the number of the grid points at the nose is named conDimAB. Keep in mind when setting variables names that Tcl is case sensitive.

Table 9.1: User Input Parameters

Variable Name Parameter Description Initial Value

conDimAB Number of grid points on nose 25

conDimBC Number of grid points on cone 37

conDimCD Number of grid points on shoulder 9

conDimDE Number of grid points on shelf 11

conDimEF Number of grid points on OB top 121

dsWall Normal-to-wall spacing 0.001

radiusBase Radius of base 100.0

radiusNose Radius of nose 50.0

radiusShoulder Radius of shoulder 10.0

There are two Glyph actions: instance and static. An instance action is specific to a single object (i.e., $seg). It is called by specifying this object followed by the action and parameters. A static action, however, can only work with a type (i.e., pw::Connector). For example, to create a connector on a database curve, pw::Connector has to be used with createOnDatabase, which is a static command:

set con [pw::Connector createOnDatabase $dbCurve]


Guide

Now that you know the variables that need initialization, use the command set to define them. Their values can be integer, real, string, list, etc. For math expressions, use the expr command to parse and evaluate them, and then define them as variables.

3. Define all constants that will be used in your script:# deg2Rad is used for translating an angle in degrees

# to radians.

set pi [expr {4 * atan(1.0)}]

set deg2Rad [expr {$pi / 180.0}]

4. Define all variables in Table 9.1 in a manner similar to the following examples:set radiusBase 100.0

set conDimAB 25

5. Use Figure 9.3 to define the dimension of connectors GA and FG to ensure a balanced grid:set conDimGA $conDimEF

set conDimFG [ expr $conDimAB + $conDimBC + $conDimCD

+ $conDimDE - 3 ]

Note that the dimension of the connector FG is defined by a math expression.

6. Set the math expressions you will need for this tutorial based on those defined below:set ang [expr {$coneAngle * $deg2Rad}]

set sinConeAngle [expr sin($ang)]

set cosConeAngle [expr cos($ang)]

set ang2 [expr {$ang * 0.5}]

set sinConeAngle2 [expr sin($ang2)]

set cosConeAngle2 [expr cos($ang2)]

shelfLength Length of shelf 15.0

coneAngle Angle of cone 45.0

obStagPtOffset of outer boundary stagnation

point2.0

obTop Offset of outer boundary top 33.0

obRho Rho value of outer boundary conic 0.5

Table 9.1: User Input Parameters

Variable Name Parameter Description Initial Value

For information about Tcl’s supported math functions, refer to the Tcl man page for the mathfunc command. Take Tcl version 8.5 as an example, such information can be found at:http://www.tcl.tk/man/tcl8.5/TclCmd/mathfunc.htm

9.7

Guide

9.5 Def ine Nodes

The nodes A-J need to be defined prior to connector creation. Their coordinates can be obtained by referring to Table 9.2:

Table 9.2: Reference for Nodes Locations

Node Location

A

x_A=x_G + obStagPt

y_A=0

z_A=0

B

x_B=x_A + radiusNose * (1 - sinConeAngle)

y_B=radiusNose * cosConeAngle

z_B=0

C

x_C=x_B + (y_C - y_B) * cosConeAngle / sinConeAngle

y_C=radiusBase - radiusShoulder * (1.0 - cosConeAngle)

z_C=0

D

x_D=x_C + radiusShoulder * sinConeAngle

y_D=radiusBase

z_D=0

E

x_E=x_D + shelfLength

y_E=radiusBase

z_E=0

F

x_F=x_E

y_F=y_E + obTop

z_F=0

G

x_G=0

y_G=0

z_G=0

H

x_H=K0 * y_H^2 + x_G

y_H=(y_G + y_F) * 0.5

z_H=0

K0=( x_F - x_G ) / y_F^2

pw::GridEntity is the base type for all the grid entity types (i.e., pw::Connector, pw::Domain, and pw::Block). Any non-static actions (i.e., transform) you do with pw::GridEntity, you are also allowed to do with its child entities.


Guide

To define the nodes as explicit xyz points, you should use a Tcl list. If a node needs to be defined by a math expression, you can include variable reference and nested commands in the expression.

1. Define the nodes A-J (except H) in a manner similar to the following examples:set G "0 0 0”

set A "[expr [lindex $G 0] + $obStagPt] 0 0"

# Obtain the values of x_B and y_B for the node B.

set x [expr {$radiusNose * (1.0 - $sinConeAngle)}]

set y [expr {$radiusNose * $cosConeAngle}]

set B "[expr {[lindex $A 0] + $x}] $y 0"

To obtain the coordinates of the node H, you need to first calculate the coefficient K0 using the two nodes, F and G.

2. Obtain K0 based on the user defined equation in Table 9.2, K0 =(x_F - x_G) / y_F^2: set x [lindex $F 0]

set y [lindex $F 1]

set K0 [expr {($x - [lindex $G 0]) / ($y * $y)}]

Now you can define the node H in terms of its coordinates.

3. Set the coordinates of the node H based on the equation given in Table 9.2.set y [expr {([lindex $G 1] + [lindex $F 1]) * 0.5}]

set x [expr {$K0 * $y * $y + [lindex $G 0]}]

set H "$x $y 0"


Because connectors are created quite often within mesh generation, you will now write a procedure that creates connectors of three types:

• Line - BC, DE, EF,GA

I

x_I=x_A + radiusNose * (1 - cos(0.5 *deg2Rad * (90 - coneAngle)))

y_I=radiusNose * sin(0.5 * deg2Rad * (90 - coneAngle))

z_I=0

J

x_J=x_C + radiusShoulder * (sinConeAngle - sinConeAngle2)

y_J=radiusBase - radiusShoulder * (1 - cosConeAngle2)

z_J=0

Table 9.2: Reference for Nodes Locations

Node Location

Both double quotes ““ and curly braces {} can be used to group words together into one argument. The difference is that quotes allow substitutions to occur in the group while curly braces do not. This rule applies to commands, variables, etc. For example:

set x 0set G “$x 0 0”set F {$x 0 0}

The variable G will be defined as 0 0 0 and F will become $x 0 0.

9.9

Guide

• Conic - FG

• Circle - CD,AB

The proc command defines a new Tcl procedure. It takes three arguments: the name of the procedure, a list of input parameters for the procedure, and the body of the procedure.

In this procedure, you will include three key factors for defining a connector as the input parameters: segment type (segmentType), dimension (conDim) and control points (args):

1. Begin your procedure with the following lines:# createDimCon --

# Create connector with specified segment type and

# dimension.

# Arguments:

# Segment type, connector dimension and control

# points.

# Results:

# A connector of the given segment type is created

# and dimensioned.

proc createDimCon { segmentType conDim args } {

By default, these variables are local variables within the procedure.

Note that the third parameter, control points, can be a variable number of arguments, which allows for different types of segments. So the key word args will be used rather than a specific name. When this procedure is called, the args parameter will be a list that contains all the remaining values of the argument.

In Glyph, modes are recommended for operations like create, modification, extrusion, etc.

2. Begin the Create mode using:set createCon [pw::Application begin Create]

This mode separates the newly created entities from those already in existence until desired operations have been completed. Once the mode is ended, the newly created entities will be checked against existing entities for duplicates. However, the Create and Modify modes may not be necessary if the changes will only affect the entities on which the operations occur.

Given a value of the parameter segmentType, use the switch command to branch to one of three command bodies for creating LINE, CONIC and CIRCLE connectors. The general format of the switch command is:

switch flags value { pattern1 body1 pattern2 body2 ......}

3. For this tutorial, you will need to match the value exactly to one of the patterns, so use the flag -exact:switch -exact $segmentType {

Each procedure should begin with a procedure header that gives overall documentation for the procedure, followed by the declaration and body of the procedure. The header usually contains three parts: abstract, arguments and results.


Guide

4. If the value of segmentType is LINE, the following command body will be called:Line {

# Create a connector spline segment object. set seg [pw::SegmentSpline create]

# Add control points to the curve segment.

foreach pt $args {

$seg addPoint $pt

}

# Set the slope vector constraint for this segment.

$seg setSlope Linear

# Create a connector object.

set con [pw::Connector create]

# Add segment to the connector.

$con addSegment $seg

}

5. If the value of segmentType is Circle, the following command body will be called:Circle {

set seg [pw::SegmentCircle create]

# Add the first end point. $seg addPoint [lindex $args 0]

# Add the second end point. $seg addPoint [lindex $args 1]

# Setting the shoulder point requires the input of # point coordinates.

$seg setShoulderPoint [lindex $args 2]



}

6. If the value of segmentType is Conic, the following command body will be called:Conic {

set seg [pw::SegmentConic create]

# Add the first end point. $seg addPoint [lindex $args 0]

# Add the second end point. $seg addPoint [lindex $args 1]

# Set the shoulder point via its coordinates. $seg setShoulderPoint [lindex $args 2]



To create a curve segment of one of the types: Akima, Catmull-Rom or Bezier, you need to set the slope to Akima, CatumllRom or Free within pw::SegmentSpline.

9.11

Guide

}}

Once the operations within this mode are completed, you need to make sure the mode is ended properly. Otherwise, the opened mode in your script will cause Pointwise to be aborted when it is executed.

7. As soon as the connector is created, end the Create mode using the following command:$createCon end

8. Now you need to specify the dimension of the connector you just created by the value of the parameter conDim:$con setDimension $conDim

9. Then return the created connector as the result of the procedure.return $con

}

Once this procedure is defined, it can be called by specifying its three arguments (segmentType, conDim, args) in order.

10. Call this procedure to create connectors of different types:set con_AB [createDimCon Circle $conDimAB $A $B $I]

set con_BC [createDimCon Line $conDimBC $B $C]

set con_CD [createDimCon Circle $conDimCD $C $D $J]

set con_DE [createDimCon Line $conDimDE $D $E]

set con_EF [createDimCon Line $conDimEF $E $F]

set con_FG [createDimCon Conic $conDimFG $G $F $H]

set con_GA [createDimCon Line $conDimGA $G $A]

9.7 Adjust ing Connector Dis tr ibut ion

For grid lines to be clustered in certain regions, spacing constraints within the mesh need to be adjusted. Connector distribution functions will also need to be adjusted for constructing good quality domains.

For this grid, you will set the beginning spacings of EF and GA to the wall spacing. This ensures the domain that will be created in the next section clusters towards the wall region, ABCDE.

1. To change the spacing of EF, you need to define a distribution object of its first subconnector. set subconDist [$con_EF getDistribution 1]

The getDistribution command returns a pw::Distribution object that represents the first subconnector of EF.

2. Then set the beginning spacing of this object to dsWall:$subconDist setBeginSpacing $dsWall

The distribution function of the connector FG can also be set by using break points. You need to first determine the locations of the break points based on where the points B, C and D are along ABCDE. Then adjust the dimensions of the resultant subconnectors. This allows you to adjust the spacing constraints at the break points.


Guide

Note that the location of the beginning spacing will be determined by the orientation of this subconnector.

3. Set the ending spacing of GA using the same approach except that setEndSpacing has to be used rather than setBeginSpacing.

The two edges FG and ABCDE will be used as the opposite edges to construct a structured domain in Section 9.8. Therefore, the distribution of FG needs to be set based on the connector distributions of AB, BC, CD and DE.

4. Create a general distribution function object from a list of subconnectors of the reference connectors: AB, BC, CD and DE:set generalDistFG [pw::DistributionGeneral create \

[list [list $con_AB 1] [list $con_BC 1] \

[list $con_CD 1] [list $con_DE 1] ]]

For single segment connectors (i.e., AB, BC, CD and DE), the subconnector index of each list element above is 1.

Once the general distribution function of FG is defined, you will apply this function to FG using the setDistribution command.

5. Set the distribution function of FG:$con_FG setDistribution 1 $generalDistFG

The setDistribution command takes two arguments: the index of the target subconnector ([1, number of subconnectors]) and the distribution object that will be applied. Since the connector FG has one single subconnector, the index becomes 1.


With all the connectors created and refined, you are now ready to assemble them into four edges of a structured domain: AE, EF, FG and GA.

Many errors, such as gaps between connector nodes, can cause the domain assembly process to fail. If uncaught, such errors will abort execution of the script. In this tutorial, you will use the catch command to catch errors and report them. This command takes two arguments:

catch command ?resultVar?

The first argument is a command body (i.e., domain assembly commands). The second argument is the name of a variable that will contain the result of the command, or an error message if the command raises an error. The catchcommand returns zero if there is no error caught, or a non-zero error code if it does catch an error.

1. Use the catch command to trap errors that may occur within the domain assembly process:if { [catch {

Note that you should use curly braces to group the commands within the command body.

When the catch command is used, the global variables, errorCode and errorInfo are set to describe the error. You will want to print out their values sometimes for debugging an error.

9.13

Guide

2. Define the edge AE by adding the multiple connectors, AB, BC, CD and DE, consecutively:# Define an edge object.

set edge_AE [pw::Edge create]

# Add connectors to the edge.

$edge_AE addConnector $con_AB

$edge_AE addConnector $con_BC

$edge_AE addConnector $con_CD

$edge_AE addConnector $con_DE

3. Create the other 3 edges: EF, FG and GA in a manner similar to the following example:set edge_EF [pw::Edge create]

$edge_EF addConnector $con_EF

4. Prior to assembling these edges into a domain, create a structured domain object:set dom_A [pw::DomainStructured create]

5. Using a foreach control loop, you will add the four edges you just created in order for domain assembly.foreach edge "$edge_AE $edge_EF $edge_FG $edge_GA" {

$dom_A addEdge $edge

}

6. Now you will complete the error catching process by adding error handling:} result] } {

# Print out a message if an error is raised.

puts "Domain failed to be assembled."

} else {

# Domain assembly was successful.

}

9.9 So lve Domain

To improve the smoothness, clustering and orthogonality of the domain you just created, you will need to apply the elliptic solver.

1. Begin the elliptic solver mode using the following line:set solveDom [pw::Application begin EllipticSolver $dom_A]

Any attributes that are different than the default need to be specified.

2. Set the angle blending function of the domain’s 3rd edge to Linear:$dom_A setEllipticSolverAttribute -edge 3 \

To solve a group of domains with the same attributes, you may want to use a collection as a shortcut. A collection is a type for a group of entities with the same or mixed types. It can be used to work on several entities at once.

set domCol [pw::Collection create]$domCol set [pw::Grid getAll -type pw::Domain]$domCol do setDefault InteriorControl Laplaceset solveDoms [pw::Application begin EllipticSolver [$domCol list]]$solverDoms run 60$solveDoms end


Guide

EdgeAngleBlend Linear

3. Then you will run the solver for 20 iterations:$solveDom run 20

4. Make sure you end the EllipticSolver mode after the domain is solved:$solveDom end

9.10 Extrude Block

Using the domain you just constructed, a block will be created via rotational extrusion. The rotational extrusion will need to march 90 degrees about the connector AG.

1. First, create a structured block object:set blk_A [pw::BlockStructured create]

2. Before you begin extruding the block, define your initial front (the domain you just created) as the first face of the block:set face_1 [pw::FaceStructured createFromDomains $dom_A]

# Add this face as the first face of the block.

$blk_A addFace $face_1

3. Begin the ExtrusionSolver mode that is required for creating an extruded block:set extrudeBlk [pw::Application begin \

ExtrusionSolver $blk_A]

4. Define the extrusion mode, rotation axis, and specify the rotation degree:$blk_A setExtrusionSolverAttribute Mode Rotate

$blk_A setExtrusionSolverAttribute RotateAxisStart $A

$blk_A setExtrusionSolverAttribute RotateAxisEnd $G

$blk_A setExtrusionSolverAttribute RotateAngle 90

5. Now you will extrude the block for 20 steps.$extrudeBlk run 20

6. Keep in mind that you have to end the ExtrusionSolver mode once the block is created:$extrudeBlk end

9.11 Export Gr id

Now that your grid is completed, you will export it into a PLOT3D file.

1. Define the directory where your script is saved:

If a block face is formed by multiple domains, you need to replace $dom_A with a list of these domains, $domList:

set face_1 [pw::FaceStructured createFromDomains $domList]

Pointwise will try different combinations of assembling the domains together. So you don’t have to worry about the domain order within this list.

To assemble structured blocks with complex face topology, you will want to use another method which is more predictable:

set face_1 [pw::FaceStructured create]$face_1 addDomain $dom_A$face_1 addDomain $dom_B$face_1 addDomain $dom_H

9.15

Guide

set scriptDir [file dirname [info script]]

This allows the output file(s) to be saved in the directory where your script is located.

2. Now export the block you just created to a PLOT3D file named reentryVeh.x:pw::Grid export -type PLOT3D $blk_A [file join \

$scriptDir "reentryVeh.x"]

9.12 Execute Your Scr ipt

Once your script is completed, save it using your text editor with the name reentryVehicle.glf. Then execute your script via:

1. Script, Execute

2. Select your script from the file browser.

3. Open

You can also execute your script in batch by typing in the following at the command line (Linux):

$pwi_home_path/pointwise -b $script_path/reentryVehicle.glf

where pwi_home_path refers to the Pointwise installation directory, and script_path refers to the directory where reentryVehicle.glf is located. Refer to Section 1.1 of the Glyph Reference Manual for instructions on how to execute a script in batch on other platforms (i.e., Windows 32 bit, Mac OSX, etc.).

To re-execute a script, you can use either the Re-Execute command in the Script menu, or the hot keys (i.e., Ctrl+E for Windows systems).

A common debugging technique is printing the value of variables or lines to be evaluated. For a script that runs for a long time, you may want to write debugging information into a log file instead of to the screen:

set log [open [file join $scriptDir my.log a]puts $log “Debug info xxxxx”close $log


Chapter 10

Index

10.2 Pointwise User Manual

Numerics

2 Point Connectors 4-32 Pt Connector 4-7, 7-72 Pt Connectors 3-10, 8-82D Mesh 4-23D Mesh 3-2, 4-2, 6-2, 7-2, 8-2

A

Airfoil 1-2Assemble Blocks 4-8, 6-7, 7-8, 8-10Assemble Domains 6-7, 7-8, 8-9Assemble Special

Domain 6-7Attributes

Database 2-7Average Grid Spacing 1-4

B

Backward Step 4-3Block Assembly 4-8, 8-10Boeing 747

Centerbody 2-3Nacelle 2-3, 7-2

Boundary ConditionsName 4-9, 4-10, 7-10, 8-11New 4-9, 4-10, 7-10, 8-11Type 4-9, 4-10, 7-10, 8-11

Boundary Layer 3-9, 6-3, 6-5, 7-6, 8-7

C

CAECGNS 4-3, 4-10, 6-3, 6-8Fluent 7-3, 7-12Set BCs 4-9, 7-10, 8-11Solver 3-3, 4-3, 6-3, 7-3, 8-3, 9-

4STAR-CD 3-3, 3-11, 8-3, 8-12

ConnectorCreate 1-4Dimension 1-4Display 1-4

Connectors on Database Entities 1-4

Create2 Pt Connector 7-72 Pt Connectors 3-10, 8-8Assemble Special 6-7Block 6-7Blocks 4-8, 7-8, 8-10Connector 4-7Domain 4-5, 9-11Domains 7-8, 8-9Domains on Database Entities 3-5,

6-4, 7-5, 8-5Extrude 4-5, 6-5, 7-6, 8-7, 9-11Intersect 2-9Planes 2-9

Cube 6-2

D

DatabaseAttributes 2-7Display 2-7Import 3-3, 7-3, 8-4Intersect 2-9Planes 2-9

Database Import 1-3, 2-3, 6-3Defaults 3-4, 4-3, 4-6, 6-4, 7-4, 8-4

Average Grid Spacing 6-4, 7-4Connector Dimension 1-4, 3-4,

4-3, 4-6, 8-4Dimension 8-5, 8-9Domains on Database Entities 3-5, 6-4, 7-5, 8-5Duct 3-2, 8-2

E

EditCopy 4-6Split 7-4, 8-4Transform 4-6Translate 4-6

Entity Selection 2-4, 2-6Export

CAE 3-11, 4-10, 6-8, 7-12, 8-12

ExtrudeBoundary Condition 6-5Boundary Conditions 7-6, 8-7

Domain 1-5, 4-5, 9-11Flip Orientation 7-6, 7-7Geometric Growth Factor 6-6, 7-

6, 8-8Initial spacing 7-6, 8-8Normal 6-5, 7-6, 8-7Total Steps 6-6, 7-6, 8-8

Extruded 2D Mesh 1-2

F

FileExport 4-10, 6-8Properties 7-3

G

GridDimension 8-5, 8-9Initialize 4-6Solver 3-8, 4-6, 6-7, 7-9, 8-6, 8-

9Spacing 4-4, 8-6, 8-9

H

H-grid 8-3H-topology 8-3Hybrid 7-2

I

IGES 1-3IGES Import 3-3, 6-3, 7-3, 8-4Import

Database 3-3, 7-3, 8-4IGES 2-3IGES File 1-3

Import, Database 6-3Initialize 6-7, 7-9

L

LayerAssign 2-4, 2-5, 7-5Description 2-5, 2-9Isolate 2-6, 2-7Off 2-8

Layer Description 2-6Layer Manager

10.3

Database Organization 2-2Layer Sets 2-8

Description 2-8Restore 2-10Save 2-8

LayersAll On 2-7Current 2-9Show Empty Layers 2-9

M

Mesh Dimension2D 1-2

N

NACA 6412 1-2

O

O-grid 1-2, 8-3O-topology 1-2, 8-3

P

Pipe 6-2Prism Block 6-5

S

SaveProject 1-6, 3-10, 4-10, 6-8, 7-

11, 8-12Selection Mask

All On/Off 4-4, 8-5Connectors 4-5Domains 3-8, 4-6, 8-6Spacing Constraints 1-5, 4-4, 8-5

Spacing 4-4, 8-6, 8-9Spacing Constraints 1-5, 4-4, 4-5Start Solve 8-9Start Solver 3-8, 8-6Stop Solve 8-9Stop Solver 3-8, 8-6Structured 3-2, 4-2, 8-2Structured 2D Mesh 1-2

T

ToleranceConnector 7-3

U

Unstructured 6-2, 6-7, 7-3, 7-8

10.4 Pointwise User Manual

Pointwise_TutorialWorkbook

Documents

glyph man

guidethis

graphical

maximum extent

left hand

start generating

provide additional

pointwise