Top Banner
1 | Page Semi-Span Flapping Wing Model ME 435 Project Design and Management II Brayler Gonzalez, Julia Romanchik & Bryce Horvath 4/26/2011
14

Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Mar 11, 2020

Download

Documents

dariahiddleston
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

1 | P a g e

Semi-Span Flapping Wing Model

ME 435 Project Design and Management II

Brayler Gonzalez, Julia Romanchik & Bryce Horvath

4/26/2011

Page 2: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page 2

Contents:

List of Figures: .............................................................................................................................................. 3

Abstract: ........................................................................................................................................................ 4

Introduction: .................................................................................................................................................. 5

Wing Design and Wind Tunnel Assembly: .................................................................................................. 6

Inventor Model.......................................................................................................................................... 6

Materials ................................................................................................................................................... 7

Wing Mechanism ...................................................................................................................................... 7

Wing Characteristics ................................................................................................................................. 8

PIV ............................................................................................................................................................ 8

Force Transducer ...................................................................................................................................... 9

List of Materials ...................................................................................................................................... 10

Overall Wing Mechanism Set-Up ........................................................................................................... 11

Wind Tunnel ........................................................................................................................................... 12

Cost Consideration Summary: .................................................................................................................... 12

Scheduling: ................................................................................................................................................. 13

Future .......................................................................................................................................................... 13

References: .................................................................................................................................................. 14

Page 3: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page 3

List of Figures:

Figure 1 – Inventor Model of Wing ……………………………………………………………6

Figure 2 – Inventor Model of T-Connecter …………………………………………………….6

Figure 3 – Wing Mechanism …………………………………………………………………...7

Figure 4 – Particle Image Velocimetry ………………………………………………………...8

Figure 5 – Force Transducer …………………………………………………………………....9

Figure 6 – List of Materials ……………………………………………………………………10

Figure 7 – Wing Mechanism Set-up …………………………………………………………...11

Figure 8 – Layout of ODU's low Low-Speed wind tunnel …………………………………….12

Figure 9 – Gantt Chart …………………………………………………………………………13

Page 4: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page 4

Abstract:

The Semi-Span Flapping Wing project’s main objectives include obtaining a force

analysis and determining the flow field around a single flapping wing in order to demonstrate the

aerodynamics surrounding the wing due to both vertical flapping motion and varying angles of

attack. The wing utilizes a design which causes it to aeroelastically bend while flapping due to

spar rotation in conjunction with a turn table, allowing for both the vertical flapping motion,

bending motion, and varying angles of attack, imitating bird flight (Rabiger). This project

employs the use of the low speed wind tunnel, as well as a force transducer and particle image

velocimetry to measure the desired properties. The resulting data will give insight to the multiple

aerodynamic occurrences surrounding the wing model for further use in designing more efficient

and effective flapping wings.

Page 5: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page 5

Introduction:

Flapping Wing Flight refers to flight driven by oscillating airfoils which imitate nature.

This includes flapping wing flight as seen in insects, bats, and birds. Currently, ornithopters are

the most popular form of flapping wing aircraft (Chronister, 1996), but research progression has

expanded the range of flapping wing aircraft to include multiple devices with various uses, and

has evolved from simple toy models to flapping UAVs for use in spy missions. Our research

objective includes obtaining information on flapping wing motion in bird flight, bird anatomy

and skeletal structure, and past and present flapping wing projects. This information, in

conjunction with some assumptions and simplifications due to the complexity of bird flight, will

allow us to determine a plausible and testable wing design. Using this design, we will construct a

simplified kinematic wing structure mechanism using Inventor software. After calculating the

theoretical forces expected to act on the wing during flapping flight, we will determine possible

materials which contain necessary properties to obtain vertical and torsional flapping motion and

build the model for use in testing in the low speed wind tunnel. Through this experiment, we

hope to be able to better apprehend flapping flight for future use in aircraft, since little

information on how or why flapping flight works is currently available. The data collected in this

experiment would allow for a better understanding of the air flow and forces acting on the wing,

which could be used to improve the design to produce a more efficient flapping wing for use in

aircraft.

Page 6: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page 6

Wing Design and Wind Tunnel Assembly:

Inventor Model

Figure 1 Inventor Model of Wing

Figure 2 Inventor Model of T-Connecters

Note: The first four

T-connecters are

exactly

perpendicular. The

following four T-

connecters are

angled, with the

angle increasing per

connecter towards

the tip of the wing.

H1 (Rigid Spar)

H2

(Bending

Spar)

Ribs Ripstop Nylon

Ribs

H1

(Rigid

Spar)

Page 7: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page 7

Materials

The spars H1 and H2 and the ribs will be carbon fiber rods, with the rigid spar H1

constructed from a larger diameter rod to promote rigidity, and the bending spar H2 made up of a

smaller diameter rod to promote flexion. The ribs will attach to the rigid member by means of the

T-Connectors as seen on Figure 2. The surface membrane of the wing will be Ripstop Nylon,

allowing the wing to bend naturally. The Ripstop Nylon membrane will be attached to the rods

using sewn in pockets around the ribs and spars, in combination with glue, if necessary. A DC

current motor with a specially made encoder will be used to create the flapping motion.

Figure 3 Wing Mechanism

Wing Mechanism

The figure above shows that the motor will generate the flapping motion by rotating the two

connected links and shaft, which is connected to spar H1by a connector pin. When the wing

completes a cycle, going from a downstroke to an upstroke and back down to a downstroke, the

resulting motion produces one wing beat. Each wing beat cycle, measured in Hertz, can be

manipulated and controlled by using an encoder. Our highest upstroke angle is 23 degrees and

our lowest downstroke angle is 23 degrees (Bullen, & McKenzie, 2002), based on our research

of bird flight. Spar H2 rotates the wing passively as the mechanism moves the rigid spar,

producing torsion without requiring any direct input from the motor. In other words, H1 acts as a

rigid bar or a bending resistant spar that transmits the power, while H2 is free to elastically twist

due to torsion, making it twist naturally with maximum torsion occurring at the tip of the wing

(Rabiger). The encoder will give Labview the motor's position with respect to time. It should be

noted that the entire moving mechanism sits on top of the force transducer to precisely measure

all forces.

Connector Pin

DC Motor

Shaft

Links

H1

Force

Transducer

Page 8: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page 8

Wing Characteristics

Table 1 Wing characteristics

Wing Semi-Span 1.5 ft

Wing Area of Semi-Span .807 ft2

Aspect Ratio of the Span 5.577

Wingbeat Frequency 5 Hz

With a uniform flow of 10 m/s and an angle of attack of 5 degrees applied to the Semi-Span

Wing, and using the NACA 0012 2-D Lift Coefficient (Abbott, &Von Doenhoff, 1959) the

results turnout to be:

Table 2 Lift and Drag Parameters

Lift .4166 lbs

Drag .0153 lbs

L/D 27.28

PIV

A particle image velocimetry system will be used to

measure the velocity of the flow stream around the

wing. The particle image velocimetry system consists

of a high quality digital camera, a laser, and a fiber

optics cable that synchronizes the instruments together

by an external trigger that fires the laser and the camera.

It contains an optical arrangement to covert the laser

output light into a thin light sheet, which measures the

instantaneous velocity at a 2 dimensional slice of the flow field. After multiple fires from both

the laser and camera, we will have a sufficient number of instantaneous flow fields to compile

them into a video clip. This clip will show how the flow moves around the wing, turbulent spots,

separation of flow, and vortices generated by the wing.

Figure 4 Particle Image Velocimetry

Layout (Kerenyi, 2007)

(Hennington, Spedding, & Hedenstrom, 2008)

These numbers were calculated assuming the Elliptic-Spanwise

Circulation Distribution for the Lifting Line Theory (Bertin, &

Cummings, 2009)

Page 9: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page 9

Force Transducer

A force transducer will be used to measure the forces acting on the wing. A table of the

measureable forces is illustrated below. The device converts force, weight and pressure into

output signals. These signals are then sent to a data acquisition system

on a computer. The measurements from the force transducer, the PIV

system, and the position of the DC motor will be combined in Labview

to give a full analysis of the forces acting on wing at different points in

time.

Table 3 Max Load and Accuracy of the Force Transducer

Fx,Fy Fz Tx,Ty Tz

Max

Load

±280 lbf ±930 lbf ±700 lbf-in ±730 lbf-in

Accuracy 1/160 lbf 1/80 lbf 1/80 lbf-in 1/80 lbf-in

Figure 5 Force

Transducer

Page 10: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page

10

List of Materials

Cost Amount in a Pack

Needed Amount

Total

Mechanism

Keyed Shaft $20.00 1 1 $20.00

Key Stock (3/32" x 12") $1.50 1 1 $1.50

Sleeve Bearing (for Shaft) $0.53 1 2 $1.06

Shaft Collars (ID - 3/8") $2.17 1 5 $10.85

Shaft Collars (ID - .25" $2.03 1 3 $6.09

Dowel Pins (D - .25") $9.85 50 1 $9.85

Sleeve Bearing (Thrust Washer)(.25") $1.84 1 4 $7.36

Sleeve Bearing (Thrust Washer)(3/8") $2.24 1 2 $4.48

Socket cap Screws (M4x16mm) $7.69 25 1 $7.69

Socket cap Screws (M6x25mm) $6.62 25 1 $6.62

Washers (for a M6 Screw - OD 9.9mm) $8.65 50 1 $8.65

Socket cap Screws (M6x16mm) $8.00 100 1 $8

Motor 27:1 Planetary $49.99 1 1 $49.99

H1 (Rigid Member) 32.5L - .252OD - .154ID $6.18 1 1 $6.18

H2 (Twisting Member) 29.5L - .179OD - .102ID $4.36 1 1 $4.36

Ribs 48L - CR.098in - W 7.53g $4.49 1 2 $8.98

Ripstop Nylon $11.95 1 1 $11.95

Reed Switch $0.61 1 3 $1.83

Figure 6: List of Materials

Page 11: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page

11

Overall Wing Mechanism Set-Up

Figure 7 Wing Mechanism Set-up

This assembly consists of a bottom plate with a force transducer on top of spacer plate, followed

by another rectangular plate that has the two side plates, where the DC gear motor is mounted.

The DC motor powers two links; an upper and a lower link. The upper link is connected to a

shaft which has a connector pin in the middle where the H1 member is attached. This rigid

member (H1) powers the entire wing. The motor has a torque of 694 oz-in and a max rpm value

of 300, which is more than enough to oscillate the wing. The connection between the motor and

the shaft consists of: a wheel connector, a dowel pin, a thrust washer, a link, another thrust

washer, a shaft collar, then another dowel pin that connects the two links, a thrust washer and a

shaft collar on each side. The shaft the link is connected to it by a square key, followed by a

thrust washer and a sleeve bearing, and on the other side, there is a thrust washer and a shaft

collar. The whole assembly will be mounted on a turntable to allow easy and rapid modification

to the angle of attack. This will enable easy comparison of performance at different angles of

attack to help optimize results. The top plate's top surface sits flush to the wind tunnel and will

be bolted down to the turntable.

H1 Side Plates

Upper &

Lower Link

Shaft

Dowel Pin

Shaft

Collar

Thrust

Washer

Wheel

Connector

Motor

Bottom

Plate

Top Plate

Rectangular

Plate

Force

Transducer

Spacer

Page 12: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page

12

Wind Tunnel

Figure 8 Layout of ODU's low Low-Speed wind tunnel

This is a schematic of the ODU's subsonic wind tunnel. It is a closed loop wind tunnel with the

necessary turning vanes to redirect the flow, as well as honeycombs and screens to achieve a

uniform flow by the time it reaches our model. Our model is located at the teal ellipse, which is

the high speed test section which measures 3 by 4 feet.

Cost Consideration Summary:

Dr. Landman is providing funding for the project. The only direct costs come from the

cost of carbon fiber rods, Ripstop Nylon fabric, the motor, and the mechanism. All machining

will be done in ODU's machine shop at no cost to us. ODU already owns the force transducer,

turntable, and PIV equipment.

1) Motor: $50

2) Wing: $60

3) Mechanism Components: $95

Total: $205

Old Dominion University

Department of Aerospace Engineering

Low-Speed Wind Tunnel

Dimensions in Inches

High Speed Test Section

(3” X 4’ X 8’ long)

Low Speed Test Section (9’ X 8’)

Fan

Diffuser

Diffuser

Flow

Flow

Turning VanesWing Model Location

Located in KH Room 143

Low Speed Test SectionHigh Speed Test Section

Page 13: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page

13

Scheduling:

Gantt Chart

Figure 9 Gantt Chart

The research phase began on October 21st and was completed on November 22nd, with the

selection of the flapping motion that was to be modeled. After this, we selected the wing design

which promotes aeroelastic twisting by spar rotation. Then, we constructed an Inventor model to

get an idea of the flapping angle and to see how everything would fit together. Soon after, we

assembled a prototype wing made out of kite material, wood and fiberglass. During this time we

completed the technical drawings and the part selection for the mechanism. The machine shop

has finished the parts and the parts have come in enabling us to assemble our mechanism.

However, our mechanism cannot be complete without the force transducer which we won't be

able to get a hold of till mid May, along with the wind tunnel. Therefore, we are taking our time

applying the ripstop nylon to our skeletal structure of the wing. The ripstop nylon is cut out and

will be sown around the rigid spar and the ribs in the near future.

Future

Because of the encroaching end to the semester and the lack of wind tunnel time, we will

continue working on the project through the summer. The remaining tasks include: setting up

the tachometer in Labview using input from the reed switch, integrating the force transducer in

LabVIEW, and testing the wing in the wind tunnel.

Page 14: Semi-Span Flapping Wing Modeld2oqb2vjj999su.cloudfront.net/users/000/082/618/962... · 2013-12-03 · Semi-Span Flapping Wing Model ME 435 Project Design and Management II ... aerodynamic

Page

14

References:

Abbot t , I r a , & Von Doenhoff , Alber t . (1959) . Theory o f wing sect ions . New

York: Dover .

Ber t in , John, & Cummings , Russel l . (2009) .Aerodynamics for engineers .

Upper Saddle River : Pearson Educat ion .

Bu l l en , R . , & M cKenz ie , N . ( 20 02 ) . Sca l i n g b a t wi n gbea t f r equ en c y an d

am pl i tu de . Th e Jour na l o f E xp er i m en ta l B i o lo g y , 2 3 . R e t r i ev ed f ro m

h t t p : / / j eb .b i o l o g i s t s .o r g / cg i / co n t en t / fu l l / 20 5 / 17 / 26 15

C h ro n i s t e r , N a t h an . (1 99 6 ) . Th e o rn i th o p t er z on e . R e t r i ev ed f r om

h t t p : / / w w w. or n i th op t e r .o r g /

H en n in g t on , P , S p ed d i n g , G , & Hed ens t rom , A . (2 00 8 ) . V o r t ex w ak e an d

f l i gh t k in em at i cs o f a s wi f t i n c ru i s i ng f l i gh t i n a win d tu n ne l . Th e

Jo ur na l o f E xp er i men ta l B io lo g y , 2 11 . R e t r i ev ed f ro m

h t t p : / / j eb .b i o l o g i s t s .o r g / cg i / co n t en t / ab s t r ac t / 21 1 / 5 /7 17

K e r en yi , K o rn e l . (A r t i s t ) . ( 20 07 ) . E xp er i m en ta l s e t u p fo r pa r t i c l e i m ag e

v e l oc im e t r y . [ W eb] . R e t r i ev ed f r om

h t t p : / / w w w. fh w a .do t . go v / en g i n eer in g /h yd r au l i c s / r es ea rch / md do t . c fm

R äb i ge r , Ho r s t . (n .d . ) . Oth er f l a pp in g w in g d es ig ns . R e t r i ev ed f r om

h t t p : / / o rn i th op t e r .de / en gl i s h / win gs .h tm