ANSYS AQWA for Hydrodynamic Analysis UK/staticassets/RM...• China Ship Classification Society ... • Stability including mooring lines ... Excel interface

ANSYS AQWA ANSYS AQWA forfor

Hydrodynamic Hydrodynamic AnalysisAnalysis

ANSYS AQWA ANSYS AQWA forfor

Hydrodynamic Hydrodynamic AnalysisAnalysis

Richard MayRichard MayRichard MayRichard May

© 2010 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary© 2011 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

Richard MayRichard May

AQWA DevelopmentAQWA Development

ANSYS HorshamANSYS Horsham

Richard MayRichard May

AQWA DevelopmentAQWA Development

ANSYS HorshamANSYS Horsham

What is AQWA?

•AQWA is a modularised, fully integrated hydrodynamics analysis suite based around 3-D diffraction/radiation methods.

© 2010 ANSYS, Inc. All rights reserved. 2 ANSYS, Inc. Proprietary

diffraction/radiation methods.

History of AQWA

• Developed since 1971 (by WS Atkins)

• Owned and developed by Century Dynamics since

2001

• Century Dynamics acquired by ANSYS February 2005


• Century Dynamics acquired by ANSYS February 2005

• Now being integrated into the ANSYS Workbench

system

Some Clients

Regulatory Bodies

• ABS (US)

• Lloyds Register (UK)

• Germanischer Lloyd

• China Ship Classification Society


• China Ship Classification Society

• RINA (Italy)

Some Clients

• US Navy

• SBM Monaco

• SBM Atlantia

• Allseas

• Dockwise

• Friede & Goldman

• INTEC

• Arup Energy

• Alion

• Atkins


• Dockwise

• Huismann Itrec

• VUYK

• Technip

• WorleyParsons

• GustoMSC

• REpower

• AMOG

• D2M

• Moffatt & Nichol

• Noble Denton

• Han Padron

• Krylov Institute

• VersaMarine

ANSYS AQWA - Capabilities

• Diffraction and Radiation including Morison elements

• Frequency domain analysis

• Stability including mooring lines

• Time domain with irregular waves

• Time domain with non-linear survival waves


• Time domain with non-linear survival waves

• Coupled cable dynamics

• Multiple hydrodynamic interaction and articulations (up to

50 structures)

• Transfer of motions and pressures to ANSYS FE models

ANSYS AQWA - Applications

• Determination of RAOs

• Wave bending moments

• Splitting force calculations for semi-submersibles

• Design and analysis of mooring systems

• Time history of motions


• Time history of motions

• Determination of air gaps

• Calculation of shielding effects of ships and barriers

• Multiple-body interactions

• Coupled mooring line-structure interaction

• Cable dynamics with intermediate buoys

• TLP tether analysis

Modelling in AQWA - elements

• Diffracting or non-

diffracting panels

• Morison elements

– TUBE

– STUB


– STUB

– DISC

• Point masses

• Mixed models

Modelling in AQWA - connections

• Moorings

– Linear springs

– Elastic catenaries

– Intermediate buoys

– Tethers

– Pulleys


– Pulleys

• Fenders

• Articulations

• Stiffness matrix

Modelling in AQWA - environment

• Waves

– Regular / irregular

– Time history

• Current

• Wave Spectra

– Pierson-Moskowitz

– JONSWAP

– Gaussian

– User-defined


– Uniform

– Profile

• Wind

– Uniform

– Spectra

– Time history

– Cross-swell

• New for 14.0

– Multiple simultaneous spectra

– Interaction between spectra

from different directions

Radiation / Diffraction

• Multiple structures including

hydrodynamic interaction

• Hydrodynamic coefficients

(added mass and damping)

• RAOs

• Drift coefficients (Near / far field,


• Drift coefficients (Near / far field,

full QTF matrix)

• Shear Force / Bending Moment

• Splitting forces

• Pressure distribution for

transfer to FE

• New for v14.0

– Linearised tube dragVideo\Ship&Box.avi

Load Transfer

• Calculation and transfer of hydrodynamic loads to ANSYS for structural analysis


AQWA Pressure plot

ANSYS Pressure plotImages courtesy of Vuyk

Engineering Rotterdam

Equilibrium and Stability

• Computes static

equilibrium position for

multiple environmental

and mooring

configurations


• Preliminary mooring

design

• Calculates static /

dynamic stability

• Video\Librium.avi

Frequency Domain

• Significant motions at low frequency and/or wave frequency

• Permits rapid analysis using linearisedparameters of mooring


parameters of mooring systems

• Graphs for response spectra / RAOs & other parameters

• Wave spreading and 2D spectra

Time-history

• Time-history analysis of multiple structures with regular or irregular waves

• Convolution of radiation forces

• Can use full QTF matrix for shallow water conditions


shallow water conditions

• Import of wave height time history

• Input of forces via user-defined dll

• Output of motions and forces

• Graphical and animation results

Time-history animation


Cable Dynamics

• Additional cost item for

more rigorous

simulation of mooring

line behaviour

• Provides full coupled


• Provides full coupled

vessel/mooring line

analyses

• Included in all modules

except AQWA-LINE

Excel interface

• AQWA specific functions add-in for Excel for

data and results retrieval, processing and

report generation


Traditional Graphical Interface

• Automatic mesh generation

from lines plans

• Results presentation

• Graphical manipulation of

results


results

• Export to spreadsheet

• Function processing e.g.

Nodal RAOs

Fourier transforms

• Model checking

Hydrodynamics in Workbench

• Hydrodynamic Diffraction and Hydrodynamic

Time Response represent an ANSYS

Workbench implementation of the ANSYS

AQWA hydrodynamic software

• Provides a common look and feel across the


• Provides a common look and feel across the

ANSYS product suite

• Provides for future interoperability with other

physical models in the ANSYS product suite,

e.g., ANSYS Mechanical and ANSYS CFD

The ANSYS Workbench

simulation process

ANSYS

DesignModelerCAD

ANSYS

Hydrodynamic

Diffraction

ANSYS

Hydrodynamic

Time Response




Surface and Pressure Plots

• Animated Surface Plots


Model definition


Results Graphs



• What it currently provides (Release 14.0):

– Import of geometry from ANSYS DesignModeler

– Interactive data modification and editing

– Native meshing


– Diffraction/radiation analysis

– Definition of moorings, fenders and joints

– Definition of environment

– Graph plotting

– Wave surface and pressure contour plots

Key Differentiators

• Integrated (diffraction/radiation, time & frequency

domain, regular & irregular waves,)

• Full hydrodynamic interaction

• Ability to add .DLL with external forces (e.g. DP

system)


• Up to fifty connected structures

• Integration into ANSYS Workbench

• Modelling flexibility

• Coupled cable dynamics

• Proven over 30 years of use

• Ability to transfer pressures and motions to Finite

element analysis

ANSYS AQWA

The end


Thank you

ANSYS AQWA for Hydrodynamic Analysis UK/staticassets/RM...• China Ship Classification Society ... • Stability including mooring lines ... Excel interface

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