Fluid id-Stru ructure re I Intera raction on i in STAR-CC - - PowerPoint PPT Presentation

Fluid id-Stru ructure re I Intera raction

• n i

in STAR-CC CCM+ Alan M Muelle ller CD CD-ada adapc pco

What at is F is FSI SI?

Air Interac action wit ith a a Flexible Struc uctur ture

What at is F is FSI SI?

Water/Air I Interac actio ion with a a Structure Courtesy Germanischer Lloyd Courtesy CFD Marine

What at is F is FSI SI?

Vortex Induced V Vib ibrat ation an and Gal allo loping

What at is F is FSI SI?

Aeroelas astic F Flutter

What at is F is FSI SI?

Hyd Hydroplan aning

What at is F is FSI SI?

Gulp ulping ng Courtesy Tetra Pak

What at is F is FSI SI?

Ask 20 en engi gineers “What is FSI SI?” and d you will likely ge get 2 20 di different answers There is not simply one ap approac ach v valid alid for al all FSI problems The an anal alyst must be presented wit ith a a ran ange of options an and chose the most suitab able le

The U Uniq ique Ch Chal allenges o

• f FSI

SI Sim Simulations

Protocols a and format ats f for exchan anging data – Getting data from Code A to Code B Map Mappin ing dat ata a between n non-conforma mal m mes eshes es – Finding neighbors and interpolating Coupling methods – Algorithms for accuracy, stability, efficiency Dynam amic ic fluid mesh evolu lutio ion – Topology changes in the fluid domain Valid alidat ation of F FSI r result lts 9

VOF f for

• r fre

free s surface t tra ransient flo flow Overs rset mesh shes f s for m motio ion an and d deformat matio ion Fluid i id interactio ion wit with

– multi-body rigid structures – compliant structures

Co Co-Simula lation b between d differe rent C CAE c codes Mappi apping b between n non-conformal mal m mesh shes Para ralle llel s l scalabili lity o

• n compute c

cluster Enabli ling t techn hnolog

• logies t

to m meet t the c challe lenges

Simu mulat atio ion o

• f Store S

Separ arat atio ion

DFBI – Fluid interac action wit ith a a Rig Rigid id B Body Over erset Tec echnology

Simu mulat atio ion o

• f Lifeboat

at L Launchin ing

Overset grids allow simulation of launching

• f various devices

(lifeboats, missiles etc.). VOF OF for f free s surfac ace tran ansient flo low DFBI – Fluid interac action wit ith a a Rig Rigid id B Body Over erset Tec echnology

Th The Ch Challenges o

• f FSI

MAPPIN PPING

The he 3 3 st steps ps of “

• f “Ma

Mapping”

Sea earch ching f for op

• pposing nei

neighbo bors

– Most of the computer time

Interpola

• lating s

source s stencil d l data on

• n a target p

point

– Source and targets may be face or vertex

Often r en requi uires es i int nteg egration ( (quadratu ture res) – intensive extensive variables – pressure force – heat flux heat – FEA nodal loads: integration of intensive variables against the shape function.

Neighb hbor S

• r Search I

h Impera rative

Sear arch r requir ires l lit ittle user in intervention The search e excludes potential al neighbors based on proximity y and o

• rientat

atio ion Critic ically y importan ant for s sheet metal al parts

– resolve ambiguities of poor geometry – thin solid parts may be on the wrong side of the fluid surface

Par aral alle lel Map Mappin ing is is a a must!

– Takes advantage of distributed memory

Courtesy of Daimler

Mappi apping D Disp isplac acement f for Low Y w Y+ me meshes

C0 continuous mapping very important for low y+ meshes Otherwise very easy for morpher to invert high aspect ratio cells in prism layer

Inconsist sistent G Geome metric ic R Repr prese sentat atio ions

FEA VIEW of a WING CFD VIEW of a WING

Beam to Surface Mapping

?

Shells(no mass,stiffness) Beam elements Kinematic Couples

Th The Ch Challenges o

• f FSI

DATA E A EXCH CHANG ANGE

18 18

Metho hods f for E Excha hanging Data S STA TAR-CC CCM+/CA CAE File B Based T d Transf sfer: I Import/Map/E ap/Expo xport

– Data exchange via files on a hard-disk – CAE code need not be resident in memory – Often called “Loose Coupling” – User responsible for exchange synchronization

So Socket Base Based T Transfer: Co Co-Sim Simulat atio ion A API – API controls exchange synchronization – Data exchanged via sockets

– CAE code and STAR-CCM+ both executing in memory

• STAR-CCM+ to STAR-CCM+ Co-simulation
• STAR-CCM+ to 1D external Codes

–GT Power, Wave, Olga, AMESim, Relap5

• STAR-CCM+ to Abaqus Co-Simulation using Abaqus API

STA TAR-CCM+ : : Loosely Co Coupl pled CA CAE Su Suppo pport

Import CAE CAE Me Mesh: h:

– Abaqus, Nastran, Ansys, STAR-CCM+ – RadTherm, es-ice

Map & Expor

• rt R

Resu sults t s to

• CAE

– Surface Loads

• Pressure, Shear Traction
• Heat flux or Temperature
• Heat Transfer Coeff, Ambient Temp

– Volume Loads

• Temperature
• Heat Source

Im Import & & Map ap FE FEA R Res esul ults

– Temperature Fluid Wall BC – Displacement, Eigenmodes Morpher

import from/export to the native CAE format Display mapped results on imported mesh

STA TAR-CCM+ can an p provide an an im import/map ap/export servic ice as as a a powerful complement nt to HEED EEDS

Heeds: W : Work rkflo low P Process C Control

• l

22 22

Abaqus/STAR-CCM CCM+ C Co-Simula lation

Co Coupling v via ia Ab Abaqu qus Co Co-Sim Simulat atio ion A API o

• f SIMULIA

– Manages Coupling Synchronization/Exchange/Mapping – Abaqus v6.13/STAR-CCM+ v8.04+ (implicit coupling) – Surface to Surface Mapping STA TAR-CCM CM+ A Abaqus s (expl xplic icit it or stan andar dard) d) – Pressure – Shear traction – Surface HTC, Tref Ab Abaqu qus STA TAR-CCM CCM+ – Displacement, velocity – Temperature

Overset Ball and Socket Stop Valve Hydroplaning

Strateg egy : : Coup uple S STAR-CCM CCM+ to Abaqus

– Implicit Coupled on workstation

STAR-CCM+ V Vor

• rtex Induced F

Flo low a arou

• und Fle

lexible le P Pipe Aba baqus F FEA EA for

• r Flexibl

ble e Pi Pipe

Flexible le r riser ( r (L/D = = 50) in turb rbule lent crossflo flow.

Riser cross sec ection

Riser er di dimen ension

• ns:

L = 3.8125 m, D = 76.25 mm T = 7.05 mm

Current ent:

Vin = 1.2 m/s Re(D) = 81700 Struc uctur ural al Material al P Proper perties es: Young’s Modulus= 1.5 GPa; Poisson ratio = 0.42; density = 8563 kg/m3;

Co Coupled So d Solution : : Disp isplac acement an and d Vortic icit ity

z/L=0. 0.25 25 z/L /L=0.5 .5

The C Challe llenges of F FSI

Co Coup uplin ing T g Tech echniq nique

Degre rees o

• f Coupli

ling

Two-way ay coupl pling for

• r f

fluid-ela lastic e c equilibrium

– Steady-state flow over static structure deformed by fluid loads

One ne-way dy dynamic c c coupl pling

– Loads only go from fluid to structure – Loads only go from structure to fluid

Two-way dy dynamic c coupli pling

– Explicit (exchange loads once per time step)

• Unstable for relatively light and/or compliant structure interacting with heavy,

incompressible fluid

• Interest in physics with time scales which are long compared to acoustic time scales

– Implicit (exchange loads more than once per time step)

Th The Ch Challenges o

• f FSI

Val alid idat atio ions

Exp xperimental V Val alid idation: W Wedg dge D Drop I p In Wat ater

Comparison of E Experime ments and d Model dels Pet eter erson, Wyma man, and Frank: “ “Dr Drop Tes ests t to Su Support W Water-Impac act an and Pl Planing Boat D Dynami mics Theo eory”, ”, D Dahlgr gren en Division N Naval Surface e Warfare e Cen enter, C CSS/ SS/TR-97/25 STA TAR-CCM+ VOF with differen ent bodi dies es

– Rigid Body (6DOF, DFBI) – Elastic Body (FV stress) – Elastic Body (Abaqus Co-Simulation) – Elastic Body (FE Stress)

Wedg dge D Drop I p In Wat ater

Vertical acceleration Angular acceleration (rad/s2) Equivalent Stress (MPa) All Methods give good agreement to experiments

AeroElast astic ic Predic dictio ion Work rksho hop: H : HIRENASD

2. 2.3M 3M cel ells 53K 53K nod nodes

Aerodynamic amic E Equil ilib ibriu ium m at d different A AOA St Static St Structure, St Stead ady air airflow at w at de deformed sh shape ape Ma=0. =0.8, 8, R Re=23. e=23.5x106, q/ q/E=0. =0.48x10-6

Wing Tip Displacement Lift Coefficient

Wi Wind ndoff Vibrat atio ion M Modes : s : Ab Abaqu qus vs vs Experi riment

f=25. 5.55 55 Hz (26. 6.25 25) f=80. 0.25 25 Hz (78. 8.20 20) f=106. 06.20 20 Hz f=160. 60.35 35 Hz (165 65.25 25)

NASA ASA FUN3D

Aeroelastic Equilibrium Cp: AOA 2°

ST STAR AR-CCM CM+/Abaqu baqus

x/ x/c

Aer eroe

• elas

astic Equilib ilibriu ium Cp: AOA 2°, near wing tip

ST STAR AR-CCM CM+/Abaqu baqus NASA ASA FUN3D

Fluid id-Elast astic ic I Inst stab abil ilit ities i s in a Tube B Bundle Weaver & & Ab Abd-Rabbo

• bbo. A

A Flow V Visu sual aliz izat atio ion S Study o

• f a Squar

are Arr rray of y of Tubes i in Water Crossflo

• flow. J

Journal al o

• f Fluids

ids Engineeri

• ring. S

. September 1 r 1985. Vol. 1 . 107, p

• p. 354-363

363.

Fluid id-Elast astic ic I Inst stab abil ilit ities i s in a Tube B Bundle

Vortic icity Vu=0.25m/s Vu=0.31m/s

STA TAR-CCM CM+ D Developm pment D Directio ions

– Introduce and couple more physics within STAR-CCM+ – Allow for co-simulation with a multiple of CAE solvers

FEA Mod Models In Introduced

– 3D continuum, shells, and beams – 6 DOF Beam to/from Fluid Wall Surface Mapping

STA TAR-CC CCM+ C Co-si simu mulat atio ion A API

– Coupling to CAE Vendor Codes – Coupling to In-house Codes

Fut utur ure D e Devel elopment ents in in STAR-CCM CM+

Ma Many F y FSI c I cha hall llenges Demonst strat ated i d indust strial al “ “strength” e exam ampl ples o s of STAR-CCM CCM+ The The k key e y enablers rs of

• f the

he t techn hnology a are re

– VOF for free surface transient flow – Overset Technology for motion and deformation – Fluid interaction with

• multi-body rigid structures
• deforming structures

– Mapping between non-conformal meshes – Co-Simulation Application Program Interface – Parallel scalability on compute clusters

Conclusions

Than ank Y You For Y Your A Attention