Mee eeting ing t the C e Chal allenges enges of of F - PowerPoint PPT Presentation

Mee eeting ing t the C e Chal allenges enges of of F Fluid-Str tructu ture I Interacti tion Alan Mueller, Chief Technology Officer

What at is F is FSI SI? Air Interac action wit ith a a Flexible S Structure

What at is F is FSI SI? Water/Air I Interac actio ion with a a Structure

What at is F is FSI SI? Vortex Induced V Vib ibrat ation an and Gal allo loping 4

What at is F is FSI SI? Aeroelas astic F Flutter 5

What at is F is FSI SI? Hyd Hydroplan aning 6

What at is F is FSI SI? Gulp ulping ng 7

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 answe wers 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 8

The C The Cha hallenges of of FSI Mappin Map ing d dat ata a techniques – Finding neighbors and interpolating Protocols a and format ats f for exchan anging data – Getting data from Code A to Code B Coupling methods – Algorithms for accuracy, stability Dynam amic ic fluid mesh evolu lutio ion – Topology changes in the fluid domain Valid alidat ation of F FSI r result lts 9

Th The Ch Challenges o of FSI MAPPI APPING NG 10

The 3 The 3 steps of of “Ma Mapping” Searching Sea g for opposing n nei eighbors Interpola latin ing source s stencil dat ata a on a a tar arget point – Source and targets may be face or vertex Often en requires i integr egration (quadratures es) – intensive extensive variables • pressure force • heat flux heat – FEA nodal loads: integration of intensive variables against the shape function. 11

Source N So Neig ighbor Se Sear arch I Impe perative Sear arch r requir ires l lit ittle user in intervention The sear arch exclu ludes potentia ial l neig ighbors bas ased o on p proximit ity an and orientatio 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 12

Co Co-Simulation on V Vehi hicle The Thermal Ma Management

Mappi apping D Disp isplac acement in in Low w Y+ Pr Prism M Mesh shes C 0 continuous mapping very important for low y+ meshes Otherwise very easy for morpher to invert high aspect ratio cells in prism layer 14

The The C Cha hallenges of of FSI DATA E A EXCH CHANG ANGE 15

Metho hods f for E Excha hanging D Data File e Based ed Transfer er: Imp mport/Map/Export – Data exchange via files on a hard-disk – CAE codes need not be resident in memory – Often called “Loose Coupling” – User responsible for exchange synch Socket Based ed Transfer er: Co-Sim imulat atio ion API – CAE code and STAR-CCM+ in memory – Data exchanged via sockets – API controls exchange synchronization 16

Abaqu Ab qus/STAR-CCM CM+ C Co-Sim Simulat atio ion Coup upling ng via Abaqus us Co-Sim imulat atio ion API of SIMULIA – Manages Coupling Synchronization/Exchange/Mapping – Abaqus v6.12/STAR-CCM+ v7.04 (implicit coupling) STA TAR-CCM CCM+ Abaq aqus (explic icit it o or stan andar ard) – Initial geometry – Pressure(relative or absolute pressure) – Shear traction – Surface heat flux Ab Abaqus s STA TAR-CCM CCM+ – Displacement, velocity – Temperature 17

Ab Abaqu qus/STAR-CCM CM+ C Co-Sim Simulat atio ion I Interfac ace Hit the Step or Run button to commence the co-simulation 18

The The C Cha hallenges of of FSI Co Coup uplin ing T g Tech echniq nique 19

Degre rees o of Coupli ling Two-way Tw y couplin ling f for ae aeroelas astic or hydroela lastic ic equilib ibriu ium One way On y stat atic ic coupling for thermal stresses – structural temperature computed by CFD CHT One way On y dyn ynamic c couplin ing – Loads only go from fluid to structure – Loads only go from structure to fluid Two way dynam amic ic c coupling – explicit (exchange once per time step) – or implicit (multiple exchange per time step) 20

The C The Cha hallenges of of FSI Dyn ynami mic Mesh esh Ev Evolu luti tion 21

Dyn ynamic Me Mesh E h Evol olution Completely def define a go good quality fluid d mes mesh – Using as little user intervention as possible Op Options w within STAR-CCM CCM+ – Rigid body motion, sliding interfaces – Morphing – User Defined Motion Over erset Mes esh 22

Overs rset Me Mesh Mo h Motion a and F Flu luid F Flo low : : Stop V Valv lve

Th The Ch Challenges o of FSI Val alida idatio ions 24

AeroElast astic ic Predic dictio ion Work rksho hop: H : HIRENASD 53K nodes 2.3M cells

Aerodynamic amic E Equil ilib ibriu ium m at d different A AOA Stat atic ic Structure, Steady air airflow at at deformed shap ape Ma=0.8, Re=23.5x106, q/E=0.48x10-6 Lift Coefficient Wing Tip Displacement

AOA 2 ° Cp Cp: AO STAR-CCM+/Abaqus FUN3D

AOA 2 ° , S Cp Cp: AOA Stat atio ion 7 x/c STAR-CCM+/Abaqus NASA FUN3D

Wi Wind nd-off Vibrat atio ion M Modes : s : Abaqus s vs vs Experi riment f=25.55 Hz (26.25) f=106.20 Hz f=80.25 Hz (78.20) f=160.35 Hz (165.25)

AeroElast astic ic Predic dictio ion Work rksho hop: : Forced V d Vibrat atio ion o of 2 nd nd Flap Be ap Bending M Mode de Wing Tip Response of Cp Magnitude Phase

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 Visual aliz izat atio ion S Study dy o of a Squar are A Array o of Tubes i in Water r Cr Crossflow” HydroDynamic Damping: Vibration RMS vs Inlet Velocity: Tube Bundle Vorticity Simulation vs Measured Simulation vs Measured 31

Co Co-Simu Simulat ation D DOT T Tank I Impact Experimental Test Impact 32

DOT T Tan ank I Impac pact Sim Simulations Von Mises Stress (Abaqus Explicit) 33 STAR-CCM+ Pressure

DOT Tank Impact Comparisons 34

The C The Cha hallenges of of FSI Mappin Map ing D Dat ata a Techniques Procedu edures es f for Exchangi ging Data Coupling Methods Dyn ynamic Flu luid id Me Mesh Evolution Valid alidat ations 35

Than ank Y You For Y Your A Attention & & Enjo joy 36