a modular and efficient simulation environment for fluid-structure interactions

ECT2008, Athens, 9/4/2008, Miriam Mehl, Bernhard Gatzhammer

A Modular and Efficient Simulation Environment

for Fluid-Structure Interactions

Miriam Mehl

Bernhard Gatzhammer

Department of Computer Science, TU München


Outline

no fluid solver details FSIce

motivation application programming interface modules data transfer coupling strategies numerical results


Plug-and-Play for FSI

Fluid Solver

Structure Solver

MpCCI

Coupling StrategyData Mapping


Structure Solver


Fluid Solver

MpCCI



Fluid Solver

Structure Solver

FSIce

Coupling StrategyCentral Surface Mesh


FSIce – Application Programming Interface

Fluid Solver

FSI_Init ()

FSI_Data_exchange ()

FSI_Finalize ()

FSI_Is_running ()

FSI_Is_new_interface_values ()

FSI_Is_implicit_converged ()


FSIce – Application Programming Interface

Fluid Solver

while (more time steps)Set time step lengthCompute values of next time stepStore values of next time step

end while


FSIce – Application Programing Interface

Fluid Solver

while (more time steps)Read coupling data from com.meshSet time step lengthCompute values of next time stepWrite coupling data to com.meshStore values of next time step

end while



Fluid Solver

FSI_Init ()while (more time steps)

Read coupling data from com.meshSet time step lengthCompute values of next time stepWrite coupling data to com.meshFSI_Data_exchange ()Store values of next time step

end whileFSI_Finalize ()



Fluid Solver

FSI_Init ()while (FSI_Is_running())

if (FSI_Is_new_interface_values())Read coupling data from com.mesh

Set time step lengthCompute values of next time stepWrite coupling data to com. meshFSI_Data_exchange ()if (FSI_Is_implicit_converged())

Store values of next time stepend whileFSI_Finalize ()


FSIce – Modules


FSIce – Data Transfer

How to map data from solver mesh to coupling mesh ?

Octree for efficient neighbour search

Some projection / interpolation included

Custom interpolations possible

Provided to user in package FSItools


FSIce – Coupling Strategies

Explicit (weak)

Implicit (strong)

Subcycling

Pre-computations

Many others possible: just extend supervisor


Numerical Results – Implicit vs. Explicit


Numerical Results


Numerical Results – Data Mapping

17.4 sec128,000512

14.3 sec32,000512

10.1 sec8,000512

2.6 sec8,000256

runtime# triang.Cart.res.

neighbourhood search measured on a Pentium M 1.6 GHz processor with 2048 kB cache


Conclusion

enhancements of FSI*ce

modular structure extendability, flexibility

integration of various components

first examples computed

future: more solvers, more coupling strategies


Thank you for your attention!



Future goal: Multigrid

Multilevel coupling mesh

Multigrid scheme controlled from coupling supervisor

Allows V, W, ... schemes without modifying solversFluid

Solver

a modular and efficient simulation environment for fluid-structure interactions

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