[MarcelK]

Hi all,
I use foam-extend 3.1 and want to compute the HronTurekFsi tutorial case located under tutorials/solidMechanics/icoFsiElasticNonLinULSolidFoam/HronTurekFsi using the icoFsiElasticNonLinULSolidFoam solver.
In the paper Turek, S.; Hron, J.: "Proposal for numerical benchmarking of fluid-structure interaction between an elastic object and laminar incompressible flow", Fluid-structure interaction, 371-385, the authors refer to three different benchmarks FSI 1 to 3, where the density and shear modulus of the structure and the mean inflow velocity are varied.
From the input files of the tutorial case, I understand that the density of the structure is 10 kg/m³, the shear modulus is 0.5 * 10^6 kg/ms² and the mean inflow velocity is 2/3 * Umax = 1 m/s. Hence, the input data indicates that the FSI 2 benchmark is computed.
When launching the case, everything runs just fine without applying any changes to the tutorial setup but when inspecting the results, I really wonder about the results. From the benchmark, I inspect a large deflection of the flag attached to the cylinder but the deflection in x-direction varies in the range -1.07e-6 .. 1.02e-6 and the maximum tip deflection in y-direction is 2.89e-5 (stationary from a few seconds simulation time on). Can anybody confirm this? Or am I missing something obvious here? Any help is greatly appreciated!

[Svensen]

The same question...

[Maimouna]

Dear Both,

did you get the answer of your question? I have the same question, if yes, provide me please.

Best, Maimouna

[Svensen]

I think that no one find the answer for this question... the problem is that foam-extend doesn't have a good user support..

[richpaj]

I think you have to run it for long enough for asymmetric perturbations to build up, or introduce these artificially to speed things up cf.

https://www.youtube.com/watch?v=ZaGiFeyIDdg

looks quite dramatic.

Rgds.

[rasool_soofi]

Hello Dear


I am using icoFsiNonLinULSolidFoam solver for simulating the one way valve.

Because of extreme change of valve's throat , DynamicMotionFvMesh class is not a good scheme for my case. I want to know that , can this solver support other dynamic scheme defining in foam-extend-3.1 ( for example dynamicTopoFvMesh or dynamicRefineFvMesh , etc) for re-meshing or refining the regions that have bad meshes during solution .


Could you help me to solve this problem


Best Regards

[rasool_soofi]

Hello Dears
i am using this solver for my case.
in the tutorial case of this solver the properties of fluid and solid set to

fluid density = 1 kg/m3 kinemaic viscosity = 10e-3
solid density = 10 kg/m3

what is the meaning of this properties.?
when i set my real properties for blood and vessel

blood density = 1000 kg/m3
vessel density = 1200 kg/m3

my solution crashed by " complex eigenvalue detected for tensor ...." error.

best regards

[rasool_soofi]

hi
did you get the answer of your question? I have the same question, if yes, provide me please.

[richpaj]

Hi there,
I've found that in order to get stable FSI it's advantageous to first obtain an accurate CFD solution. Initially then, I'd run the CFD solver until the residuals in pressure, in particular, were "reasonable" and then would switch on full FSI.

From personal experience I try to adhere to the standard hex-based motion solvers where possible owing to their superior performance during subsequent
CFD solution. The tet-based solvers by contrast usually require a lot of non-orthogonal correction in addition to other elements of tuning.

In regions of rapid mesh movement (e.g. close to the exit of a nozzle
geometry for example) it should be possible to define a suitable motion viscosity (1/distance^2 from a suitable patch, for example).


I hope that helps.

Rgds,

RGK

[popa]

anyone knows the reason?i run the simulation with a thirdpart tool,finally get the result,but i still konw why?