CFD Online Discussion Forums - Creating meshes for FSI simulation

Hello,

I am currently trying to simulate blood flow inside an artery. I am using fsiFoam to solve the FSI problem. But I am having problems with meshing the solid artery wall and the fluid domain. Initially I tried to mesh them separately in snappyHexMesh but while trying to run the solver, I get an error of "Master point addressing not correct" . I suspect this is because of the gaps between the meshes.

I then tried multi-region meshing in snappyHexMesh but for some reason, the cellzone for the solid has 0 or very less (when the make the background mesh finer) number of cells assigned to it and when I run splitMeshRegions, it gives the fluid cellzone as the background mesh minus the fluid domain and an empty solid cellzone.

Could anyone give me pointers on how are meshes for FSI usually built? Maybe in snappyHexMesh or some other software like ICEM CFD? Or if anyone could guess why the cellzones arenot being correctly built by snappyHexMesh, do I need to just refine the background mesh a lot?

I have also attached an image of my geometry.

my snappyHexMeshDict

Code:





geometry

{

    FLUID.stl

    {

        type triSurfaceMesh;

    }

    SOLID.stl

    {

        type triSurfaceMesh;

    }

};



castellatedMeshControls

{



    

    maxLocalCells 2000000;





    maxGlobalCells 4000000;



    minRefinementCells 0;



    nCellsBetweenLevels 3;



    features

    (

        {

            file "FLUID.eMesh";

            level 0;

        }

        {

            file "SOLID.eMesh";

            level 0;

        }



    );





    refinementSurfaces

    {

        FLUID.stl

        {

            level (1 1);



            faceZone fluid;

            cellZone fluid;

            cellZoneInside inside;

        }



        SOLID.stl

        {

            level (1 1);



            faceZone solid;

            cellZone solid;

            cellZoneInside inside;

        }

    }



    resolveFeatureAngle 150;





    refinementRegions

    {

    }





    locationInMesh (0 0 50);



    allowFreeStandingZoneFaces false;

}







snapControls

{



    nSmoothPatch 3;





    tolerance 2.0;



    nSolveIter 100;



    nRelaxIter 5;



    nFeatureSnapIter 4;



    implicitFeatureSnap false;



     explicitFeatureSnap true;



     multiRegionFeatureSnap true;

}