[Svensson]

Hello everybody. I am trying to simulate an experiment, which I've conducted earlier. And I have faced with some difficulties. An Experimental apparatus is a tank filled by liquid (there is no free surface) . An internal volume of the tank is fluid-tightly devided into two equal parts by internal thin baffle. One of them is filled by liquid with dissolved NaCl (heavy liquid) and another one is filled by pure water (light liquid). In the time t=0 baffle begins moving and is completely removed from the tank by the time t=2.8 s. Below is experimental scheme

.

I don't know how to simulate thin removing baffle. And I would be glad to get advice.

Best Regards, Alexander.

[ThomasV]

Hi!

Did you have a look at the incompressible -> pimpleDyMFoam -> movingCone case?

[Svensson]

Originally Posted by ThomasV

Hi!

Did you have a look at the incompressible -> pimpleDyMFoam -> movingCone case?

Yes. I've seen it. I tried to use this technics, but I couldnt solve problems caused of a mesh movement. While baffle was moving, cells located near the top wall became more and more warped with high aspect ratio. I tried to set an dynamicMeshDict to add cell layers on the top wall and to remove ones on the lower wall, but I didn't have success in it. I'll add some pics of the mesh in the evening.

[Svensson]

here you are (it's a simplified model):




My dynamicMeshDict:

dynamicFvMesh   dynamicMotionSolverFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

solver          velocityComponentLaplacian;

velocityComponentLaplacianCoeffs
{
    component       z;
    diffusivity     directional ( 200 0 100);
}

and pointMotionUz:

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    movingWall
    {
        type            uniformFixedValue;
        uniformValue    constant 100;
    }
    slipWalls 
    {
        type            slip;
    }
    fixedWalls
    {
        type            uniformFixedValue;
        uniformValue    constant 0;
    }

    frontAndBack
    {
        type            empty;
    }
}