[richard.chung.jones]

Dear Foamers,
Currently I am stuck with dynamic mesh. I need to do a simulation, which involves a metal solid flap in a water tank, rotating a certain angle to generate a vortex pair on the bottom wall.
Firstly I think of solidBodyMotion with tabulated6DoFMotion to prescribe the motion of the flap. However, after the first simulation I found out that the neighbouring mesh points stand still at their position, resulting in a poor mesh quality. I know that dynamicMotionSolverFvMesh enables mesh morphing but it does not have a parameter or a BC for inputting motion profile.
So far I am able to “move the flap” by defining the motion in 0/pointDisplacement file, using angularOscillatingDisplacement BC. However I want the flap to move accordingly to my prescribed, tabulated motion profile. Is there a way to achieve this?

Code 1. The dynamicMeshDict

FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dynamicFvMesh dynamicMotionSolverFvMesh;

motionSolverLibs ("libfvMotionSolvers.so");

solver displacementLaplacian;

displacementLaplacianCoeffs
{
    diffusivity  inverseDistance 5.0 (flapPatch);

    report            on;
    reportToFile      on;
}

Code 2. 0/pointDisplacement

FoamFile
{
    version     2.0;
    format      ascii;
    class       pointVectorField;
    location    "0";
    object      pointMotionU;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 0 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    front
    {
        type            empty;
    }

    back
    {
        type            empty;
    }

    top
    {
        type            uniformFixedValue;
        uniformValue    (0 0 0);
    }

    zeroGrad
    {
        type            uniformFixedValue;
        uniformValue    (0 0 0);
    }

    ground
    {
        type            uniformFixedValue;
        uniformValue    (0 0 0);
    }

    flapPatch
    {
        type            angularOscillatingDisplacement;
        axis            (1 0 0);
        angle0          0.0;
        amplitude       0.11407;
        omega           0.18021;
        origin          (0.0 19.4 22.3);

        value           uniform (0 0 0);
    }

    symmetry_Y
    {
        type            uniformFixedValue;
        uniformValue    (0 0 0);
    }

    defaultFaces
    {
        type            uniformFixedValue;
        uniformValue    (0 0 0);
    }
}

Fig. 1 The overall mesh
Screenshot from 2017-10-18 14-34-39.png

Fig. 2 The flap that I wish to move
Screenshot from 2017-10-18 14-35-23.png

Fig.3 The required motion profile. The flap is initially tilted to certain angle from the vertical plane.
JFL_flap_angle.png