[quarkz]

Hi,

I need my body to deform using displacementLaplacian, so mesh will deform according to the body's boundary (no reordering).

At the same time, I also want the whole body to pitch up.

However, if I use displacementLaplacian for the body deformation and pitch up motion, the mesh quality will deteriorate rapidly due to the large pitching motion.

hence, I'm thinking of rotating the entire mesh for the pitch up motion, and using displacementLaplacian for the body deformation.

Is it possible to combine it this way?

Also, in the relativeMotion tutorial, there is the "solidBodyDisplacementLaplacian".

Can I use it to achieve what I want?

Thanks.

[quarkz]

After spending some trial and error, I finally managed to get it working.

The wing will be deformed (according to your own preference) using solidBodyDisplacementLaplacian

In this example, I use angularOscillatingDisplacement

For the full body pitching, the whole grid will pitch up. Hence, grid quality can be preserved much better than simply full mesh deformation.

pointDisplacement file

FoamFile
{
    version     2.0;
    format      ascii;
    class       pointVectorField;
    object      pointDisplacement;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 0 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{

    wing
    {
    type      angularOscillatingDisplacement;
        axis            (0 -1 0);
        origin (0.03 0 0.235);
        angle0           0;
        amplitude       0.7854;  //units of rad
        omega           1.5708;       //units of rad/s
        value           uniform (0 0 0);
    }

    ".*"
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }


}

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

dynamicFvMesh dynamicMultiMotionSolverFvMesh;   //dynamicMotionSolverFvMesh;

// Specification of rotation around centre

dynamicMultiMotionSolverFvMeshCoeffs
{    
    dualWing1
    {
        cellZone AirfoilZone;

        // Solve displacement on top of solid-body rotation
		
		solver solidBodyDisplacementLaplacian;

        solidBodyDisplacementLaplacianCoeffs
        {
            solidBodyMotionFunction  multiMotion;
            multiMotionCoeffs
            {
                
                rotation_2
                {
                    // Apply counter rotation to keep dualWing aligned
                    solidBodyMotionFunction rotatingMotion;
				   rotatingMotionCoeffs
				   {
					   origin          (0.00896 -0.04056 0);//(0.4825 0. 0.);
					   axis            ( 0 0 1);
					   omega           -0.1745;    //5.52 rad/s
				   }
															
                }
            }
            diffusivity quadratic inverseDistance ("wing.*");
        }
    }
}

topoSetDict

FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      topoSetDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

actions
(
    {
        name    c0;
        type    cellSet;
        action  new;
        source  regionToCell;
        insidePoints ((-0.5 1. 0.0));
    }

    
);

topoSetDict_movingZone

FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      topoSetDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

actions
(
    {
        name    AirfoilZone;
        type    cellZoneSet;
        action  new;
        source  setToCellZone;
        sourceInfo
        {
            set c0;
        }
    }
);

With these files, run
1. topoSet
2. topoSet -dict system/topoSetDict_movingZone
3. renumberMesh, pimpleFoam or moveDynamicMesh etc.

Hope it helps!