[aegean333]

I want to set a box in a coarse mesh and only refine this part. This refinement box should be moving along z-axis with constant velocity. Which of the dynamicFvMesh methods can achieve? (e.g. dynamicRefineFvMesh, dynamicMotionSolverFvMesh, dynamicInkJetFvMesh, solidBodyMotionFvMesh… )

[fredo490]

if your box is perfectly rectangular and never change shape, you can use the example of the "piston" motion. You can use the layerAdditionRemoval technique.

page 25 of this document: http://www.modlab.lv/docs/2011/OpenF...Rusche_pdf.pdf

[francescomarra]

Dear Foamers,

I need your help to setup correctly a case with two moving pistons. I was able to define their motion by using the setup described here below (openFoam version 2.3).
The file constant/dynamicMeshDict defines the following:

dynamicFvMesh   dynamicMotionSolverFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

solver          velocityComponentLaplacian;

velocityComponentLaplacianCoeffs
{
    component       z;
    diffusivity     uniform;
}

Then, in the file 0/pointMotionUz are defined two separate boundaries with different motion:

boundaryField
{

    botCyl1
    {
        type codedFixedValue;
          value uniform 0;
          redirectType rampedFixedValue;
          code
          #{
              (*this)==(0.5*sin(2.0*3.14*this->db().time().value()/0.01 ));
          #};
    }

...

    botCyl2
    {
        type codedFixedValue;
          value uniform 0;
          redirectType rampedFixedValue;
          code
          #{
              (*this)==(0.5*cos(2.0*3.14*this->db().time().value()/0.01 ));
          #};
    }

Unfortunatly this does not work: only the first rampedFixedValue is assigned to both boundaries.

How I can assign two independet motions ?

Thank you in advance for any advice,

Franco