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Multiple AMI, decreasing time step.

Hello,
I am working on a simulation with two AMIs representing two rotors. When I use pimpleFoam, the time step size starts to decrease rapidly (from the initial deltaT=e-3 to e-23). I have tried initialising the solution with potentialFoam, the issue persists. I have also checked if the cells are connected as suggested in this post (Multiple AMI rotations not working).

Here is the dynamicMeshDict file.

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

dynamicFvMesh dynamicMotionSolverFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

motionSolver solidBody;

cellZone rotating1-cells;

solidBodyMotionFunction rotatingMotion;

origin (0 0 0);
axis (0 0 1);
omega 125; // rad/s

cellZone rotating2-cells;

solidBodyMotionFunction rotatingMotion;

origin (0.65 0 0);
axis (0 0 1);
omega -125; // rad/s
// ************************************************** *********************** //

Here is the controlDict

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

application pimpleFoam;

startFrom startTime;

startTime 0;

stopAt endTime;
//stopAt nextWrite;
//stopAt noWriteNow

endTime 0.5;

deltaT 1e-3;

writeControl adjustableRunTime;

writeInterval 0.002;

purgeWrite 0;

writeFormat ascii;

writePrecision 18;

writeCompression off;

timeFormat general;

timePrecision 6;

runTimeModifiable true;

adjustTimeStep yes;

maxCo 20;

functions
{
#include "forces"
}
// ************************************************** *********************** //

Any leads on why the timestep decreases to such low values would be appreciated.

Thank you.


OpenFOAM 15-07-19, 3:12 p.m. sg_03

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