I have been working on a water valve scenario that have the valve changing position 5 degrees every 5 seconds. I first ran an analysis with the vavle in the full open position to make sure everything worked properly and then added the rotation. When the compare the results of the two analysis I get different results for the full open position. When the scenario is set up to run full open the results show a .5gpm leak but when motion is added no leak is present. I am wondering what would cause this to happen. Both scenarios have the same setup as i am running no motion and then adding motion once the analysis has completed.
Are the meshes for both the same? Typically we turn the mesh enhancement off for motion, which may mean we are not capturing the leakage path.
Mesh it with the moving part outside of the model (move it in CAD) and move it back in for the run, using the inital position in the motion setup. Then you can manually turn the mesh enhancement back on and we will create a boundary layer before moving the solid part back in.
Much like the guide here
Here is the help page: http://help.autodesk.com/view/SCDSE/2015/ENU/?guid=GUID-C8FB4A11-2A9D-4DB8-80E5-1D0F050ED4B8
You can use the void fill if you like, provided you still have good inlet and outlet extensions.