Negative cell volume detected
I am using FLUENT dynamic mesh to simulate the oscillation and rotation of an object in a 3D fluid domain.
The motion of the object is defined the motion of each grid using DEFINE_GRID_MOTION and the motion of the object looks correct.
However, when I try to preview the mesh motion, weird thing happens: The Preview Mesh Motioin works fine without Autosave enabled (the time step size is 1e-4 s). After I enable the Autosave option (same time step size), the preview always fails due to negative cell volume detected after several time steps.
I have tried smaller time step size of 1e-5 s, which still does not work when the Autosave is enabled.
I am not sure if my dynamic mesh setting is wrong as posted below.
Any help and suggestions are appreciated. Thank you!