6dof error in fluent's dynamic message

manoj

Hi ! I am using fluent's 6 dof code in a model to simulate the trajectory of a small block inside a wind tunnel.I used unstructred nodes for meshing the geometry. I calculated the steady state conditions and then i turned on the unsteady and dynamic mesh modes. when i try to solve the mesh motion i am getting a -ve volume error and i got this message in the console window.

Mesh Statistics: Min Volume =-1.17434e-10 Max Volume = 9.95522e-02 Warning: negative cell volume detected! Error: Preview-Dynamic-Mesh failed Error Object: ()

I tried different time step size but still didn't work. can somone help me to solve this. Thanks in advance.