negative cell volume in dynamic mesh

WU zhonghua

To Flunet users, i am using a dynamic(deformed) mesh to study flapper valve movement in combustion chamber caused by the difference between the combustion gas and atomisphere pressure. when the program runing, it alaways show the message " error: update-Dynamic-mesh failed. negative cell volume detected error object: #f"

when i do the grid check, it shows in the console: checking face handedness zone 27: 8121 right-handed, 2-left-handed zone 7: 133 right-handed, 2-left-handed

i think the negative cell volume may be caused by the left-handed face handedness appeared in runing. the question is how to prevent this? should i change some controll parameters or remesh the grid? thanks for any suggestions.

WU Zhonghua