Dynamic mesh, negative volume, help!
 

Hi, I'm using FLUENT v 13.

it's a 3D case with a model of a cylinder. the motion of the cylinder is in xy plane. I use smoothing and remeshing strategy.

it works well in 2d, but when I change to 3D, after some iterations, the skewness of the first layer mesh outside the rigid moving body get very high, and negative volume appear.

Can anybody help me?
Thanks a lot