Hey,

I have a very simple model involving a rectangular duct with air blowing through it. A bottom part of the duct is supposed to move down at a fixed velocity. I use a UDF and a rigid body deforming defitinition for the moving wall. The connected walls are all deforming. My UDF definition works in 2d but not in 3d. If I try to model the mesh motion I get a FATAL ACCESS VIOLATION ERROR after the first time step. My UDF looks like this

DEFINE_CG_MOTION(.....) { vel[1] = -0.05; }

If anyone has any ideas why this is not working, I would really aprrecfiate the help.

Hi, Have u tried using DEFINE_GEOM, UDF to restore the geometry of the wall? I think this will work, if u use along with DEFINE_CG_MOTION. Again it wont be easy u have to play with the boundary node relaxation and spring factor.

Regards, devan