[shuiit]

I'm trying to simulate an oscillating beam in a highly viscous fluid (I defined the solver on low Re). I created a UDF (simulating the beams first mode) and used it to create deformation of the walls. When I run the preview I get the right motion, but, when I run calculation I get wrong results. (im supposed to get symmetric vortices on both side of the beam but I get only one.

Is using deforming is the right choice?
The motion supposed to be similar to vibration, I'm not Shure that this is what I get.

I would really appreciate any help, I'm trying to find the problem for days.