udf for dynamic mesh
 

Dear all,
I am simulation one problem of dynamic mesh in which a cylinder is moving inside a rectangular channel. I am doing the 2D analysis of the problem. In my dynamic mesh motion the cylinder is moving along the x direction only, so I set the value for v[0] only. Now i have some doubts regrading the problem:
1. Whether I have define the whole fluid domain as deforming or not? I am using smoothing and re meshing as the mesh methods.
2. How to define the motion of the cylinder (which I have defined as rigid body and the motion is defined in the udf), when it is moving along a plane say "y=a*x^2+b*x+c, where v[1] is dependent on both x coordinate as well as v[0], how to incorporate this in udf.

any help is highly appreciated..

pl. help me...