Oscillating Cylinder
 

I am doing my final year project on cfd but my cylinder does not oscillates completely ie it oscillates only in the upper part and does not come down. Can Anyone find a way ouit to this situation??

Please explain your problem in more detail. With this little piece of information hardly anyone can give you advice.

I am getting a error saying "a bodyNum is assigned to a non-Fress fluid cell"

Unfortunately, this additional little piece of information is not sufficient to solve your problem.
In this forum most users help on voluntary basis. Being very unspecific often results in getting no answer at all.
I would suggest you to explain your problem in greater detail and answer questions like the following: What do you want to do? How do you want to do it? Which Software (for Meshing and Solving) do you use? Which settings, models and boundary conditions? If your software is well known, consider posting in the right subforums. Add some pictures or/and your work files. ... etc.

Right now, i only can suggest you to check your boundary conditions and your mesh... Probably not helpful at all.

With regards,
Sebastian