Modeling time dependent function in Abaqus/CAE

Hello,

I am very new to Abaqus so I apologize since I am probably using the incorrect terminology for this and asking a fairly simple question.

I would like to model a laser beam striking a part the part is rotating w.r.t. the beam and I would like to model this. I have already set up Cylindrical coordinate and I just want the beam to sweep the surface following the equation:

Theta = Omega * Time

where:

Theta:= Angular Position

Omega:= Angular Velocity

Time:= Time

If anyone can offer a suggestion as to how to do this I would be very appreciative.

Regards,

John