unsteady parabolic velocity profile
 

I wish to apply an unsteady parabolic velocity profile to the inlet of a pipe.
I need the velocity to change from 7.5mm/s to -7.5mm/s in a sinusoidal pattern over a period of 3.2 seconds.
In other words, i am looking to apply a BC which varies both with respect to time and with respect to space at the inlet. I am using Star CCM+.

Has anyone any idea how to create a field function to do this?

Any help would be hugely appreciated!