Oscillation flow on circular pipe by fluent
 

Hello every body
I m working on simulation of oscillating flow on circular tube with const. Re and three different Wo
The pressure gradient (at first Wo) = c . Cos(1.87777778t) & c vary from -4 to 4
I cant find any way to write UDF for this case
If any one have experience about that it will be great
Thank you