UDFof paraboloid velocity
 

I am using a paraboloid(3-D parabola) velocity profile in my model with an average velocity of 2 m/s and diameter of tube is 5.6 mm. The origin is at the centre of the velocity inlet of the tube. The +Y axis is along the flow with inlet face on the X-Z axis. If anyone can send me the UDF in C language, I would really appreciate it.