[omidvar]

I wrote a simple UDF code for describing pitching motion of a
projectile as below:
#include"udf.h"
DEFINE_CG_MOTION(pitching,dt,vel,omega,time,dtime)
{
omega[2]=20.0*cos(10.0*time*3.1416/180.0);
}

But when I wanted to create dynamic mesh zone, Fluent reports:
"Warning: incorrect cg motion UDF pitching on zone 10 (assuming no motion)"
I confused, I searched udf manual and cfd online forums but I couldn't
find the reason of problem.
If someone know the solution please help me.