Defining deformable mesh UDF to set omega

Chris

I'm trying to do an analysis on a spur gear oil pump. I want to define a constant omega value for the gears about an axis, the UDF I tried to use is:

#include "udf.h"

DEFINE_CG_MOTION(speed, dt, vel, omega, time, dtime) { omega[0]=25; }

I can load the UDF but it will not induce rotation.

Am I right that the [0] defines the axis of rotation?, can anyone explain what I have done wrong?,

Any help would be much appreciated.

Chris