Rotation around a local coordinate system

I want to set up the situation as shown below, where the left end face rotates around the CP-Aft and the right end face does the same. It's a matter of rotating around a local co-ordinate system, as my origin is in the middle of the model shown in the picture. And I want to set a constant rotation speed, what keyword should I use? 

Before I started this topic, I have tried the following keywords: 1. BOUNDARY_PRESCRIBED_MOTION, but it can only be used in the global coordinate system; 2. LOAD, which can only set forces and moments, not displacements or velocities; 3. INITIAL_VELOCITY, which can only set the initial velocity, not the constant velocity.