Combined Orbital/Rotation motion is another combination motion mode--the object rotates about its axis of rotation, and also orbits about an axis parallel to its axis of rotation. Rotational motion is described in the Angular Motion section of this chapter.
A typical application for Combined Orbital/Rotational motion is a pump shaft with an eccentric orbit (or whirl) component. The shaft rotates about its centerline, but also has an eccentric rotation about an additional axis.
Both motions can be either user-prescribed or flow-driven. If the orbit is flow-driven, then the forces acting on the moving object are summed and appropriate accelerations are computed. Velocities and displacements are limited to the circular orbital path using the following relationships.
The two elements of Orbital motion, the rotation and the orbit, are defined independently as User-Prescribed or Flow-Driven. The Flow-Driven check boxes on the Motion task dialog govern how each element is defined on the Material Editor. The possible combinations of user-prescribed and flow-driven are listed: