Kinematics

This section defines the displacement, velocity, and acceleration of a point located on a rotor in a suitable frame of reference. In general, two different frames can be distinguished, namely the space-fixed frame and the corotating frame. The rotor deformation can be observed in either of these frames. Depending on the frame of references used in a particular study, terms in the equations of motion will change. In the Rotordynamics Module, the rotor is not physically rotated. Rather, the effect of the rotation is accounted for with frame acceleration forces in the momentum balance equation. The different kinematic quantities are described in the following sections for the two possible reference frames.