Appendix: example of rotor dynamics calculation
Rotodynamic pumps - Special mechanical problems

Consider the pump impeller shown in figure 13 between two identical leakage sections, one in front of the impeller, the other behind it. This impeller of mass 2M has its center of gravity G located midway between the two trailing sections. It is supported by a shaft that is sufficiently long and thin for the restoring forces coming from the shaft to be negligible compared with those coming from the trailing sections.

From a mechanical point of view, figure 13 is equivalent to figure