Description: Runner resonant frequency calculated taking into account the additional support and damping caused by the effect of the fluid in the impeller; Name: crit speed (wet)
Description: Rotor resonant frequency calculated assuming that the rotor is supported only at its bearings and that the bearings are of infinite stiffness ; Name: Dry critical speed
Description: variable quantity, which is not influenced by the control but is introduced into the control system from outside with the aim of making the final controlled variable follow it in a given relationship; Name: command variable