Description: rotor critical speed calculated considering the additional support and damping produced by the action of the pumped liquid within internal running clearances at the operating conditions and allowing for stiffness and damping within the bearings; Name: wet crit. Speed
Description: Rotor resonant frequency calculated considering the additional support and damping produced by the action of the pumped fluid within rotor  ; Name: Wet 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