Trip with Inertia

The Trip with Inertia transient is the second of two inertial transients that can be defined for the Centrifugal (Rotodynamic) Pump. Modeling an inertial pump trip allows the representation of a situation where a pump is operating normally, but all motor or driver torque is instantaneously lost. This trip is uncontrolled - meaning that the torque characteristics of the pump alone will drive the speed change behavior.

Inertial Characteristics

The total rotating inertia of the pump/motor system must be available. This must include all rotating components - the motor rotor, shaft, impeller, entrained liquid, and any other connected components. This value can be estimated or directly specified.

Transient Data

No further data is required from the user to define a trip.

To solve the torque balance equations, the torque on the shaft at any given speed must be known. The torque exerted by the pump on the shaft (that is, from the fluid) can be determined with the Standard Pump Curve, which is already defined. The torque of the motor or driver is assumed to instantly fall to zero.