The starting and stopping processes of a centrifugal pump are essentially transient processes, where the hydraulic performance changes with the rotational speed of the pump. In this paper, the CFD simulation is made by changing the impeller rotational speed over time for the type IS125 centrifugal pump to study the transient internal flow field and the external performance of the pump during starting and stopping processes. The entire simulation consists of four stages, including the startup, the normal running, the stopping and post-stopping of the pump. The variations of the flow field are obtained from the transient simulation. The flow-rate, the head and other external performance parameters against time are also obtained, which can be used in pump designs and actual operations.

varied-speed method  /  starting and stopping processes of centrifugal pump  /  transient flow field  /  numerical simulation