(98a) Improved Centrifugal Pump Performance with Counter Helical Inducer Housing Grooves

Net positive suction head required (NPSHR) is closely related to inducer performance and is an important requirement for overall pump performance. The ability of an inducer to propagate fluid towards the impeller inlet is greatly diminished as the fluid begins to rotate with the impeller blades. By machining helical grooves in the inducer housing that are in a counter rotation to the inducer blades, the fluid that has rotational energy is channeled up the grooves and towards the impeller. The helical groove concept was tested on an axial centrifugal pump and yielded positive results. NPSHR level was improved with the modified grooved inducer inlet housing without significant change in the head, power, or efficiency when compared to the same pump without the modification.