Design of Centrifugal Pump Impeller and its Effects on Cavitation

A centrifugal pump's function is to transport fluid from one system to another system, within minimum time. Impeller is a key component in centrifugal pump, it intakes fluid through hub of impeller axially and distributes the fluid, radially. The configuration of the impeller blades directly effects the performance. The current paper investigates the characteristics of the pump by altering the blade profile and exit blade angles. A destructive phenomenon of cavitation is greatly influenced by blade profile. Generally, the blades of impeller will have a steep fall from hub to tip or remain in same height from hub to tip. The present project investigates the performance by employing a volute rim connecting all highest points of the blade tips. The blades also rise from tub to tip allowing the fluid to have enough space to accumulate large volumes of fluid with minimal impact on the blades to hub. Any alteration in the geometry, blade profile has a significant influence on the performance of the pump. Npsh denotes the net pressure suction head that is the amount of energy at the pump suction available to exert pressure on the fluid, if the pressure required at the pump inlet to make the liquids flow through suction side without cavitation. This can greatly reduce the cavitation effects, helping the pump to sustain to the calculated service life. Simulation is carried out using ANSYS R 15 software in FLUENT module, with ICEM meshing and SST k-Ω turbulence model.