Abstract

The operation of the centrifugal pump itself is the cause of cavitation due to the possibility of formation and collapse of bubbles. It is commonly agreed that a microjet causes cavitation erosion or a shock wave generated at the moment of bubble collapse near a solid surface, producing a pressure ranging up to 1000 MPa and causing severe pitting and removal of material, decrease of the pump performance and total head. A study of more research conducted on the same lines is needed for a better understanding of the challenges of cavitation. In the present paper, we are using three different blade leading edge angles (?1) 9�, 15�, and 21� with a rotational speed of 1200 rpm and different flow rates (designed and off-designed) are applied in order to reduce the cavitation and enhance the pump performance by using CFD. Cavitation models are imposed by using Rayley-Plesset Equations. For each leading-edge angle, the performance of the centrifugal pump through head drops and total efficiency curves, pressure variation in the blade passage from hub to shroud, and vapor distribution on the blades at different span locations are discussed. With the preliminary results, by increasing the blade leading edge angle on the cavitation, it is observed that both the head and total efficiency increase at different operating conditions. For the blade leading edge angle of 9�, developed cavitation occurred at the leading edge on the pressure side, and for 21�, it is observed on the suction side. For a 15� leading edge angle, there is no cavitation development, and the danger of pump damage and erosion is eliminated. These are further discussed with respect to other results in this paper.

Description