Investigation of Blade Exit Angle Effects on the Performance of a Centrifugal Pump

Abstract

AbstractTo achieve the goal of developing energy-efficient mechanical systems, centrifugal pump designers often encounter problems of selecting and optimizing pump impeller geometry. This paper presents a theoretical approach to investigate the blade exit angle effects on the performance of a low specific speed centrifugal pump with standard closed impeller. The governing equations of the flow through pump impeller have been numerically solved by the one-directional method of characteristics of specified time intervals. The mathematical model is validated with the pump experimental performance curves. The numerical results have clearly shown the influence of impeller blade exit angle on the head, input power and efficiency of the considered pump. Indeed it has been found that both head and shaft power increased with the increase of the blade exit angle. Best efficiency is obtained for impellers with 15° and 30° exit angle.KeywordsCentrifugal pumpBlade exit angleMethod of characteristicsSlip factorShock losses