On the Improvement in the Suction Performance of High-Head Axial-Flow Pumps

Abstract

The optimum diameter of axial-flow pumps has been theoretically studied taking the suction performance into consideration. Two high-head axial-flow pumps, composed of two tandem impellers, were tested to study their characteristic performances and suction performances. The main results of the study are as follows. The optimum flow coefficient decreases with the cavitation coefficient of the blade section. The pump, which demonstrates better suction performance and efficiency, consists of a lightly loaded 1st stage impeller with high stagger angle and a heavily loaded 2nd stage impeller of somewhat larger flow coefficient.