Performance prediction of mixed-flow pumps

Abstract

This paper presents the mean streamline analysis using the empirical loss models for performance prediction of mixed-flow pumps with high specific speeds. A new internal loss model to describe the effect of flow separation on the characteristic head-capacity curve with a dip in the low flow range is developed and a modified recirculation loss model for calculation of parasitic loss due to flow recirculation at the impeller exit is suggested in this study. The prediction performance of the proposed method here is tested against four sets of measured total heads and efficiencies of mixed-flow pumps, and it is also compared with that based on two-dimensional cascade theory. Predicted results by the present set of loss models agree very well with experimental data for a variety of mixed-flow pumps over the normal operating conditions.