Inlet Reverse-Flow Model and Prediction of Theoretical Head and Water Power of Mixed-Flow Pumps

In order to predict performances of mixed-flow pumps over the whole discharge range, it is necessary to establish a calculation method of theoretical head and power loss caused by a reverse flow at the inlet and the outlet of an impeller. In this report, a reverse flow model at an impeller inlet is proposed together with the dependence of the slip factor upon discharge, and a prediction method of theoretical head and water power of mixed-flow pumps by a simple calculation is presented using this inlet reverse flow model. The comparison with the measurements revealed that the present method yields a good prediction for the inlet velocity distribution and for the theoretical head and water power in the whole discharge range