Effect of the volute tongue profile on the performance of a low specific speed centrifugal pump

Abstract

In this study, we investigated the effects of volute tongue geometry variation on the head, efficiency, and radial force of a centrifugal pump. Numerical simulation modeling based on [Formula: see text] turbulence with automatic near wall treatments was used to simulate the turbulent flow. The effect of blade position with respect to the volute tongue on instantaneous pump characteristics was investigated. The parametric studies were done for cutwater gap, tongue shape, and volute tongue angle. Numerical results showed that the large cutwater gap caused lower radial force, especially at high flow rates. Investigations using various volute tongue shapes indicated that the short tongue volute decreased the radial force at design and low flow rates. Considering all aspects, the most satisfactory volute tongue angle was found to be 5° less than the outlet velocity angle of the impeller; yielding about 40% lower radial force than others at the design point.