Effect of semi-open impeller side clearance on the centrifugal pump performance using CFD

Abstract Centrifugal pumps (CP) are probably among the most often used machinery in industrial facilities as well as in common practice. Compared to other types of rotating pumps, CP yield higher efficiency. In aerospace application, reducing the weight of the CP impeller has the advantage of reducing mechanical stresses and enable using the CP at the high number of revolutions. In order to minimize the impeller weight the requirements to study and develop the CP with semi-open impeller appear. The present paper is devoted to revealing more details about the impact of CP side clearance on its performance. This is done by numerically investigating the influence of the variation of the CP side clearance width (0:0.2 impeller width) on the CP performance parameters at different flow rates (0:5 L/s). These CP performance parameters include the pump head, efficiency, slip factor, blade loads and the internal flow structure. The numerical simulation has been compared with own experimental results and a published empirical formula to verify the numerical solution. The CFD results show an acceptable agreement with the results of the experimental work and the empirical formulas. It has been shown that the impeller side clearance has a great regression effect on the centrifugal pump performance.