Influence of Volute Casing Design Methods and Changes in Geometric Parameters on Pump Operation

This article presents results from research whose purpose is to determine the impact of two main factors on the operational efficiency of a double-entry centrifugal pump. The first factor is the design methods, and the second is changes in the geometric parameters for the volute casing. The results of the numerical simulation were experimentally validated on a test stand. Within this study, volute casings were designed according to the constant velocity method and method of conservation of angular momentum of the flow. The geometric parameters were selected according to the recommendation of A. Stepanoff and A. Lomakin. Next, the following geometric parameters were changed: inlet diameter, inlet width, cross-sectional area, shape of the volute casing’s cross-section (trapezoidal vs. round) and the opening angle of the volute casing’s walls. A comparison of the two methods showed that the biggest difference between them is the influence on the shape of the pump characteristic curve. Altering the geometric parameters in trapezoidal or round volute casing cross-sections had minimal impact on the pump head and efficiency.