Effects of blade-tip squealer geometry on the working performance of a helico-axial multi-phase pump

Abstract

Tip-leakage flow occurs in the tip-clearance region of helico-axial multi-phase pumps, and this reduces their working performance. In this study, a structural modification, in the form of the inclusion of “squealers” on the impeller blade tips, was adopted to reduce the tip-leakage flow in a helico-axial multi-phase pump, thereby improving its working performance. Numerical simulations were conducted to examine the impact patterns of geometric parameters such as the depth, shape, and size of the squealer on the external characteristics and tip-leakage flow. The results of this study show that the presence of squealer tips has significant effect on the performance of a multi-phase pump. The depth of the squealer and the ratio of the squealer length to the blade-tip length were found to be the critical structural parameters of the squealer. There is an optimal value for the relative squealer depth, and this was found to be 9%. Larger ratios of squealer length to blade-tip length were also found to be more favorable for improving the performance of the multi-phase pump. The width and location of the squealer were found to have relatively low impacts on the performance of the multi-phase pump considered in this study. The presence of squealer reduced the tip-leakage flow rate and also alter the structure of the flow field in the impeller blade-tip region, changing the periodic distribution pattern of tip-leakage flow to some extent. The results of this study have important guiding significance for improving the performance of helico-axial multi-phase pumps.