Abstract: The existence of tip clearance causes tip leakage vortices in a mixed pump, imposing a greater impact on its pressurization performance. This paper studies quantitatively the effects of different tip clearances on the pressurization performance of a multiphase pump; based on this, the effects of flow rate and inlet air volume fraction are examined. We found that the influence of tip clearance is suppressed largely in the impeller section, and an increase in the tip clearance has a certain inhibitory effect on pump performance. At a small tip clearance, the flow has a significant effect on the performance of the impeller, while at a large tip clearance, it has a relatively smaller effect on the pressure load distribution of the blade surface. When the tip clearance is 0.5 mm or 1.5 mm, the inlet air volume fraction becomes larger, and the pressure load decreases significantly on the suction side while increases slightly on the pressure side. When the tip clearance is 1.0 mm, the inlet air volume fraction affected less on the blade surface. The results provide reference for the improvement in the pressure-boosting performance of the mixed pump.

Key words: tip clearance, multiphase pump, pressurization performance, inlet air volume fraction, pressure load