Study on the blade squealer tip affecting tip leakage flow and performance of a multiphase pump

Tip clearance is the distance required between the blade tip and the pump body wall of an impeller in a helicon-axial multiphase pump, which tends to induce tip leakage flow. The tip leakage vortex formed by the interaction of tip leakage flow with the mainstream can seriously affect the performance of the multiphase pump. To minimize the adverse effects of tip leakage flow in the multiphase pump, a method to design a squealer tip on the impeller blade is proposed in this paper. The effect of the squealer tip on external characteristics, tip clearance flow characteristics, and energy dissipation of the multiphase pump is analyzed. Research results indicate that the blade squealer tip can effectively improve hydraulic efficiency of the multiphase pump. At the optimal efficiency point, the head and hydraulic efficiency of the multiphase pump with a squealer tip increased by 3.62% and 4.15%, respectively, compared with the original model. The influence of tip leakage flow in the axial rear half passage of the multiphase pump impeller is far greater than that in the axial forward half passage, especially on the back position in the middle of the impeller passage. The squealer tip can restrain the reverse of leakage flow from the pressure side to the suction side of the impeller blade, and the clearance leakage flow of the model with a squealer tip is smaller than that of the original model. The squealer tip on blade will reduce the energy dissipation caused by unsteady flow in the mainstream. The research results in this paper can provide theoretical support for effectively restraining the influence of the tip leakage vortex on the mainstream of the helicon-axial multiphase pump and contribute to engineering practice value of improving the performance of the multiphase pump.