摘要：Screw axial-flow pumps, with three different tip clearance values (RTC = 1, 2, and 3 mm), were respectively investigated to analyze the influence of key parameters on external characteristics and cavitation performance. The simulation results were in good agreement with the experimental values. The results showed that the external characteristics and cavitation performance of the screw axial-flow pump decreased as tip clearance increased. The RTC was not sensitive to the efficiency of large flow condition, and the decrease in head and efficiency of the pump in large flow conditions was smaller than that for small flow conditions. With the increase in RTC, the vorticity distribution in the impeller gradually spreads from the hub to the tip of the blade inlet. In the incipient cavitation stage, the cavitation was mainly located at the inlet of the blade suction-side near the hub. When the cavitation number reduces to the fracture cavitation state, the cavitation area further increased, almost filled the entire blade suction-side, and the pump performance rapidly went down. The simulation results of the pump were slightly higher than the prototype test values. It can be seen that the computational fluid dynamics numerical simulation can be used to optimize the design of screw axial-flow pump.
关键词：Screw axial-flow pump; tip clearance; cavitation; numerical simulation; experimental research
