Study on the Unsteady Cavitation Flow Characteristics Inside the Mixed Transport Twin Screw Pump

抄録

With the development of screw pumps towards high speed, high pressure, and large flow rate, cavitation in screw pumps has become a phenomenon that cannot be ignored. Based on ANSYS CFX, use SST turbulence model and combine with Rayleigh-Plesset equation to effectively simulate the internal flow of mixed transport twin screw pump, analyze the changes in cavitation morphology and the evolution of cavitation within the entire cycle of the pump, and explore the degree of cavitation on the surface of the screw rotor and the changes in pressure and velocity at the monitoring point with rotation period under different inlet pressures and speeds, and then analyze the changes in cavitation of the twin screw pump under different temperature. The calculation results indicate that cavitation first occurs at the inlet and then gradually penetrates into the interior of the chamber, mainly concentrated in the inlet section and the first chamber. The inlet pressure has a significant impact on cavitation phenomenon. As the inlet pressure decreases, the cavitation intensity continues to strengthen, and the cavitation area also continues to expand. Rotating speed can also affect cavitation, but the effect of speed changes on cavitation is not as significant as that of inlet pressure changes. In addition, increasing the water temperature will also increase the cavitation area. This study reveals the characteristics of cavitation flow in mixed transport twin screw pump, which is of great significance in avoiding cavitation and improving pump performance.