不同工况下涡旋泵空化与性能的数值模拟

针对涡旋泵建立了含有实际间隙的三维流体域模型,采用CFD技术对其进行了三维非定常模拟,研究了不同转角下的内部流场,分析了不同工况下的泵内空化现象及其性能。结果表明:由于涡旋泵结构特点和运动方式,导致泵的2个工作腔内的流动具有不对称性;在吸液末期和排液初期,工作腔内产生较高的压力脉动,严重影响泵的稳定性;在高压差的作用下,动静盘啮合间隙处存在高速射流现象,受其影响在间隙下游产生大面积空化;在低吸油压力下,随着转速的增加,动盘对油液扰动增强、空化加剧,从而导致泵的容积效率下降;提高吸油压力,可以有效改善空化程度、提高泵的容积效率;保持涡旋泵排量不变,则泵的回转半径越大,其空化越严重。

Numerical Simulation of Cavitation and Performance of Scroll Pump Under Different Working Conditions

In this paper,a three-dimensional fluid domain model with actual clearance is established for the scroll pump,and the three-dimensional unsteady simulation is carried out by using CFD.The internal flow field under different rotation angles is studied,and the cavitation phenomenon and performance of the pump under different working conditions are analyzed.The simulation results show that the flow asymmetry in the two working chambers is caused by the inherent structural characteristics and the motion of the scroll pump.At the end of the suction and the beginning of discharge,higher-pressure pulsates in the working chambers,which seriously affects the stability of the scroll pump.Because of the high-pressure difference,there is a high-speed jet phenomenon in the gap,which results in extensive cavitation at the gap downstream.Under low suction pressure conditions,the disturbance of the moving plate to the oil increases with the increase of the rotation speed,hence,the cavitation intensifies,and the volumetric efficiency of the scroll pump decreases.Increasing the suction pressure can effectively improve the cavitation degree and the volumetric efficiency of the pump.When the flow rate of the scroll pump is constant,the larger rotation radius leads to higher cavitation and more severe leakage.