涡旋液压泵内部流动与压力脉动的数值模拟

Numerical Simulation of Flow and Pressure Pulse in Scroll Hydraulic Pump

采用CFD技术对涡旋泵内部流场进行三维非定常模拟,得到了不同转角下工作腔内压力、速度、气相体积分数以及进出口流量等参数,并进一步分析了泵内的压力脉动。研究结果表明:由于泵进口位置的不对称以及高速旋转下动盘对油的扰动作用,导致2个工作腔内流动的不对称;在高压差的作用下,动静盘啮合间隙处存在高速射流现象,并在间隙下游产生大面积的空化;在吸液末期和排液初期工作腔内会产生较高的压力脉动,严重影响泵的稳定性;通过降低转速、增大轴向间隙、缩短型线长度等方法可有效改善压力脉动现象。

This paper uses CFD technology to perform three-dimensional unsteady simulation of internal flow field of scroll pump,and obtains the pressure,velocity,gas volume fraction and inlet and outlet flow parameters in the working chamber at different rotation angles,and further analyzes the pressure pulsation in the pump.The research results show that:due to the asymmetry of the pump inlet position and the turbulent effect of the moving disk on the oil under high-speed rotation,the flow of the two working chambers is asymmetrical;under the action of the high pressure difference,there is a high-speed jet phenomenon at the meshing gap between the moving and static disks.And a large area of cavitation is generated downstream of the gap.Higher pressure pulsation will be generated in the working cavity at the end of liquid suction and initial liquid discharge,which will seriously affect the stability of the pump.The pressure pulsation can be effectively improved by reducing the speed,increasing the axial gap,and shortening the length of the profile.