颗粒对离心泵内部压力脉动特性的影响

Effects of particles on pressure fluctuation characteristics in centrifugal pump

为了研究离心泵动静叶栅内固液两相流非定常流动所引起的压力脉动特性情况,采用大涡模拟与Mixture多相流模型相结合的数值模拟方法,运用滑移网格技术,对带有径向导叶的离心泵三维全流场进行了耦合计算.研究结果发现,对于清水相或固液两相,各监测点的压力系数均随着流量的增加而逐渐减小;脉动也随着流量的增加而逐渐趋于规律化.在动静叶栅交界面处,小流量工况下颗粒的存在增强了此处的高频压力脉动,而大流量工况下颗粒的存在削弱了此处的高频压力脉动;在导叶流道内,小流量工况下颗粒的存在削弱了此处的高频压力脉动,而大流量工况下颗粒的存在增强了此处的高频压力脉动;在蜗壳流道内,除了隔舌位置处,颗粒的存在已经不影响这一区域的压力脉动;在蜗舌位置处,颗粒的存在增强了蜗舌处的高频压力脉动.在动静叶栅交界面处,1.4Q时颗粒存在对压力脉动幅值影响最小,0.2Q时影响最大;在导叶流道内,1.4Q时颗粒存在对压力脉动幅值的影响最小,0.6Q时影响最大;在蜗壳流道内,1.0Q时颗粒存在对压力脉动幅值的影响最小,0.2Q时影响最大;在蜗壳蜗舌处,1.0Q时颗粒存在对压力脉动幅值的影响最小,0.2Q时影响最大.

To analyze the pressure fluctuation and the hydraulic force on the impeller between the rotor and stator in a centrifugal pump, the three-dimensional simulation was performed for the solid -liquid two-phase turbulent flow in a centrifugal pump with radial diffuser by the mixture multiphase model, the Large Eddy Simulation turbulence model and sliding mesh technology. The results indicate the pressure coefficients of both the water and solid - liquid flow decrease gradually with the increase of the flow rate; pulse also becomes regular gradually with the increase of the flow rate. On the interface of rotor and stator, the particle enhanced the high-frequency pressure fluctuation at the low flow rate, while at the high flow rate the particle weakened the high-frequency pressure fluctuation. In the rotor, the particle weakened the high-frequency pressure fluctuation at the low flow rate, while at the high flow rate, the particle enhanced the high-frequency pressure fluctuation. In the volute, the particle does not affect the pressure fluctuation, while in the tongue the particle enhanced the high-frequency pressure fluctuation. On the interface of the rotor and stator, the minimum impact of particles on pressure pulsation amplitude is 1.4Q, while the maximum is 0. 2Q; in the rotor, the minimum impact of particles on pressure pulsation amplitude is 1.4Q, while the maximum is 0. 6Q; in the volute, the minimum impact of particles on pressure pulsation amplitude is 1. 0Q, while the maximum is 0. 2Q; in the tongue, the minimum impact of particles on pressure pulsation amplitude is 1. 0Q, while the maximum is 0. 2Q.