不同工况下轴流泵转子径向力及其压力脉动分析

【目的】研究轴流泵转子所受径向力及内部压力脉动。【方法】采用试验以及ANSYS CFX定常计算的方法,研究了轴流泵的外特性;采用ANSYS CFX软件对轴流泵内部流场进行了非定常计算,研究了不同流量工况下轴流泵内部转子径向力的分布情况及内部不同监测点压力脉动的时域和频域特性。【结果】(1)数值计算的外特性结果与试验结果的趋势基本吻合,数值计算具有较高准确度;(2)转子运动时,内部流场关于转动中心呈现不对称性;(3)3种流量工况下径向力的分布均呈现一定的周期性,小流量工况下瞬态径向力最不稳定,波动较大,设计流量工况下瞬态径向力较小,大流量工况呈现较好的平衡状态;(4)不同流量工况下压力脉动受叶片数影响,主要以叶频为主,且随着频率的增加,压力脉动逐渐减小,说明低频信号是引起压力脉动的主要原因,从整体来看,各监测点压力系数随着流量幅值的增大而逐渐减小,但轮缘进口处变化较快,说明轮缘进口压力脉动受流量变化影响最大。【结论】轴流泵内部转子径向力随流量的增大趋于稳定,不同流量下内部不同点的压力脉动存在明显差异。

Analysis of Rotor Radial Force and Pressure Fluctuation of Axial Flow Pump Water Different Flow Conditions

【Objective】Study the unsteady flow characteristics of axial flow pump.【Method】Using ANSYS CFX software and external characteristics of the experiment method, the external characteristics of axial-flow pump,the distribution of rotor radial force under different flow conditions, and the influence of different flow conditions on pressure pulsation were analyzed.【Result】(1)Numerical results of the external characteristics matched the test results and the trend was the same, numerical calculation with high accuracy;(2)The distribution of radial force under certain flow conditions showed some periodicity. There were four peaks in one cycle, the same as the number of blades. When the flow rate was large, the radial force fluctuated less;(3)Under different flow conditions,the blade passing frequency dominated. The low frequency signal was the main reason causing the pressure pulsation in design condition. The rim inlet was greatly affected by the flow variation. On the whole, the pressure pulsation decreases with the increase of flow rate.【Conclusion】The radial force variation of the internal rotor of the axial flow pump tends to be stable with the increase of the flow rate. There are significant differences in the pressure pulsations at different internal points under different flow rates.