分流叶片对高速井泵压力脉动的影响

针对高速井泵采用分流叶片设计带来的稳定性问题,运用Creo3.0软件建立了叶轮、导叶等关键零件的三维模型;在CFX数值模拟数据与外特性试验数据吻合较好的基础上,将分流叶片的进口直径d₁与叶轮外径D₂的比值定义为一个表达分流叶片综合特性参数的量纲一化系数σ.σ分别取值0.60,0.62,0.65,设计分流叶片长短不同的3个叶轮方案,且对各方案的动静干涉区域进行了详细的压力脉动数值模拟计算及分析.结果表明:压力脉动幅值大小与监测点和交界面的径向距离有关,径向距离越大,压力脉动幅值越小;各监测点压力脉动随分流叶片长度的减小逐渐减弱,当分流叶片长度减小到某一临界值以后,压力脉动基本保持不变;当σ=0.62时,压力脉动幅值较小,脉动周期清晰;除中流线上的监测点以外,各监测点压力脉动主频受叶轮叶频的影响较大,分流叶片对中流线上监测点的压力脉动影响较大.

Influence of splitter blade on pressure pulsation of high-speed well pump

Aiming at the stability problem of high-speed well pump by using splitter blade design,three-dimensional models of key parts such as impeller and guide vane were established by using Creo3.0 software.Based on the good agreement between the CFX numerical simulation data and the hydraulic characteristic experimental data,the ratio of the inlet diameter of the splitter blade d1 to the outer diameter of the impeller D2 was defined as a dimensionless coefficientσwhich expressed the comprehensive characteristic parameters of the splitter blade.Three impeller schemes with different lengths of splitter blades were designed and the valueσwas selected 0.60,0.62 and 0.65 respectively.The detailed numerical simulation and analysis of pressure pulsation for the dynamic and static interfe-rence regions of each scheme were carried out.The results show that the amplitude of pressure pulsation is related to the radial distance between the monitoring points and the interface,and the larger the radial distance,the smaller the amplitude of pressure pulsation.The pressure pulsation of each monitoring point decreases with the decrease of the length of splitter blade.When the length of splitter blade is reduced to a critical value,the pressure pulsation is basically unchanged.Whenσ=0.62,the pressure pulsation amplitude is small,and pulsation cycle is clear.Except for the monitoring point on the middle streamline,the main frequency of pressure pulsation of each monitoring point is greatly influenced by impeller blade frequency.The splitter blade has great influence on the pressure pulsation of monitoring point on the middle streamline.