多级泵导叶径向力的数值模拟

Numerical Simulation of Radial Force in Guide Vane of Multistage Pump

为了降低多级泵导叶所受径向力,提高多级泵运行时的稳定性,采用SSTk-ω湍流模型对某多级离心泵末级导叶出口有压盖和无压盖两种情况分别进行全流道非稳态数值模拟,分析出口压盖对末级导叶非定常压力回收与总压损失、末级导叶叶片受力及作用在末级导叶上的径向力特性的影响。研究结果表明,数值模拟扬程预测结果与试验结果较吻合;由于动静干涉作用影响,末级导叶内总压损失、静压回收及作用在末级导叶上的径向力呈现周期性波动;当出口有压盖时,总压损失和静压回收波动明显减弱,末级导叶叶片合力矩较小,作用在末级导叶上的径向力和脉动幅值也减小,说明出口压盖可以减弱叶轮对导叶动静干涉的影响,改善作用在末级导叶上的径向力。

In order to reduce the radial force acting on the guide vanes of multistage pump and improve the stability of multistage pump during its operation,the SST k-ω turbulence model was used to simulate the unsteady flow in a multistage centrifugal pump with and without a cover at the outlet of the last guide vanes. The effects of the outlet cover on the unsteady pressure recovery and total pressure loss of the last guide vanes,the force exerted on the last guide vanes and the radial force acting on the last guide vane were analyzed. The research results show that the predicted result of head by numerical simulation was in good agreement with the test result. Due to the influence of interference of the moving and fixed blades,the total pressure loss of the last guide vanes,static pressure recovery and the radial force acting on the last guide vanes exhibit periodical fluctuation. For the pump with a cover at the outlet,the total pressure loss and static pressure recovery fluctuation were obviously weakened,the resultant torque of the last guide vanes was relatively small,and the radial force acting on the last guide vanes and pulsation amplitude were also reduced,indicating that the outlet cover can reduce the influence of the impeller on the moving and fixed vane interference and improve the radial force acting on the last guide vanes.