辐条控制技术对竖井贯流泵马鞍区水力特性影响的数值模拟

Numerical simulation of influence of groove control technique on saddle zone hydraulic characteristics for a shaft tubular pump

基于非定常雷诺时均(URANS)方法,采用曲率修正的SST k-ω湍流模型,对竖井贯流泵内部流场进行非定常计算,研究辐条控制技术对不同工况下竖井贯流泵水力性能以及水泵叶轮进口流场和压力脉动特性的影响。结果表明:在设计工况下,辐条控制技术对竖井贯流泵的水力性能和叶轮进口流场、压力脉动特性的影响不大;在马鞍区工况下,竖井贯流泵叶轮前进水流道的轴向速度降低,速度环量增大,并随着流量减小而产生大范围回旋流,造成进水流道堵塞,引起低频压力脉动幅值增大;辐条控制技术可有效抑制回旋流的强度,提高叶轮入流的均匀度,降低压力脉动幅值,有效改善竖井贯流泵马鞍区工况的水力性能。

To investigate the hydraulic characteristics of a shaft tubular pump,the flow field and the pressure fluctuations at the impeller inlet,numerical simulation based on URANS method and a curvature corrected SST k-ωturbulence model was used to simulate the unsteady internal flow field in a shaft tubular pump with and without the groove control technique.The results show that the groove control technique has little effect on the pump performance,the flow field and the pressure fluctuations under the design conditions.When the flow rate decreases to the saddle area,the axial velocity in the impeller inlet decreases and the velocity circulation increases.The backflow region is extended with a large scale,which causes blockage of the inlet and low frequency pressure fluctuations.The groove control technique can effectively suppress the backflow vortices,increase the flow velocity uniformity and decrease the amplitudes of pressure fluctuations,resulting in an efficient improvement for the hydraulic characteristic of a shaft tubular pump in the saddle zone working condition.