Abstract When an axial flow pump operates at small flow rates, rotating stall may occur, which seriously restricts the pump performance and poses a great threat to the safe and stable operation of the whole system. The present work proposed a new groove flow control technology for the axial flow pump and studied its improvement effect and mechanism under stall conditions by numerical simulation. Results show that the groove flow control technology can significantly improve the hydraulic performance of the axial flow pump under stall conditions, with the pump head increment as high as 85.55% and the unstable region on the hydraulic performance curve was completely eliminated. In the inlet pipe region, it can effectively improve the bad flow state near the inlet of the impeller by increasing the axial velocity component and decreasing the velocity circulation dramatically. In the impeller region, the flow separation on the blade surface was improved and the cross-passage vortexes were suppressed, and the reasons were explained by analyzing the flow fields and pressure distributions in the representative grooves. In addition, compared with the diagonal groove (DG) scheme, the axial groove (AG) scheme showed better performance.

中文翻译：

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槽流控制技术改善轴流泵水力性能及内部流型的研究

摘要 轴流泵在小流量运行时，可能会发生旋转失速，严重制约了泵的性能，对整个系统的安全稳定运行构成极大威胁。本工作提出了一种新型轴流泵槽式流量控制技术，并通过数值模拟研究了其在失速工况下的改进效果及机理。结果表明，凹槽流量控制技术能够显着提高轴流泵在堵转工况下的水力性能，泵头增量高达85.55%，完全消除了水力性能曲线上的不稳定区域。在进水管区，通过增大轴向速度分量，大幅度降低速度环流，可以有效改善叶轮进口附近的不良流动状态。在叶轮区域，叶片表面的流动分离得到改善，交叉通道涡流得到抑制，并通过分析代表性凹槽中的流场和压力分布来解释原因。此外，与斜槽（DG）方案相比，轴向槽（AG）方案表现出更好的性能。