To better reveal the mechanism of the rotor-stator interference between the impeller and the guide vane and the evolution process of the stall vortex under the part-load conditions, numerical simulation is carried out based on the DDES turbulence model, which can better capture vortex structure. And the pressure pulsation and the radial velocity distribution of the centrifugal pump are studied. The vortex structure and pressure fluctuation of pump internal flow field under part-load condition of Q = 0.4 Q_des are mainly analyzed. The analysis results show that the stall vortex is formed at the inlet of the impeller and evolves to the outlet of the impeller, the front cover to the rear cover according to the fluid flow direction, and then disappears. Besides, under the part-load condition, the vorticity of the impeller outlet is always obviously less than that of the impeller inlet as the flow rate increases. Due to the asymmetric action of the volute, the radial velocity distribution law of flow channel C1 is different from other flow channels at different blade heights. By analyzing the radial velocity, the phenomenon that the jet-wake flow impacts the guide vane with the rotation of the impeller is the main reason for the rotor-stator interference. And large radial velocity gradients appear at the front and rear cover plates, which will cause high energy loss and reduce pump efficiency. Besides, the conclusion can be drawn that the region with the strongest rotor-stator interference is the inlet region of the guide vane suction surface. It also occurs near the volute tongue but is lower due to the effect of the guide vane. This research may serve as a reference for the safe operation of centrifugal pumps under part-load conditions.

中文翻译：

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基于DDES湍流模型的离心泵部分载荷下非定常流动特性分析

为了更好地揭示叶轮与导叶之间的转子-定子干涉机理以及部分负荷工况下失速涡的演化过程，基于DDES湍流模型进行数值模拟，能够更好地捕捉涡流。结构体。并对离心泵的压力脉动和径向速度分布进行了研究。Q  = 0.4  Q _des部分负荷工况下泵内部流场的涡流结构及压力脉动主要是分析。分析结果表明，失速涡在叶轮入口处形成，并根据流体流动方向向叶轮出口、前盖向后盖演化，然后消失。此外，在部分负荷情况下，随着流量的增加，叶轮出口的涡量始终明显小于叶轮入口的涡量。由于蜗壳的不对称作用，流道C1的径向速度分布规律与不同叶片高度的其他流道不同。通过对径向速度的分析，喷射尾流随着叶轮的旋转撞击导叶的现象是转子-定子干涉的主要原因。前后盖板出现较大的径向速度梯度，这将导致高能量损失并降低泵的效率。此外，可以得出结论，转子-定子干涉最强的区域是导叶吸力面的入口区域。它也发生在蜗形舌附近，但由于导向叶片的作用而降低。该研究可为离心泵在部分负荷工况下的安全运行提供参考。