中文摘要：

为研究双吸泵在小流量工况下叶轮内部空化特性,同时进一步说明小流量工况相比于设计工况时的空化特性差异,结合均质两相流模型和SST k-ω湍流模型,对双吸泵小流量工况和设计工况下的全流道空化流场进行数值模拟,以分析不同流量工况下空化分布与发展情况,以及空化对各叶片载荷造成的影响。研究结果表明：适当减小双吸泵进口流量,有助于改善双吸泵的空化性能;在小流量工况下空化首先发生于叶片吸力面头部靠后盖板附近,而且此处的空泡体积分数最大,这一空化特征同设计工况有所差异;随着NPSH的降低,叶轮内空化不断加强,但是小流量工况下的空化强度始终不及设计工况;不同空化状态会导致叶片吸力面压力的变化,从而表现为叶片表面载荷分布的变化。

英文摘要：

In order to study the cavitation characteristics of the internal flow field in double suction centrifugal pump under small flow conditions and further demonstrate the difference from designed condition, we selected k - to SST turbulence model and homogeneous two - phase flow model to simulate the flow field, the turbulent flow field in the impeller of the double suction pump and the flow passage in the spiral case were obtained. The cavitation distribution and development under different flow conditions and the impact on the blade loading were analyzed. The results showed that the cavitation performance of the double - suction pump would be improved if the inflow decreases. Under the small flow condition, the cavitation occurs first at the head of the suc- tion side of the blade near the back cover, where the volume fraction is the largest. This is difference from the designed condi- tion. With the decrease of the NPSH, the cavitation inside the impeller was stronger, however, the cavitation under small flow is smaller than or equal to that under designed condition. Different cavitation situations lead to the change of the surface pressure of the suction side of the blade, which was represented as the variation of the blade loading distribution.