中文摘要：

为了研究离心泵发生空穴后的工作性能，将Singhal空穴模型和Mixture多相流模型相结合，运用RNGk-ε湍流模型和SIMPLE算法对离心泵的三维流场进行计算流体动力学数值模拟，并预测其性能曲线。研究结果表明，压力自叶片工作面的根部向尾部逐渐增大，然后从背面的尾部向根部不断下降，在入口端容易发生空穴。空穴的临界条件为泵入口压力58104Pa或出口压力187792Pa。当泵发生空穴时，叶轮内的流线偏离叶片型线，并在流量下降时出现大尺度漩涡，造成泵的扬程和效率急剧下降。在设计流量下，一定程度的空穴并不引起泵效的大幅下降，当泵出口压力超过145kPa时，空穴造成的泵效下降率小于1．97％。

英文摘要：

To study the performance of centrifugal pump under cavity condition, the Singhal cavity model and Mixture muhiphase flow model are combined to numerically simulate the flow dynamics of the three-dimensional flow field by using the RNG K-ε turbulent model and SIMPLE algorithm. Then, the performance of the centrifugal pump is predicted. Research results show that the stresses increase gradually from working face of blade root to tail, and decrease gradually from the back of the blade tail to the back of the blade root. Cavity is most likely to occur at the inlet end. Inlet pressure of 58. 104 kPa or outlet pressure of 187. 792 kPa is the critical conditions of cavi- ty. When cavity occurs, the flow line inside the impeller deviates from the blade type line, and result in a large scale vortex flow when the flow rate down, causing a sharp drop in pump discharge effect and efficiency. Under the design flow, the degree of cavity could not cause sharp drop of pump efficiency. When the pump outlet pressure is more than 145 kPa. Dump efficiency decline rate caused bv cavity is less than 1.97%.