Numerical prediction of critical cavitation number in pump-turbine
Hao Zongrui1, Liu Jintao2, Wang Leqin2
1.Institute of Oceanographic Instrument, Shandong Academy of Science, Qingdao, Shandong 266001, China; 2.Institute of Process Equipment, Zhejiang University, Hangzhou, Zhejiang 310027, China
Abstract：The hydraulic performance and internal flow in a pump-turbine model were analyzed under different cavitation numbers to study effects of the coefficient on unsteady flow in the model by using the SST k-ω turbulence model. The results show that cavitation number can alter the flow pattern in the pump-turbine and the critical cavitation number reflects the energy performance of a pump-turbine. The head of pump-turbine decreases and the efficiency rises at cavitation inception; with development of the cavitation, the head increases considerably, while the efficiency decreases quickly. The cavities are located at the blade suction side near the runner outlet and ring. The change of cavitation number has less effect on the instability of flow in the pump-turbine runner only. If cavitation number is larger, the head of pump-turbine will remain unchanged essentially. Moreover, the head decreases slightly with decreasing cavitation number when cavitation number is in the range of 0.075-0.150. However, the head increases with decreasing cavitation number as the coefficient is less than 0.075.
郝宗睿, 刘锦涛, 王乐勤. 水泵水轮机临界空化系数的数值预测[J]. 排灌机械工程学报, 2013, 31(9): 774-777.
Hao Zongrui, Liu Jintao, Wang Leqin. Numerical prediction of critical cavitation number in pump-turbine. Journal of Drainage and Irrigation Machinery Engin, 2013, 31(9): 774-777.
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