Based on the RNG k - ε turbulence model and Rayleigh - Plesset cavitation function, three dimensional turbulent flow fields in centrifugal pump with inducer were calculated and analyzed numerically. The results showed a good prediction of the head drop for five flow rates. The hydrodynamic mechanism of the head drop was investigated through a local and global study of the flow fields. It was found that head began to approximately drop when the cavitation sheet reached the throat between two adjacent blades. The total pressure breakdown caused by cavitation firstly occurred in the upstream region of the impellers, then progressive decreased as the pressure rose in the whole blade-to-blade passage. Meanwhile, the cavity increased the total pressure of local regions, which would move downstream by the development of cavitation.%以空化条件下离心泵的扬程下降为切入点,基于RNGk -ε湍流方程和Rayleigh-Plesset空化模型研究带诱导轮的离心泵空化流动,获得了空化条件下离心泵流道的空泡分布及扬程下降规律,分析结果表明,空泡发展至诱导轮的喉部时,扬程开始下降；随着压力的降低,空泡首先出现在叶轮进口,并逐步发展至整个流道,进而影响离心泵的内部流动及能量转换；空化同时会引起局部流道的压增现象,压增的位置随空化强度的增大向下游流道移动.验证了诱导轮可以改善泵的空化性能,它能抑制空泡在主叶轮内的扩散,使空化仅造成主叶轮叶片进口处压力的缓慢下降,而主叶轮的扬程并未明显下降.
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