混流泵启动过程非稳态空化的试验研究

为了分析混流泵启动过程瞬态扬程理论模型的适用性及非稳态空化过程,通过高速摄影和压力测量试验,探讨不同空化数、不同流量工况下启动过程中叶顶区空化状态特性。试验研究结果表明,已有理论模型可应用于混流泵启动过程,同时验证试验结果准确性。在启动过程中,空化最先发生在叶顶区域头部。当启动完成时,叶顶空化区域可分为两部分,一部分为出现在叶顶区的三角形的空化云团;另一部分为刮起涡空化。在同一流量工况下,随着空化数降低,垂直空化涡会在启动过程中出现并且发展。在同一空化数下,随着流量减小,垂直空化涡延迟出现,并且空化区域减小。

Tests for unsteady cavitation of mixed flow pump during start-up

In order to analyze applicability of the transient water lift theoretical model and unsteady cavitation process in start-up process of a mixed flow pump,high-speed photography and pressure measurement tests were conducted to investigate cavitation characteristics in blade tip region of the mixed flow pump under different working conditions of cavitation number and flow rate.The test results showed that the existing theoretical model can be applied to the start-up process of mixed flow pump,and the correctness of test results is verified;in start-up process,cavitation occurs firstly in blade tip region;when start-up is completed,the blade tip cavitation region can be divided into two parts,one is a triangular cavitation cloud cluster appearing in blade tip region,the other is a blowing vortex cavitation;under conditions with the same flow rate,with decrease in cavitation number,vertical cavitation vortex can appear and develop in start-up process;under conditions with the same cavitation number,with decrease in flow rate,vertical cavitation vortex occurring delays and cavitation area shrinks.