A Behavior of the Diffuser Rotating Stall in a Low Specific Speed Mixed-Flow Pump
A Behavior of the Diffuser Rotating Stall in a Low Specific Speed Mixed-Flow Pump
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DOI：
10.5293/ijfms.2009.2.1.031
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发表时间：
2009-03
影响因子：
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通讯作者：
Masahiro Miyabe;A. Furukawa;H. Maeda;Isamu Umeki;Y. Jittani
中科院分区：
文献类型：
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作者：
Masahiro Miyabe;A. Furukawa;H. Maeda;Isamu Umeki;Y. Jittani
研究了具有正斜率水头流量特性的低比转速混流泵的流动不稳定性。根据静压测量，发现叶片扩压器中的旋转失速发生在最佳效率点 (BEP) 流量的约 65% 处。为了研究流场，进行了动态粒子图像测速（DPIV）测量和数值模拟。因此，扩压器旋转失速甚至可以通过计算流体动力学 (CFD) 进行模拟，并且计算出的周期性流动模式与 DPIV 测量的流动模式非常吻合。结果表明，扩压器叶片吸力面前缘产生的周期性大规模回流导致了不稳定。此外，扩压器叶片前缘处强涡流的增长引起从扩压器出口到入口的强烈回流。一个失速单元的尺寸覆盖了四个通道，总共十三个叶片通道。
The flow instability in a low specific speed mixed-flow pump, having a positive slope of head-flow characteristics was investigated. Based on the static pressure measurements, it was found that a rotating stall in the vaned diffuser occurs at about 65% flow rate of best efficiency point (BEP). A dynamic Particle Image Velocimetry (DPIV) measurement and the numerical simulations were conducted in order to investigate the flow fields. As a result, the diffuser rotating stall was simulated even by Computational Fluid Dynamics (CFD) and the calculated periodic flow patterns agree well with the measured ones by DPIV. It is clarified that a periodical large scaled backflow, generated at the leading edge of the suction surface of the diffuser vane, causes the instability. Furthermore, the growth of the strong vortex at the leading edge of the diffuser vane induces the strong backflow from the diffuser outlet to the inlet. The scale of one stall cell is covered over four-passages in total thirteen vane-passages.