凹槽结构对离心泵空化特性的影响

Influence of cavitation characteristics of groove structure for centrifugal pump

以低比转速离心泵为研究对象,提出一种叶片前缘布置凹槽结构的空化抑制方法.结合修正的SST k-ω湍流模型和Z-G-B空化模型对离心泵进行数值模拟,并将试验与模拟进行对比分析.结果发现:凹槽结构提升了离心泵的断裂扬程,降低了临界空化余量;在不同的空化阶段降低了漩涡强度,优化了周围流场的流动状态,诱发相对高压并改善涡量场;减少了各空化余量下离心泵的空泡体积,降低了多个监测点压力脉动主频幅值.凹槽结构有效限制离心泵空化发展,使离心泵的运行更加稳定.

Taking the low specific speed centrifugal pump as the research object,and a method to suppress cavitation by arranging a groove structure on the leading edge of the blade was proposed.The modified SST k-ωturbulence model and the Zwart-GerberBelamri(Z-G-B)cavitation model was combined to perform numerical simulations of the centrifugal pump,and the simulations were compared with experimental results.The results show that the centrifugal pump and reduces the critical cavitation margin.At different cavitation stages,the vortex intensity is reduced,the flow state of the surrounding flow field is optimized,relative high pressure is induced,and the vorticity field is improved.The bubble volume of centrifugal pumps under various cavitation margins is reduced,and the main frequency amplitude of pressure pulsation at multiple monitoring points is reduced.The groove structure effectively limits the cavitation development of the centrifugal pump,making the operation of the pump more stable.