分流叶片对离心泵内部非定常流动特性的影响

采用Ansys-CFX软件对5个具有不同分流叶片进口直径、不同分流叶片周向偏置度的叶轮方案进行全流场非定常数值模拟,分析了有、无分流叶片以及不同分流叶片设计对叶轮进口、蜗壳出口及叶轮-蜗壳交界面处压力脉动特性的影响规律.结果表明：分流叶片有利于降低叶轮进口压力且提高蜗壳出口压力,从而提高泵的扬程,带分流叶片设计方案的扬程比没有分流叶片设计方案提高2%～12%,但不同分流叶片设计方案的扬程绝对值差异不大;分流叶片有利于减小叶轮进、出口处的压力脉动;有利于减小叶轮-蜗壳交界面处的压力脉动,从而改善叶轮出口的＂射流-尾流＂结构;不同分流叶片设计对扬程的影响趋势接近,但对非定常流动特性的影响不同,当分流叶片进口直径为106 mm且向长叶片背面偏置5°时,扬程最高,压力脉动最小;带偏置分流叶片设计方案的扬程略高于带不偏置分流叶片设计方案.

Influence of splitter blades on unsteady flow characteristics in centrifugal pump

Ansys- CFX software was adopted to simulate the unsteady flow field at different operating conditions in an entire centrifugal pump whose impeller was designed with and without splitter blades. To analyze the influence of design parameters of splitter blades on the unsteady flow field of the pump, the splitter blades were designed to have different inlet diameters and circumferential positions. The re- sults show that when splitter blades are added, the pump head increases by 2% - 12% and the pres- sure fluctuations at the impeller inlet, volute outlet and the interface of impeller and volute are re- duced, thus the splitter blades have improved the ＂jet-wake＂ flow structure. The influence of design parameters of splitter blades on the unsteady flow field in the pump is variable. When the inlet diame- ter of splitter blades is 106 mm and the blades are deviated to the suction side of the full length blades by 5 , the head is the highest and the pressure fluctuations are the lowest.