叶片背面不连续凸起对轴流泵空化的控制研究

Study on the Control of Cavitation of Axial Flow Pump With Discontinuous Bulges on the Back of Blades

为控制轴流泵空化的发生与发展,提出了一种在轴流泵叶片背面布置不连续凸起结构的方案。基于ANSYS CFX软件,对350ZQ-125-30型潜水轴流泵进行数值模拟,对比分析改进模型与原模型流道内压力、湍动能、空泡及流线分布的变化.结果表明,改进后叶片背面低压区域减小,工作面高压区域明显增大,临界空化余量降低;在空化的各个阶段空泡体积分数都有所减小,其中空化初生阶段最为明显,相比原模型减小了38.3%,有效地控制了空化的发生,空化性能明显提升;在空化发展阶段,凸起的存在能够有效阻挡回射流的冲击,控制了空泡的脱落,同时抑制了叶轮流道内梢涡空化的产生。

In order to control the occurrence and development of axial pump cavitation,a scheme for arranging discontinuous bulges structures on the back of axial flow pump blades was proposed.Based on ANSYS CFX software,the numerical simulation of the 350 ZQ-125-30 submersible axial flow pump was carried out to compare and analyze the changes of pressure,turbulent kinetic energy,cavitation and streamline distribution between the improved model and the original model.The results show that the low pressure area on the back of the blade is reduced,the high pressure area of the working face is increases obviously,and the critical cavitation margin decreases.The cavity volume fraction decreases in all stages of cavitation,especially in the initial stage of cavitation,which decreases by 38.3% compared with the original model,effectively controlled the occurrence of cavitation and the cavitation performance.At the stage of cavitation development,the existence of the bulge can effectively block the impact of the re-jet,control the drop of the cavity,and restrain the generation of tip vortex cavitation in the impeller channel.