不同宽度无叶扩压器与半开式离心叶轮匹配特性数值模拟  

Numerical Simulation on Match Effects of Vaneless Diffuser and Unshrouded Centrifugal Impeller

作　　者：邵栋[1] 王彤[1] Shao Dong Wang Tong(School of Mechanical Engineering, Shanghai Jiao Tong Universit)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《风机技术》2016年第4期15-21,27,共8页Chinese Journal of Turbomachinery

基　　金：国家自然科学基金资助项目(51276108)

摘　　要：考虑到扩压器与叶轮的匹配特性,本文对不同宽度扩压器的半开式离心叶轮流道的性能与流动结构进行了分析。通过数值建模与全工况的性能计算,对比了数值计算性能与实验性能,验证了数值方法的可靠性。在此基础上,调整扩压器宽度,发现适当减小扩压器宽度可以使叶轮出口流动趋向均匀,进而抑制扩压器盖侧回流,改善整个流道的性能;尤其是在小流量工况下,可以有效提高离心叶轮流道的效率和压比。同时发现,不同宽度扩压器对叶轮叶顶泄漏流有一定的影响,进而影响叶轮的性能。Concerning about the match effects of the vaneless diffuser and the centrifugal impeller, the effect of matching diffusers with different width on the performance and flow characteristics of the flow passage were numerically simulated. The numerical model was set up and the working performance was got. By comparing with the experimental performance, the numerical method was proved to be reliable. Therefore, the simulation was carried out with impeller passage matching different width of vaneless diffuser. It is found from the simulation result that there is flow separation region near the shroud area in diffuser. The region would influence the performance of the flow field and may expand to the impeller outlet at near stall condition. In fact, by reducing the diffuser width, the uniformity of the radial velocity distribution at the impeller outlet would be improved. Thus, the separation region could be suppressed by reducing the diffuser width.Besides, the performance of the passage would be improved as well as the tip leakage flow of the impellerwould be suppressed from near stall to the near design condition by reducing the diffuser width.

关 键 词：半开式叶轮 无叶扩压器宽度 叶顶间隙流动 

分 类 号：TH452[机械工程—机械制造及自动化] TK05[动力工程及工程热物理]