叶片数对微型斜流叶轮性能的影响

采用计算流体力学软件NAPA对叶片数不同的跨声微型斜流叶轮流场、性能进行了模拟,研究表明随着叶片数的增加,叶片载荷减小,叶背分离减小,叶片通道内流动改善,但叶片进口低压区域占叶片通道的比例增大,当叶片数增加到一定程度时主叶片不能全程加载.随叶片数的增加叶轮工作特性曲线左移的同时先上移后下移,通过与常规离心压气机最佳叶片数研究结果的对比表明,低雷诺数、微尺度效应及叶片占通道比例大使所研究微型斜流压气机的最佳叶片数略低于已有经验. 

Effects of blade number on performance of micro slope impeller

The results of a study for identifying optimum blade number of a transonic micro slope impeller with splitters were presented.An in-house-developed Navier-Stokes flow code was applied to the study.By increasing the blade,the blade load and separation on suction surface was decreased,and the internal flow was improved,but the low pressure zone was expanded in the entryway.In the event of excessive number of the blades,the full blade cannot work from the leading edge to the trail edge.Along with the augment of the blade number,the impeller performance curves move up and then down.As compared with the experience gained in the study of normal centrifugal compressor,the optimal blade number of the micro impeller is lesser.The lower Reynolds number,the effects of micro-scale and the biggish relative thickness of blade are contributing factors to produce the difference in optimal blade number.