加环控制轴流风机叶顶间隙的分析与试验

Analysis and Test on the Performance of the Axial Fan with a Ring Near the Blade Tip on the Casing

轴流风机叶顶间隙复杂流动情况直接影响风机性能,本文以一款弯掠叶片轴流风机为研究对象,采用叶顶加环结构改变风机叶顶间隙。研究了叶顶加环对该风机性能的影响。对加环前后的轴流风机整机模型进行了稳态三维流场计算,给出了叶顶加环在不同工况下对风机内部流场的影响的细节,并对计算结果进行了实验验证。结果表明,采用叶顶加环的方法来改变叶顶间隙,能够有效地提升风机的全压以及全压效率。在设计工况下,加环结构有益于抑制叶顶间隙涡的形成。在偏大流量下,加环结构能有效减小叶顶间隙涡。对所加钢板环形成的冲击损失做了定性分析,结果显示,随着流量增大,冲击损失增加。

The complex flow in tip clearance directly affects the performance of axial fan.In this paper,the performance of axial fan with a ring near the blade tip on the casing was investigated.The three-dimensional flows ranging all regions for the axial fans with ring and without ring were computed.The simulation results showed detail internal flow in the different conditions,and they were also verified by the tests.The results showed that reducing the tip clearance by adding a ring near the blade tip on the casing could enhance the total pressure and total pressure efficiency effectively.In the design condition,the ring could inhibit the formation of the tip clearance vortex.In the large flow,the ring can reduce the tip clearance vortex effectively.In addition,the loss of confliction formed by adding a steel ring has been done a qualitative analysis,found that the loss of confliction increasing as the flow rate.