进气畸变及非轴对称端壁造型对紧凑型压气机中介机匣性能的影响

Effects of inlet distortion and non-axisymmetric endwall modeling onperformance of compact compressor intermediate duct

为掌握畸变进气下非轴对称端壁造型对大径向落差长度比紧凑型压气机中介机匣气动特性的影响机制,采用数值模拟方法研究了畸变进气条件下中介机匣的流动特性,并进一步探索了轮毂非轴对称端壁造型对中介机匣内部流动结构和节流特性的影响。结果显示:进气畸变下中介机匣出口流场高总压损失与畸变主要来源于轮毂表面附面层分离产生的旋流和支板角区分离的共同作用。采用提出的基于三角函数的非轴对称端壁造型方法可有效消除轮毂表面的分离螺旋节点和支板角区分离,使中介机匣性能得到明显提升,总压损失系数降低约11.4%,且畸变进气下轮毂端壁造型对中介机匣节流特性的影响规律与均匀进气不同。

To obtain the influence mechanism of non-axisymmetric endwall contouring(NAEC)on the aerodynamic characteristic of a compressor intermediate duct(CID)with large radius change to length ratio under inlet distortion,on the basis of investigating the flow characteristic under inlet distortion,the effects of hub NAEC on the internal flow structure and throttling characteristic of the CID were further explored with numerical method.The results showed that the high total pressure loss and the outlet flow distortion of the CID under inlet distortion were mainly caused by the combined action of the swirl generated by the hub boundary layer separation and the strut corner separation.The proposed NAEC method based on trigonometric function can effectively eliminate the spiral separation nodes on the hub and the strut corner separation,which improved the CID performance significantly,and the total pressure loss coefficient decreased by about 11.4%.In addition,the influence of NAEC on the throttling characteristic of the CID under inlet distortion was different from that of clear inlet condition.