非轴对称端壁在对转压气机中的应用

The Application of Non-Axisymmetric Endwall in a Counter-Rotating Compressor

非轴对称端壁是降低叶栅二次流损失提高叶轮机械性能的有效途径，本文采用数值优化算法对某对转压气机出口导叶机匣进行非轴对称端壁优化造型，并对非轴对称端壁造型前后对转压气机流场结构进行对比分析。结果表明：非轴对称端壁造型可明显提高对转压气机性能，出口导叶总压损失系数降低3．3％；端壁区域流动状况得以改善，端壁区域横向二次流明显降低，出口导叶叶尖前缘气流分离被有效遏制，叶尖吸力面旋涡区域被压缩至前缘局部；非轴对称端壁造型后导叶70％-100％叶展总压损失系数均明显减小。

Non-axisymmetric endwall contouring is one of the main methods to control secondary flows. The purpose of the paper is to improve the efficiency and reduce the secondary loss of an axial flow counter-rotating compressor. The shroud endwall of the outlet guide vane （OGV） of the counter-rotating compressor is optimization designed by using non-axisymmetric endwall. The flow fields of the compressor with annular endwall and contoured endwall are compared. The results show that non-axisymmetric endwall can effectively improve the performance of the compressor. A 3.3% reducing of total pressure loss is seen in the OGV. The transverse flows near the shroud endwall are reduced obviously. The separated flow area near the leading edge of OGV of contoured endwall is less than that of annular endwall. The total pressure loss coefficients at 70%-100% span is significantly reduced with contoured endwall.