前缘复合改型在压气机平面叶栅中的应用初探

Preliminary Investigation of Elliptic Tubercle Leading Edge Blade in Planar Compressor Cascade

为了探究同时应用不同前缘改型对压气机叶栅的影响,以DMU37动叶5%叶高处叶型的平面叶栅为原型,采用数值计算方法,探究4种椭圆形前缘改型及4种椭圆鼓包复合改型对叶栅流场及性能的影响,考虑的主要影响参数分别为椭圆长短轴比和鼓包波幅。结果表明:-6°～+4°冲角时,椭圆形前缘方案可不同程度地降低前缘吸力峰及总压损失系数,特别在正冲角条件时改善效果更好;长短轴之比为4的椭圆形前缘方案综合性能最好,主流区吸力峰高度降低56.3%,+4°冲角时,总压损失系数和可比原型叶栅降低5.8%;0°冲角下,椭圆鼓包复合改型的损失相比原型叶栅均有所增大;+4°冲角时,各椭圆鼓包复合改型方案均能有效降低损失,总压损失系数最多可比原型叶栅降低7.5%,表明椭圆鼓包复合改型在+4°冲角时可以提高叶栅气动性能。

In order to investigate the effects of plural leading edge modifications simultaneously applied to compressor cascade,a planar compressor cascade which shaped by the blade profile of DMU37 at 5%span was selected as the baseline.A numerical simulation for different leading edge cascade,which included four elliptic leading edges and four elliptic tubercle leading edges,was carried out to investigate the influence on flow field and aerodynamic performance.Length to short axis ratio of ellipse and amplitude of tubercle were considered as the main parameters.Results show that elliptic cascade can variously decrease suction spike and total pressure loss coefficient at incidence of-6°to+4°,especially at positive incidence.A decrease in suction spike of 56.3%and loss coefficient of 5.8%at the incidence of 4°is achieved for elliptic cascade with the best comprehensive properties when its length short axis ratio was four.Elliptic tubercle leading edge cascade shows an increase in loss coefficient at incidence of 0°,however,it effectively decreases loss at incidence of+4°.The highest reduction of total pressure loss coefficient can reach up to 7.5%,which means elliptic tubercle leading edge can improve the aerodynamic performance of cascade.