凹型轴对称端壁造型在大安装角扩压叶栅中的应用研究

Application Study of Concave Axisymmetric Endwall Molding in a Compressor Cascade with High Stagger Angle

为改善大安装角扩压叶栅角区流动,应用轴对称端壁造型技术对其端区进行改型设计。采用数值模拟的方法探讨了凹型曲线覆盖长度以及深度对叶栅气动性能的影响,结果表明,在设计冲角以及负冲角下,采用合理的凹型端壁造型方案均可不同程度地降低叶栅端区流动损失和出口落后角度,但在正冲角下,端壁造型曲线选取不当将会提前促发角区失速,恶化端区流场。进一步将凹型轴对称端壁造型技术应用到1.5级压气机中,验证了此种改型方法的有效性,在保证工作范围基本不变的条件下,整机峰值效率提高了0.94%。

In order to improve the corner flow of a compressor cascade with high stagger angle, the concave axisymmetric endwall molding technology（CAEMT） was applied to redesign its endwall region. The numerical method was adopted to investigate the effects of covering length and covering depth of concave line on the aerodynamic performance of the compressor cascade. As a result,it is found that the different CAEMT schemes can decrease the endwall flow loss and outlet deviation flow angle of the cascade to different extend at negative and design incidences. However,the corner stall will be triggered early and endwall flow will be aggravated at higher positive incidence once improper endwall contouring line is implemented. The CAEMT is further applied into a 1.5 stage compressor to test its effectiveness and the peak efficiency of the compressor increased by 0.94%with a similar operating range.