一种叶顶叶栅结构对压气机间隙流动的影响

Influence of tip cascade structure on clearance flow in a compressor

为减小压气机间隙流动带来的流动损失,提出了一种新的叶顶结构,即在常规叶片叶顶上构造出由数个小叶片组成的叶栅.通过对具有该结构叶片的三维流场进行数值模拟,分析了端壁移动对压气机间隙流场的影响.结果表明:该结构明显改善了叶顶附近的流动状况,从泄压和导流两方面抑制了叶顶附近流体从压力面向吸力面的泄漏,有效削弱泄漏涡的强度,进而减小泄漏涡扩散带来的损失,提高了压气机气动性能,相比常规叶片叶栅出口总压损失系数减小达1.158%.

A new tip cascade structure, consisting of some small blades on top of the conventional blades, was proposed to reduce the tip clearance flow loss in compressor. The numerical simulation was carried out to investigate influence of the tip clearance on the three dimensional flow field in compressor cascades with moving end-wall. The simulation results show that the structure can improve the tip clearance flow condition. The leakage flow from pressure side to suction side on top of the blade is suppressed in terms of pressure relief and diversion. The strength of the leakage vortices is weakened effectively, and the diffusion loss of leakage vortices is reduced, so the aerodynamic performance of compressor will be im proved, and the total pressure loss coefficient decreases by 1. 158% compared with conventional blade in cascade exit.