【作者】 钟兢军；

【导师】 王仲奇； 苏杰先；

【作者基本信息】 哈尔滨工业大学 ， 热力叶轮机械， 1996， 博士

【摘要】 现代航空工业的发展，要求不断提高航空发动机的性能，其中压气机性能的改善起着十分关键的作用。因此，研究压气机叶栅内真实流动的结构和机理，探索降低做为叶栅中主要能量损失的二次流损失的方法和途径是非常必要的。 本文对具有常规直叶片、正倾斜叶片、正弯曲叶片、反弯曲叶片和S型叶片的压气机平面扩压叶栅，在低速大尺寸风洞上进行了实验研究。在零冲角、正冲角和负冲角下利用静压测孔和五孔束状探针对叶栅壁面静压和叶栅出口流场进行了详细的测量，并在零冲角下进行了流场显示。实验给出了五种叶栅零冲角和变冲角下的特性。实验结果表明，常规直叶栅的通道涡较强，叶栅出口集中脱落涡和角区分离泡的存在，造成了叶栅两端区较高的二次流损失。在正倾斜叶栅中，根部区域通道涡加强，角区的分离消失，吸力面上气流分离由鞍点／螺旋点分离转变为鞍点／结点分离，根部区二次流损失降低；顶部区域由于低能流体的大量集聚，分离和回流相当严重，高损失区扩大，叶栅的总损失提高。正弯曲叶栅中，建立了沿叶栅的中部压力低而两端压力高的“C”型压力分布，两端区通道涡加强，角区分离消失，上下两个集中脱落涡向叶栅中部汇合并出现旋涡的破裂，叶栅中部二次流损失有所提高，在正冲角下叶栅总损失有所降低，而零冲角和负冲角下叶栅总损失有所提高。对反弯曲叶栅，叶栅通道涡较直叶栅有所减弱。虽然两端的角区分离有所加大，但集中脱落涡由于流线的收缩而减弱为尾缘出口脱落涡且汇聚在叶栅中部，通道涡和脱落涡破裂消失，叶栅二次流损失降低，叶栅总损失在所有冲角下与直叶栅相比均得到降低。S型叶栅表现出正弯曲叶栅和反弯曲叶栅的一些特点，损失沿展向分布较为均匀，但叶栅总损失未得到降低。 此外，本文研究了采用弯曲叶片后，扩压叶栅气动特性与叶栅稠度的关系。实验结果表明，随叶栅稠度的增加，叶栅损失在大部分冲角下呈增高趋势。在正弯曲叶栅中，对应最小损失的冲角出现在正冲角下，且低损失系数区增宽；在反弯曲叶栅中，对应最小损失的冲角为负冲角。为了降低损失，正弯曲叶更多还原

【Abstract】 In this paper ,a detailed experimental investigation has been carried out in a low speed,large scale wind tunnel with five compressor cascades composed of conventional straight blades,positive leaned blades,positive curved blades,negative curved blades and S-type blades respectively. The blade surface, endwall static pressures and cascade exiting flow fields are measured with wall static pressure tappings,a small size five -hole probe at zero,positive and negative incidences and the flow visualizatons conducted at zero incidence. It is shown that the passage vortices are quite strong in the straight blade cascade. Due to the existence of concentreted shed vortices and corner vortices,the secondary loss at the two ends is much higher. On the acute side of the positive leaned blade cascade, the passage vortex is strengthened, the corner stall disappears and the secondary loss decrease. The topological structure on the suction surface of leaned blade acute side changes from the saddle/spiral node pattern separation to saddle /separation node pattern separation. On the obtuse side, the separation and the reverse flow become much stronger. And due to the migration and accumulation of low energy fluids the regions with high energy loss are enlarged . The beneficial effect on performance of reducing the secondary loss on the acute side is offset by an increase on the obtuse side ,while the total loss of the positive leaned blade cascade increases. Blade positive curving introduces the effect of positive lean on the two ends of the cascade, which enhances the passage vortices and makes the corner stall disappear. In this cascade, the "C" type static pressure distribution spanwise is established . The concentrated shed vortices move and converge towards the midspan and separate there. The secondary loss at the midspan increases. The total loss of the positive curved blade cascade does not decrease at zero and negative incidences compared with the straight blade cascade. Some gains in performance appear at positive incidences. In the cascade with negative curved blades,the passage vortices are weakened. Although the corner stall is somewhat intensified,the breakdown of the passage vortices and shed vortices disappears, and the concentrated shed vortices are weakened to be trailing edge shed vortices . Therefore ,the secondary loss更多还原