子午扩压对环形叶栅流道内旋涡发生和发展的影响

为了研究子午流道有较大扩压情况下,环形叶栅内集中涡系发生、发展的流动过程,详细测量了由栅前至栅后 1 2个横截面上气动参数沿节距和叶高的分布。试验结果表明:子午流道的较大扩压增厚了进口端壁附面层,因而加剧了鞍点分离并形成了高强度、大尺度马蹄涡压力侧与吸力侧分支。周围的大量低动量气体加强了两分支的组对效应,推迟了通道涡的形成与发展,通道涡的强度与尺度同样正比于流道的扩压度。在叶栅下游,由于径向正压梯度的影响,低能气体沿尾流区向轮毂输运,引起下通道涡的迅速消散与衰减。 

Effects of Meridional Divergence on Vortex Evolution in Annular Cascades

The flow process of concentrated vortex occurrence and development was investigated in the meridian with considerable divergence.The distributions of aerodynamic parameters along pitch and span in the 12 measurement sections were surveyed.The results show that the divergence of the diffused meridian passage thickens the inlet boundary layer,so saddle point separation intensifies,and pressure side and suction side branches of high-strength and large-scale horseshoe vortex are formed,low energy gas around them enhances the paired effect,delays the formation and development of passage vortex.The strength and scale of passage vortex are proportional to the divergent angle of the passage.Due to the influence of radial positive pressure gradient,low-energy gas moves along trailing area to hub.That causes rapid dissipation and weakening of downstream passage vortex.