【摘要】 为了探究叶栅端部二次流动结构及损失产生机制,对低速透平叶栅气动特性进行实验测量,结合数值模拟计算对透平端部二次流动结构及损失来源进行分析,通过分析通道内部熵产率分布,研究流动结构与不可逆损失之间的关系。结果表明,在所研究工况条件下,叶栅端部的二次流动结构主要源自来流边界层在前缘及通道内的三维分离现象,分离形成以马蹄涡、壁面涡以及通道涡为主导的涡系结构。端部二次流动损失主要来源于马蹄涡两分支、壁面涡和通道涡等漩涡自身的耗散,以及马蹄涡压力面分支与壁面涡合并成为通道涡时剧烈掺混引起的耗散。研究成果可为抑制端部二次流动及损失提供参考。更多还原

【Abstract】 To investigate the mechanism of the secondary flow loss in turbine cascade endwall,the aerodynamic characteristics of low speed turbine cascade was measured,and the endwall secondary flow structure in the passage and the cause of loss were analyzed using CFD method.The relation between flow structure and the irreversible loss was studied based on analysis of entropy generation rates in the passage.The results showed that 3D separation of the incoming flow boundary layer in the leading edge and passage was mainly caused by endwall secondary flow structure in cascade,and the horseshoe vortex,surface vortex and passage vortex were the main types of vortex system.The loss of endwall secondary flow was generated by the dissipation of horseshoe vortex,surface vortex and passage vortex,and also by the dissipation in passage vortex formed with the mixing of the pressure side in horseshoe vortex and surface vortex.The study results can provide reference for investigation on the reduction of endwall secondary flow and its loss.更多还原