【摘要】 在高性能航空与民用燃汽轮机设计过程中,涡轮叶栅内部叶片表面边界层由层流向湍流的转捩始终得到设计者的关注,原因就在于叶片表面边界层流态与叶型损失密切相关。笔者在特定的低速来流条件下,采用多种剪敏液晶显示材料,深入研究了叶栅风洞中叶片表面边界层流态剪敏液晶显示技术,对美国联合技术公司(UTC)提供的涡轮叶栅进行了大量吹风实验,从实验拍摄的图像分析,证实了该项技术能够在一定范围内较为准确地探测叶片表面边界层转捩的发生。为从机理上更深刻地认识叶片表面粘性边界层转捩机制,笔者对来流马赫数和冲角对转捩过程的影响进行了分析。更多还原

【Abstract】 The problem of boundary layer transition to turbulence in turbine cascade flow environments remains of critical concern of designer of high performance gas turbines,since there is a very close connection between profile losses and the blade surface boundarylayer flow.The author investigated boundary layer transition visualization method on blade surface with shearsensitive liquid crystal coating in low speed turbine cascade wind tunnel.A series of wind tunnel tests were made on turbine cascade in NPU.Detailed discussion was made on the video images taken from experiments,which confirmed the validity of the visualization technique in boundary layer transition detection on blade surface.To realize the complex mechanism of boundary layer transition from laminar flow to turbulent flow,the effects of inlet flow Mach number and incidence angle on boundary layer transition were also discussed.更多还原