粗糙度对超高负荷低压涡轮边界层影响

Effects of Roughness on Boundary Layer of Ultra-High-Lift Low-Pressure Turbine

关键词:  被动控制  分离泡  粗糙度  叶型损失 

Key words:  Passive control  Separation bubble  Roughness  Profile loss

摘要:

基于IET-LPTA叶型研究了被动控制中的粗糙度对分离转捩的影响,以寻求一种优化的粗糙度布置方式来减小叶型损失。研究以CFX数值模拟为主,对数值结果进行试验验证。主要考察了不同粗糙高度及不同粗糙度布置位置对叶型损失的影响,提出了变粗糙高度的优化布置方案,并使用间歇因子、位移厚度、动量厚度、形状因子、湍流度等特征参数分析了粗糙度控制分离的机理。研究发现粗糙度对减小叶型损失,推迟开式分离泡的出现有显著作用,同时变粗糙高度结合前缘至转捩点的布置方式能够更好地抑制分离,减小叶型损失。 

Abstract:

In order to find an optimum roughness disposal to reduce the profile loss.the effects of passive control of roughness on the separation bubble was studied based on the IET-LPTA airfoil. CFX was used to perform the numerical simulation. Moreover, the numerical results were verified by experiment. The effects of different roughness height and different roughness layout position on the airfoil loss were studied, meanwhile the variable roughness height was examined to reduce the airfoil losses. The intermittency factor, displacement thickness, momentum thickness, shape factor, and turbulence intensity were used in the analysis of the separation control principle. The roughness plays a significant role to reduce airfoil losses and postpone the appearance of open separation bubble. Variable roughness height combined with the disposal between leading edge and transition onset could control separation and reduce the profile loss.