摘要
采用大涡模型(LES)模拟了圆形气膜孔和锥形角γ=30°扇形孔在吹风比M=1.0时不同截面上的涡量等值线以及分布特征随时间的变化过程。结果表明:对称面的正反旋涡和垂直截面的马蹄形涡的两翼交替周期性地脱落成新的涡,同一截面扇形气膜孔旋涡生成和脱落的时间比圆形气膜孔的短,冷气射流与主气流掺混剧烈,带走的能量较多,所以壁面的冷却效率高;反向旋涡对气膜冷却流场有重要影响,在同一截面圆形孔的反向涡旋对(CVP)要比扇形孔的大,且涡心位置要比扇形孔的高,因此圆孔对壁面的冷却效果要比扇形孔的差。
Large Eddy Simulation （LES） was performed to investigate the development process of vortices in different sections of a round - shaped hole and a coneshaped hole with 30o under the condition of blowing rate M = 1.0. The results show that the positive and negative vortices in the centreplane and the two wings of the horseshoe vortices in the vertical profiles were shed off new vortices alternately and periodically, the time of shed off of coneshaped hole＇ s is less than the round - shaped hole＇ s at some profile, the acting of jet and cross- flow are more acute in the near wall, so more energy was carried off, then the film cooling effectiveness is enhanced. The counter - rotating vortex played an important effect on the fields of film cooling. The counter - rotating vortex pair （CVP） of the round - shaped hole is bigger than the cone- shaped hole＇ s and the position of the round- shaped hole＇ s vortex center was higher than the coneshaped hole＇ s in the same section. The cooling effectiveness of the round - shaped hole was inferior to the cone-shaped hole＇ s.
出处
《华北电力大学学报（自然科学版）》
CAS
北大核心
2010年第2期79-84,共6页
Journal of North China Electric Power University：Natural Science Edition
基金
国家自然科学基金资助项目(50606005)
关键词
气膜冷却
大涡模拟
流场
反向涡旋对
film cooling
large eddy simulation
flow field
counter - rotating vortex pair
