平板单孔气膜冷却流动特性的实验研究

摘要

In this paper ,an experiment on flow field and flow characteristics of flat‐plat film cooling was conducted using hot‐wire anemometer ,and the air velocity and the turbulence in different section and different blowing rate were obtained .The results show the diversification of speed and turbulence in different section .When blowing ratio is low (M<1) ,cooling gas can form a good size film because its low penetrating power .When blowing ratio is high(M>1) ,the size of kidney‐shaped vortex increases ,which raises the center of vortex and weaken the cooling effect .This work may provide experimental data and the basis for studying the aerodynamic characteristics and the flow characteristics of film cooling .%采用热线风速仪测量系统对平板气膜冷却模型的流场进行实验分析，获得了在不同吹风比下不同截面处的速度与湍流度的变化规律与趋势。结果表明，吹风比较小时（M＜1），冷却气体穿透力弱，能形成较好的冷却气膜；随着吹风比增大（M＞1），在气膜孔下游产生的肾形涡流增大，增高了漩涡中心，且相同位置处的湍流度增大，导致气膜的覆盖面积减小，并使主流与射流换热加剧，减弱了冷却效果。