气膜冷却对叶栅端壁二次流的影响

通过对两种叶栅流道端壁气膜冷却的数值模拟,分析比较了流道内部的损失和气流落后角等气动参数,得到了以下几个结论：端壁气膜冷却对于叶栅端壁静压分布影响不大,几乎没有改变端壁横向压力梯度.吹风比m=1时的端壁气膜冷却对于反动式叶栅影响较大,有效抑制反动式叶栅的二次流发展.而对冲动式叶栅,端壁气膜冷却影响并不明显.冲动式叶栅出口端壁附近出现了一个低温的反向涡流,这个涡流的形成与端壁气膜冷却喷射、角涡、叶栅中部吸力面壁面分离密切相关.

Effect of Gas Film Cooling to Secondary Flow of End Wall of Grid

Abstact：Through the numerical simulation for the gas film cooling on the end wall in two types of cascade flowing pass,the parameters of aerodynamic loss in the pass and lag angle of air flow were analyzed and compared.The followings were concluded：the process of film cooling on end wall has a little effect to the distribution of static pressure on the end wall and there is almost no lateral pressure gradient existed; when inlet blowing ratio equals to 1,the process of film cooling on end wall has comparatively great effect to inverse cascade,and it can effectively inhibit the development of secondary flow in inverse cascade; to impulse cascade there is also no obvious effect resulted from film cooling on end wall because there creates a low temperature reversed vortex near the outlet of impulse cascade,and the forming of this vortex is closely related to the gas film cooling and comer vortex on end wall and the separation of suction section from wall.