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以加力燃烧室纵向波纹隔热屏为研究对象,采用数值方法,对不同吹风比、不同展向间距以及不同流向间距的纵向波纹隔热屏进行计算,获得了纵向波纹隔热屏流场流动特征和气膜冷却效率的变化。结果表明:纵向波纹隔热屏气膜冷却与常规的平板气膜冷却有着本质的区别,表现出气膜射流脱离壁面、较小吹风比下的冷却效率受结构影响大等特征;较低吹风比(M<1.3)下气膜冷却效率沿着流向呈现出起伏变化,较高吹风比(M≥1.3)下的气膜冷却效率沿程逐渐增加,最终趋于平缓;对于几何结构,吹风比约为2.5时效率达到最大值;随着展向间距的减小,气膜冷却效率逐渐增加,但增加较为缓慢;气膜冷却效率并不是一直随流向间距的减小而增加,当流向间距从4.2倍孔径减小到3.25倍孔径时,在第二周期波峰区域,冷却效率反而降低,随着流向间距进一步减小,局部冷却效率降低的区域甚至扩大,并占据了波纹隔热屏的第二个波峰。
Taking the longitudinal corrugated heat insulation panel of afterburner as the research object, the longitudinal corrugated heat insulation screen with different blowing ratio, different span and different spacing is calculated by numerical method, and the flow field of longitudinal corrugated heat insulation screen is obtained Features and changes in film cooling efficiency. The results show that there is an essential difference between the film cooling of the longitudinal corrugated heat shield and the conventional flat film cooling, which shows that the jet of the gas film is detached from the wall surface and the cooling efficiency is affected greatly by the structure under the small blow ratio. <1.3), the film cooling efficiency showed a fluctuation along the flow direction. The cooling efficiency of the film gradually increased along with the higher blowing ratio (M≥1.3), and eventually became gentle. For the geometric structure, the blowing ratio was about 2.5 The efficiency of the film cooling gradually increased, but increased more slowly; the cooling efficiency of the film did not always increase with the decrease of the flow spacing. When the flow spacing was from 4.2 times the aperture When the aperture is reduced to 3.25 times, the cooling efficiency will decrease in the second peak area. As the flow distance decreases further, the area with reduced local cooling efficiency will even expand and occupy the second peak of the corrugated heat shield.