发散孔纵向波纹隔热屏气膜冷却特性研究

Numerical simulation on air film cooling characters of the longitudinal ripple heat shield with effusion holes

对燃烧室内开有发散孔的纵向波纹隔热屏进行了数值模拟。研究隔热屏的四种结构参数开孔率、波纹板高度、气膜孔直径和冷却通道高度的改变对隔热屏冷却效果的影响。研究表明:在气膜孔出流总量相同的情况下,3%开孔率比6%开孔率的隔热屏平均冷却效率较高;汉纹板高度对隔热屏冷却效果影响较大,波纹板无量纲高度B=1%时的隔热屏平均冷却效率最高;冷却通道高度和气膜孔直径对隔热屏冷却效果影响较小,冷却通道高度只影响隔热屏前段的冷却效率,发散孔气膜孔直径的大小则对隔热屏冷却效率几乎没有影响。

This paper presents numerical simulation of effusion holes on the longitudinal wavy liner in the eombustor. The investigation focused on the parameters affecting cooling effectiveness, which are opening ratio, height of ripple board, diameter of cooling holes and height of cooling passage. The results have showed that the heat shield gets a higher average cooling effectiveness when the opening ratio a = 3 % compared with a = 6 %, on the condition of the same total flow effusing from holes. Cooling efficiency is sensitive to the height of ripple board, the heat shield gets the highest cooling effectiveness when the dimensionless height of ripple board B = 1% compared with B = 2 % and B = 3.33 %. Chang- ing the height of cooling passage and the diameter of cooling holes have a little influence on the cooling effectiveness. Changing the height of cooling passage only influences the front of the wavy liner, and the size of the diameter nearly docsn＇ t influence the cooling efficiency of the liner.