复合角对曲壁多斜孔冷却特性的影响

Influence of Compound Angle on Effusion Cooling Effectiveness Through Inclined Holes in Curved Wall

在燃烧室曲壁中,采用复合角分别为0°、30°和65°的多斜孔冷却结构,数值模拟和实验研究了吹风比为3.5时的流场和气膜冷却效率的分布规律。结果表明:相比无复合角模型,引入复合角后,气膜出流的展向扩散增强,气膜在相邻列之间搭接较好,冷却效率提高,同时气膜高度方向扩散减弱,减少了与高温主流的掺混,使气膜覆盖长度增加;当复合角从30°增大为65°时,冷却效率略有提升,流量系数随复合角的增大先增大后减小。

Numerical simulation and experimental research were conducted to investigate the distribution of flow field and film cooling effectiveness at a blowing ratio of 3.5 in the combustion chamber under the condition of curved wall,in which the compound angle of multi-inclined holes is 0°,30°and 65°.Results show that compared with the model of 0°,the introduction of compound angle enhances the spanwise diffusion of cooling air flow,and the film has better overlapping effect between two adjacent rows of holes,resulting in increased cooling efficiency,weakened diffusion in height direction,declined involvement with high-temperature gas,and increased length of film coverage.When the compound angel is increased from 30°to65°,the cooling efficiency improves slightly,while the discharge coefficient shows a tendency to increase first and then decrease with the rise of compound angle.