多孔纵向波纹表面气膜冷却效率实验研究

实验研究了开孔方式、主流雷诺数及平均吹风比等因素对某种多孔纵向波纹表面沿程气膜冷却效率的影响规律.实验参数变化范围:基于波长的主流雷诺数120000～250000,平均吹风比0.2～2.0.研究结果表明:平均吹风比是影响波纹结构沿程气膜冷却效率的主要因素,在较大的吹风比范围内各方案沿程气膜冷却效率呈波纹状变化趋势;从提高气膜冷却效率角度考虑,平均吹风比小于0.6时.波峰及波峰附近开孔方案较优,波谷及波谷下游附近开孔方案较差.

Experimental investigation on film cooling effectiveness of multi-hole at longitudinal wavy surface

This paper describes experimental studies on film cooling effectiveness of a corrugated wall involving multi-holes for the sake of cooling air injection. The influences of the arrangements of film cooling holes, average blowing ratio and main flow Reynolds number on the film cooling effectiveness were studied. Four types of hole arrangements were investigated at four Reynolds numbers of the main flow, ranging from 1.2×105 to 2.5×105, and average blowing ratios, ranging from 0.2 to 2.0. The results indicate that the average blowing ratio is the main factor which contributes to film cooling effectiveness, and the film cooling effectiveness varies with the shape of the wall among a large range of average blowing ratio. The rows of hole on the valley and in the downstream region near the valley can decrease film cooling effectiveness. In contrast to it , the rows of hole on the crest and in the vicinal region of the crest can get better value.