双扇形孔气膜冷却效率的研究

对平板表面的双扇形孔排气膜冷却特性进行了研究,包括孔节距、动量比和主流湍流度对气膜冷却效率的影响.气膜孔的直径为d,气膜孔与主流方向的夹角为45°孔节距有2d,3d和4d,动量比有1,2和4,主流湍流度有0.4%和8%.结果表明.气膜冷却效率随孔节距增大而降低;孔节距为2d时,动量比增大会引起气膜冷却效率显著增加;孔节距为4d时,气膜冷却效率受动量比的影响相对较小;在孔节距及动量比均较大时,主流湍流度的增大会导致气膜冷却效率较为明显的下降.

Investigation of film cooling effectiveness for double fan-shaped holes

This paper presents detail measurements of film cooling effectiveness in a flat plan for a row double fan-shaped holes.The streamwise angle of hole was 45°and the diameter of hole was d.The pitch-to-diameter ratio(p/d) contained 2,3 and 4.The momentum flux ratios varied from 1 to 4 and the turbulence level contained 0.4% and 8%.The result indicated that the double fan-shaped holes made significant improvement of film cooling effectiveness compared with the round holes.The variety of the p/d had great effects on film cooling effectiveness.Increasing the momentum flux ratio lead to large improvement of film cooling effectiveness at the p/d=2,while the momentum flux ratio had small effects on it at the p/d=4.The enhancement of turbulence level lead to obvious decrease in film cooling effectiveness when p/d is large and the momentum ratio is high.