横向间距与密度比对双射流气膜冷却特性影响

使用压力敏感漆（PSP)测量技术对平板上的双射流气膜冷却结构进行了研究。双射流孔间横向距离分别为0、0.5、1.0;孔间流向距离保持为3.0。密度比分别为1.0、1.5、2.5,吹风比分别为0.5、1.0、1.5、2.0。研究了孔间横向距离与密度比对双射流气膜冷却效率的影响。结果表明:双射流孔间横向距离为0时,气膜横向覆盖受限;随横向距离增大,气膜覆盖范围增加;但在横向距离过大时,气膜覆盖变差。随密度比增加,射流吹离减弱,气膜冷却效率提高。在高密度比下,横向距离较大的双射流孔气膜冷却效率较高。 

Effects of spanwise distance and density ratio on the characteristic of double-jet film-cooling

Double-jet film-cooling geometries on a flat plate were investigated using pressure sensitive paint (PSP) measurement technique. The spanwise distance between the double-jet film-cooling holes varied as 0, 0.5 and 1.0, while the streamwise distance was kept as 3.0. The density ratio was 1.0, 1.5 and 2.5, while the blowing ratio was 0.5, 1.0, 1.5 and 2.0. The effects of spanwise distance and density ratio on the effectiveness of double-jet film-cooling holes were studied. The results showed, at spanwise distance of 0, the lateral coverage of the film was suppressed. As the spanwise distance increased, the film covered more areas. However, while the spanwise distance was too large, the film coverage degraded. With the increase of density ratio, the lifting-off of the jets weakened, and the film-cooling effectiveness improved. At high density ratios, higher film-cooling effectiveness was achieved by the double-jet film-cooling holes with larger spanwise distance.