本文对圆孔和带有侧向扩散出口的侧扩孔气膜冷却进行了大涡模拟计算,对温度场和流场的发展进行了比较和分析。计算结果表明,圆孔形成的成股的冷却射流,与壁面分离明显,使得高温主流被卷席入气膜区域;侧扩孔所形成的冷却气膜没有脱离壁面,并且通过两侧的小股冷却气膜扩宽了横向扩散,可以很好地将高温主流排挤到气膜的两侧,因此可以获得更好的冷却保护效果。
Film cooling induced by both traditionally cylindrical hole and lateral-diffused hole was simulated by Large eddy simulation (LES). The numerical results of temperature distributions and flow fields shown that coolant injected from cylindrical hole detached from wall surface concentrating as a central column, below which hot gas was entrained into cooling zone. Providing wider spreading and better attachment, lateral diffused hole was found to be superior over cylindrical one.