一种计算气膜冷却效率的新模型

New model to calculate the film cooling effectiveness

关键词:  薄膜冷却  喷射混合流  冷却叶片  喷出率  掺混模型  等效边界层

Key words:  Film cooling  Jet mixing flow  Cooled blade  Jet out ratio  Mixing model  Equivalent boundary layer

摘要:

提出了等效边界层的概念及“质量喷出率”的参数 ,并在此基础上提出了一种新的离散孔气膜冷却的掺混模型 ,解决了冷气喷出后边界层内速度分布波动大及高吹风比时冷气穿透边界层引起的计算困难。计算表明 ,与以往气膜冷却的掺混模型相比 ,新的掺混模型能适用于较高吹风比情况下的冷却效率的计算问题

Abstract:

A new mixing model for the discrete hole injection process discription was suggested with the conception of equivalence boundary layer and parameters of jet out ratio. This injection model was incorporated in a two dimensional boundary layer code using the low Reynolds number k ε two equation turbulent model. The computation was carried out smoothly with the use of equivalence boundary layer. The conception of jet out ratio was used to account for the effect of cooling air penetrated through boundary layer. The calculation results show that the new model could be used to compute the film cooling effectiveness of discrete hole injection process with higher blowing ratios.