关键词: 气膜冷却;旋转;大涡模拟;湍流结构;来流条件

Abstract: Large eddy simulation was performed to investigate the influence of inflow condition on the film cooling over flat plate has 30° streamwise inclined hole.The Reynolds number at the jet exit was 2 600,and the blowing ratio was 0.5.The flow and heat transfer without rotation and with streamwise rotating number 0.02 were calculated,and the effect of rotation on film cooling under different inflow conditions was compared.Numerical results showed that the most significant influence of rotation on film cooling was the asymmetric distributions of turbulence structure and spanwise deviation of the film when the inflow was uniform.As the inflow became fully developed,rotation induced turbulence structures in the boundary layer of inflow.The resultant near wall streak submerged hairpin structure and induced more intensively diffusion of the jet.Thus the coverage of the film was enlarged and the peak of film cooling effectiveness was reduced.Such comparison showed that the indirect influence of rotation on film cooling by changing the flow structures in the boundary layer of inflow was more significant than the direct rotational effect.

Key words: Film cooling;Rotation;Large eddy simulation;Turbulence structure;Inflow condition