Film-cooling performance and heat transfer over an inclined film-cooled surface

Experiments have been performed to study and obtain the adiabatic wall film-cooling effectiveness and the heat transfer over a film-cooled surface that is made inclined at various angles with respect to a uniform How. The vertical temperature distribution was measured to infer the flow structure and the rate of mixing of the film jet with the freestream. The inclination angle of the film-cooled surface ranges from -20 to 20 deg with an increment of 5 deg, the blowing parameter from 0.5 to 2.0 (0.5,0.7, 1.0,1.5,2.0). It is found that the mixing of the film jet with the freestream is significantly affected by the inclination angle of the film-cooled surface. The divergence of the film-cooled surface can make the How unstable and cause flow separation, whereas the convergence has both stabilization and impingement effects on the film jet. This has a very complicated effect on both the film-cooling performance and the heat transfer under the film. More detailed discussion on the How and the heat transfer is presented. Correlations for both the film cooling effectiveness and the heat transfer under the film are provided.