Optimized inlet geometry of a laidback fan-shaped film cooling hole - Experimental study of film cooling performance

Results show that the cooling hole inlet geometry tremendously affects cooling performance. Diffuser aerodynamics are altered for all investigated geometries with a modified inlet. This leads to a more symmetrical pattern of the film cooling jet for two of the investigated geometries. As a consequence, film cooling effectiveness is increased compared to the baseline case. The disadvantages of a perpendicular coolant flow in terms of effectiveness are entirely eliminated. Additionally, heat transfer coefficients are lowered. An overall evaluation reveals that the heat flux into the wall is significantly reduced for the proposed optimized cooling hole geometries.