Numerical Analysis of Located of Angle Sister Holes Effect on the Film Cooling Effectiveness

In current study, three dimensional numerical analysis has been employed to investigate the flow and thermal fields, for different geometry of the hole injection of the film cooling over a flat plate. The computational methodology includes the use of a structured, non-uniform hexahedral grid consisting of the main flow channel, the coolant delivery tube and the feeding plenum, applying the SIMPLE algorithm for pressure-velocity coupling. The two sister holes injection located in the vicinity of to the main injection the cylindrical and the fan-shaped hole by angles of 15, 0 and -15 degree to decrease the strength of counter rotating vortex pairs of the main injection hole and the film cooling performance investigated for two blowing ratios of 0.5 and 1 and density ratio of 1.6. The results show that for blowing ratio of 1, the using of sister holes with the angle of 15 degree with fan-shaped hole injection has the best film cooling performance and increases the performance of film cooling about 37.44% more than the base case which is used from sister holes with the angle of 0 degree with cylindrical hole injection.