Film Cooling from Two Rows of Holes with Opposite Orientation Angles : Heat Transfer

Heat transfer coefficient ratio distributions are measured for film cooling from two rows of holes with opposite orientation angles. The inclination angle is fixed at 35゜, and orientation angles are set to 45゜ for the downstream row and -45゜ for the upsteam row. Four film cooling hole arrangements including inline and staggered configurations are investigated. The blowing ratios considered are 0.5, 1.0 and Configuration effects on the heat transfer are not significant at the blowing ratio of 0.5. At the higher blowing ratios of 1.0 and 2.0, however, the inline configuration produces higher heat transfer coefficient distributions compared to others. In spite of the high heat transfer level, the inline configuration shows better film cooling performance, represented by the heat flux ratio, at the blowing rations of 1.0 and 2.0 due to its higher adiabatic film cooling effectiveness.