An Investigation of the Heat Transfer for Full Coverage Film Cooling

Abstract

An experimental study was conducted on the heat transfer to a film-cooled flat plate with a full coverage array of normal holes. The film cooling array consisted of ten staggered coolant rows, and each coolant hole had an L/D = 1.0 and an injection angle of α = 90°. Measurements of the heat transfer coefficient with and without film cooling were taken, in order to determine the increase in the heat transfer coefficient due to coolant injection. These experiments were conducted with heated and unheated starting lengths, and with low and high mainstream turbulence levels. The heat transfer coefficient ratios were used in conjunction with adiabatic effectiveness data taken in a previous study to determine the distributions of the overall heat load reduction. Heat transfer coefficient data from a single row of coolant holes were also taken. These data were used to evaluate several concepts for predicting full coverage heat transfer coefficient distributions based on the single row data.