Turbine blade cooling is a challenging problem for improving the efficiency of a gas turbine. Different macro-channel based cooling strategies, including protective coatings, are generally used to keep the turbine blade temperature within a safe limit. In this work, a minichannel based wall cooling approach is investigated. Minichannel-based cooling has various advantages, including improved cooling uniformity and a lower thermal gradient, bringing the coolant air closer to the exterior wall, resulting in an effective heat transfer.
The mid-span of a turbine blade and the end-wall can be considered flat, after neglecting the small curvature effect. To a certain extent, the flat plate film cooling performance can be used to predict the blade’s mid-span cooling performance. Thus, a conjugate heat transfer investigation on a flat plate with staggered arranged film holes is presented in this work. A minichannel inside the wall structure has been created to enhance the cooling effectiveness of the combined cooling technique. The effect of blowing ratio and three different Biot numbers on overall cooling effectiveness is investigated for various material thermal conductivities. A semi-circular curved body depicting the turbine blade leading edge, with a minichannel placed in the solid wall of the body and three rows of film holes, is also considered in this study.