Rapid thermal analysis method for film cooling coupled with thermal barrier coatings

In order to efficiently design and analyze the turbine blade cooling structures, a rapid thermal analysis method for film cooling coupled with thermal barrier coatings (TBC) was established and basically verified. Based on the morphologies of the conductive heat flow streamlines in the metal region, the heat transfer processes were separated into three parts of mutual adiabatic, so as to reduce the difficulties of equation construction. Topologically transforming methods were applied, thus the complicated 3D heat transfer processes were translated into 1D ones like flat plates or fan-shaped segments with uniform wall thickness. A set of 40 direct calculation formulas were derived accordingly, which achieves a rapid solution of the weighted average temperature at the objective walls. Many effects on the wall temperature could be analyzed by this method, such as the flow and heat transfer conditions, the geometries of both film cooling hole and TBC, and also the material properties of them. The accuracy of the method was investigated by comparing its results with the fiducial ones obtained from 3D simulations. The relative error (δ) of these wall temperatures were within ±1.25% considering various TBC coverage schemes and blowing ratios (M) operating conditions, which met the requirements of engineering applications.