3-D Numerical Analysis of Curved Transpiration Cooled Plates and Homogenization of Their Aerothermal Properties

Three different designs of a transpiration cooled multilayer plate — plane, convex and concave — are analysed numerically by application of a 3-D conjugate fluid flow and heat transfer solver. The geometrical setup and the fluid flow conditions are derived from modern gas turbine components. The conjugate analysis of these designs focus on the influence of the surface curvature, the cooling film development on the plate surface, the fluid structure in the cooling channels and on the cooling efficiency of the plate. Moreover, to predict the effective thermal properties and the permeability of these multilayer plates, a multiscale approach based on the homogenization technique is employed. This method allows the calculation of effective equivalent properties either for each layer or for the multilayer of superalloy, bondcoat and thermal barrier coating (TBC). Permeabilities of the different designs are presented in detail for the TBC layer. The influence of the plate curvature and the blowing ratio on the effective orthotropic thermal conductivities is finally outlined.