Abstract

Traditional metallic components in gas turbine engine hot gas paths are starting to be replaced by ceramic matrix composite (CMC) parts. These parts can be cooled using both internal and external cooling, such as film cooling. The overall cooling effectiveness is determined not only by the design of coolant flow, but also by the conduction through the materiel itself. A complication of CMC components is their anisotropic thermal conductivity, which changes the flow of heat through a part compared to a traditional metallic component. The result is a different overall effectiveness than would be obtained with an isotropic model of the part, even if such a model had the same average thermal conductivity and an identical cooling geometry.  This adds complication to modeling efforts aimed at predicting thermal behavior of the high temperature CMC engine components.

Computational fluid dynamics (CFD) simulations were performed in order to isolate the effect anisotropic thermal conductivity has on a cooling architecture. The model incorporated both internal and external cooling. The effect of cooling on each surface was also isolated to determine the effect of directional conduction on overall effectiveness. Results show the specific locations and unique effect of anisotropic thermal conduction on overall effectiveness.