Internal and Film Cooling of a Flat Plate With Conjugate Heat Transfer

Abstract

Computations were performed to study the internal and film cooling of a flat plate with and without thermal-barrier coating (TBC) that account for the heat transfer in the gas and in the solid. The goal is to understand the effects of the conjugate heat transfer on the temperature distribution in the region about the film-cooling hole and in the region further downstream of a row of film-cooling holes. Results obtained show that when there are no TBC, conduction heat transfer in the plate smears out the adverse effects of hot-gas entrainment by the film-cooling jet. When there is a TBC, the surface temperature and the temperature in the super alloy are greatly reduced because of the low thermal conductivity of the ceramic top coat (CTC), but the temperature gradient, which is nearly aligned with the X-axis further away from the film-cooling hole, turns towards the side of the flat plate with internal cooling, which alters the thermal stress distribution. Reducing the thermal conductivity of the CTC by a factor of 10 was found to increase slightly instead of decrease the surface temperature. This computational study is based on the ensemble average continuity, Navier-Stokes, and energy equations closed by the ideal gas equation of state and the two-equation realizeable k-ε turbulence model for the gas phase and the Fourier equations for conduction in the solid phase.