A conservation-based discretization approach for conjugate heat transfer calculations in hot-gas ducting turbomachinery components

A numerical procedure has been developed for simulation of conjugate heat transfer in generalized coordinates and used in some typical turbomachinery applications. Discretized equations for nodes located exactly on the solid–fluid interface were derived using energy conservation principles, yielding the corresponding temperatures directly, without the need for inter- or extrapolation from adjacent nodes. A finite-volume-based computer code was used along with the SIMPLE algorithm and the k–ϵ turbulence model. The turbulent flow and heat transfer in a stepped labyrinth seal and in an effusion-cooled combustor liner have been studied and results were compared with measured data showing good agreement. In the labyrinth-seal case, the comparisons were in terms of surface temperatures and Nusselt numbers, while for the effusion-cooling case in terms of the streamwise velocity and the film-cooling effectiveness for different blowing and density ratios. In the latter case, two different liner materials were used to study the influence of the thermal conductivity on film-cooling characteristics and the agreement was better for the lowest of the two conductivities. The dominant flow structures could be captured with good accuracy.