Material Selection and Structural Integration of Actively Cooled High Speed Combustion Chamber

Abstract

Thermal management in the supersonic combustion chambers subjected to high heat fluxes is vital for maintaining their integrity. At high temperatures ordinary materials cannot sustain the high heat loads. On the other hand, the prevailing high temperature gradients, necessitates the provision for expansion to avoid build of thermal stresses for the integration. Hence, thermal management needs a holistic approach encompassing the areas of material selection, heat transfer and structural integration. The current state of art research is focused on achieving this by active cooling through endothermic fuel, which is used as a coolant due to the advantages such as reduced weight and improved heat sink capacities. Particularly the space applications pose serious limitations on the weight. 1D thermo-structural hand calculations can be easy point to start with to arrive at the optimized shape of the single actively cooled channel. But the underlying assumptions and owing to the 1D nature of the such calculations, pose limitation towards understanding the behavior of the active panel as a whole and achieving the practical integration strategy. Therefore, there is need to perform 3D CFD and FEA thermo-structural analysis of the active panel structure. This paper extends upon the approach of 1D analytical material selection methodology through weight optimization followed by rigorous CFD and FEA analysis to understand and device ways for structural integration for long duration flight of about 600 seconds.