Heat Balance of a Transpiration-Cooled Ceramic Combustion Chamber

Abstract

HEATS is a lay-out tool for the determination of transient wall heat flux to a transpiration-cooled wall under laminar or turbulent flow conditions. The method is based on heat balances between a flow and a wall material, taking into account aerodynamic heating by the surrounding hot gas, heat conduction within the wall and interior forced convection between transpired coolant and wall. HEATS, in this case, is applied to the transpiration cooling of a ceramic combustion chamber (KSK: Keramische Schubkammer) of the German national research network Propulsion 2010. The LH2 LOX combustion in the chamber reaches temperatures on the order of 3400 K at a pressure of 90 bar. The cooling is performed by supercritical hydrogen at 60 K which is fed through the porous and permeable 10-mm-chamber wall structure made from a carbon fiber/carbon matrix composite. HEATS computation results are compared with experiment results and show good agreement with adeviation of approximately 50K.