Investigation of Transpiration Cooling Performance in Lox/Methane Liquid Rocket Engines

Abstract

A transpiration cooling model using high-pressure, real gas properties has been developed in order to determine methane transpiration cooling performance in the throat region of a highthrust, high-pressure LOX/LCH 4 liquid rocket engine (LRE), such as those being currently investigated in European Union (EU). The model is a series of non linear ordinary differential equations one-dimensional for the conduction-convection of heat between the coolant and the porous material and neglects for simplicity vapour formation. This last assumption occurs, in fact, only with low thermal conductivity materials (k wall = 20 W/mK) and at low coolant injection temperature (T cool_in = 140 K), these conditions being present only in 3 of the 21 cases examined in the parametric analysis. Only steady-state results are presented; comparisons were not made to test data as experiments to this purpose are still in the planning process. Temperature profiles along the liner wall have been numerically obtained by varying liner porosity (ε = 15% ÷17%), conductivity (k wall = 20 W/mK and 100 W/mK) and coolant