Experimental Investigation of Film Cooling with Tangential Slot Injection in a LOX/CH4 Subscale Rocket Combustion Chamber

Abstract

Within the frame of a broader activity towards research into the application of methane in cryogenic liquid rocket engines, the efficiency of film cooling was studied in a LOX/CH 4 fired subscale sized model combustor. Aiming at booster as well as upper stage applications, the combustion pressure levels have been varied between 4 MPa and 7 MPa. The effectiveness of the ambient temperature film was determined in axial and circumferential directions by measuring temperature gradients in the copper liner material. The experiments revealed remarkable circumferential differences of the film cooling efficiency which remain existent far downstream. However, circumferential film cooling varieties are more pronounced at close proximity of the point of film coolant injection.