Circumferential Film Cooling Effectiveness in a LOX/H2 Subscale Combustion Chamber

In order to study wall temperature distribution, film cooling effectiveness and wall heat flux reduction due to film cooling in the circumferential direction, experimental investigations have been carried out, using gaseous hydrogen (GH_2) as a film coolant with tangential slot injection in close proximity to the injector face plate. A Vulcain 2 like test case has been performed, using a combustion chamber pressure up to 11.5 MPa at a high mixture ratio ROF = 6 with ambient temperatures of hydrogen. The experimental investigations have shown significant variations of wall temperatures due to injector design as well as a distribution of film cooling effectiveness which persists far downstream from the film coolant injection slots. Circumferential variations of wall temperature and film cooling effectiveness are much more pronounced at higher combustion chamber pressures.