Experimental Investigation of Cooling Film Efficiency in the Nozzle Extension of a LOX/H2 Subscale Combustion Chamber

The film cooling is one of the most effective cooling methods used in a combustion chamber. For reliable construction and appropriate dimensioning this cooling method requires a detailed knowledge of the heat transfer processes in real rocket engine like conditions. This paper presents the test specimen and the measurement technique that has been developed und successfully used by the Institute of Space Propulsion for investigations of the aero- thermal behavior of the film cooling in a nozzle extension in a subscale ombustion chamber. The presented nozzle extension has VULCAIN-II like nozzle geometry with a reduction scale of 1:8,3. The film injector simulates the TEG-injection (Turbine Exhaust Gas). Measurement results from investigations performed at the European Research and Technology Test Facility P8 for cryogenic subscale rocket engines are also presented