Research on high pressure cryogenic combustion

Due to their high specific impulse, Oxygen/Hydrogen systems are often used to increase launcher performance and will probably continue to be the preferred option for the next decades. In order to get insight into complex processes involved in the combustion of such propellants, research efforts have been conducted in both France and Germany including theoretical and experimental activities. This article deals with recent progress achieved by research teams from both countries in high pressure Oxygen/Hydrogen (O2/H2) combustion systems. In France, the research program was conducted in the framework of the GDR group including Snecma Moteurs-Rocket Engine Division, Centre National dʹÉtudes Spatiales (CNES), Centre National de la Recherche Scientifique (CNRS) and ONERA. In Germany, research was conducted in the framework of the national technology program “TEKAN” involving universities, DLR and Astrium. A close cooperation between teams was made possible through a Memorandum of Understanding (MoU) on research on high pressure cryogenic combustion. general design issues of liquid propellant engines are addressed, demonstrating a clear need for a new approach in engine development taking into account the complex chemical and physical processes in rocket engines. A brief description about the organization of the research programs is followed by a short presentation of the test facilities and the experimental setupʹs in use. Examples of experimental as well as numerical achievements applying sophisticated optical diagnostic tools are discussed and finally, the paper summarises the results achieved so far and addresses the questions still open.