Investigation of the Combustion and Ignition Process of a Nitrous Oxide/Ethene Fuel Blend

Kurzfassung

Satellite propulsion systems for orbit- and attitude control mostly operate with Hydrazine as Monopropellant. In respect to the REACH-Regulation there exists a growing demand of propulsion units operating with Green Propellants. Among the different Green Propellants, a very prospective candidate seems to be mixtures of Dinitrogenmonoxide and Carbon Hydrides, also known as Nitric Oxides Fuel Blends. Within the research for alternative space propellants at the German Aerospace Center (DLR) in Lampoldshausen, a special mixture of Dinitrogenmonoxide and Carbon Hydrides was selected and analyzed for further applications in a satellite thruster. The mixture consists of Dinitrogenmonoxide as oxidizer and Ethene as fuel. It is a so called premixed Monopropellant, having the advantages of a Bipropellant (high ISP) as well as the advantages of a Monopropellant in respect to the simple propellant tank and feed system. For the design of a thruster operating with this fuel, the aim of DLRs ongoing research activities in this field is the analysis of the whole combustion process as well as the propellant itself. Several subjects like pressure and mixture influences on the propellant, determination of the characteristic length L*, combustion efficiency, injection and cooling methods will be investigated. For this reason, DLR Lampoldshausen developed and assembled a test bench for N2O/C2H4 propellants. The test setup, the used demonstrator unit and the results of first combustion tests are described in this paper.