Japan Aerospace Exploration Agency Space Transportation Propulsion Research and Development Center, Office of Space Flight and Operations
Japan Aerospace Exploration Agency Space Transportation Propulsion Research and Development Center, Office of Space Flight and Operations
Japan Aerospace Exploration Agency Space Transportation Propulsion Research and Development Center, Office of Space Flight and Operations
Japan Aerospace Exploration Agency Space Transportation Propulsion Research and Development Center, Office of Space Flight and Operations
Japan Aerospace Exploration Agency Space Transportation Propulsion Research and Development Center, Office of Space Flight and Operations
A combustor model of a rocket-ramjet combined-cycle engine was tested in the ejector-jet mode under a sea-level, static condition. The model had two rockets in the duct. Propellants were gaseous hydrogen and oxygen. Design factors of the combustor were cross sections at the entrance and the exit, length of the combustor, fuel injection position and rocket operating conditions. In the tests, the designed operation of the ejector-jet was successfully attained, that is, breathed air was choked at the throat section. Supersonic rocket exhaust and air were decelerated in the divergent duct with an increase of the wall pressure. Combustion gas choked at the exit. The mean combustion efficiency was 0.8 according to pitot pressure measurement and gas sampling. Suction performance was increased with an increase of the mixture ratio of the rockets. Pressure level in the model was affected by the length of the upstream straight section. The combustion status was not affected by the length of the downstream straight section or the position of fuel injection. An increase of fuel caused an increase of the pressure.