Design Study on a Small Pre-Cooled Turbojet Engine for Flight Experiments

Abstract

Design aspects of a small pre-cooled turbojet engine for flight experiments are investigated in this study. Pre-cooled turbojet engine is a hypersonic engine suitable for Two Stage To Orbit (TSTO) Space Planes and other hypersonic cruise vehicles. The engine has a capability to accelerate vehicles with a flight speed range between Mach 0 and 6. The payload injection capability of the vehicle appeared to be higher than that with rocket engines, in the former analysis. Some component models for the engine have been tested under simulated conditions. Aerodynamic performances of a variable air intake have been investigated by wind tunnel tests. Anti-frosting technology has been established by using a light weight pre-cooler. System performance of pre-cooling cycle under sea level static condition has been obtained. High temperature structure for a ram combustor and a variable exhaust nozzle has been examined by firing tests. A small pre-cooled turbojet engine for flight experiments is designed based on the component models. The engine will be used for the experiments to obtain thermo-dynamic data of the pre-cooled cycle with the designed flight speed range. Results of thermo-dynamic analyses, CFD analyses and component tests are described in this study. Those results are used to determine the final scale and shape of each component.