Development study on the atrex engine

The development study project on the ATREX engine is now under way in the Institute of Space and Astronautical Science (ISAS) along the development approach shown in Fig. 1. This project is proceeding in cooperation with Ishikawajima Harima Heavy Industries on the engine, with Kawasaki Heavy Industries on the air intake including the precooler, with Mitsubishi Heavy Industries on the flying test bed including the takeoff assist system and Sumitomo Heavy Industries on the test facilities. ATREX is the combined cycle ATR (Air TurboRamjet) engine performing like a turbojet engine at subsonic flight and a fan-boosted ramjet as supersonic and hypersonic flight. ATREX works in an expander cycle using liquid hydrogen as a fuel. ATREX is energized by thermal energy extracted regeneratively in both the precooler installed in the air intake and the heat exchanger in the combustion chamber. ATREX is available to produce the effective thrust in the flight condition from sea-level static up to Mach 6 at 35 km altitude. ATREX employs the tip turbine configuration which allows the compactness and the light weight of turbo machinery. The ATREX engine will be applied for the propulsion system of the fly-back booster of the TSTO space plane. Up to now, the 1/4-scale model (ATREX-500) has been tested at sea-level static condition. The fundamental study on the air intakes coupling with the precooler and the variable geometry air intake has been done using the wind tunnel. We have also studied on the application of advanced carbon-carbon composite for the turbo-machinery of the ATREX. The flight test of ATREX is now planning. In the present paper, after briefing on the ATREX engine system the wind tunnel tests on ATREX air-intakes and precoolers, the development study on ATREX turbo machinery made of advanced carbon-carbon composite material are mentioned and finally the planning on the flight test of the ATREX engine is presented.