DEVELOPMENT STUDY ON THE AIR TURBO-RAMJET FOR FUTURE SPACE PLANES

The present paper addresses the development study of an Air Turbo-Ramjet (ATR) engine conducted at the Institute of Space and Astronautical Sciences (ISAS) in cooperation with Ishikawajima-Harima Heavy Industries Co., Ltd (IHI). Many kinds of air-breathing propulsion systems have been proposed for a space transportation system. Of which the ATR has the superior capability in specific impulse with effective thrust over the sea level static to hypersonic flight condition of up to Mach 6. Thus, ATR is one of the preferable candidates as an air-breathing propulsion system for future space planes. We had reported the analytical study on the various derivatives of ATR engine cycle previously. The ISAS made the long-range research plan on the ATR engine, which is implemented by three verification steps (1) sea level static test, (2) hypersonic simulation test with wind tunnel and (3) actual flight test with a flying test bed. In this paper we present the system design of the expander cycle ATR engine, named ATREX, the scenario of development study and the ATREX engine configuration for the sea level static test presently in progress. The ATREX engine proposed by ISAS and IHI is characterized by the hydrogen fueled expander cycle with a pre-cooler air intake and a heat exchanger in the combustion chamber and the tip turbine configuration.