Abstract
The Institute of Space and Astronautical Science (ISAS) has been engaged in the development study on the Air Turbo Ramjet (ATR) engine since 1986 in cooperation with the Ishikawajima Harima Heavy Industries Co., Ltd.(IHI) The ATR is one of the most preferable candidate for the propulsion system of a future space plane. ATR is the combined cycle engine performing like a turbojet engine at subsonic flight and a fan-boosted ramjet at supersonic and hypersonic flight below Mach 6. The advantage feature of ATR engine is that the turbine inlet temperature is decoupled from the incoming air temperature which increases as the flight Mach number increases, thus ATR cycle does not reduce thrust capability due to the turbine material limits on the hypersonic flight. Our ATR engine system was named “ATREX” after employing the expander cycle. The ATREX is energized by thermal energy extracted regeneratively in both the precooler installed in air intake and the heat exchanger in combustion chamber. The ATREX works in the flight condition from sea level static up to Mach 6 at 35 km altitude. The ATREX employs the tip turbine configuration for compactness of turbo machinery. We have tested the ATREX system at the sea level static condition using the 1/4-scale model (ATREX-500) with fan inlet diameter of 300 mm and overall length of 2,200 mm. The present paper addresses the analysis of the Air-Turbo Ramjet (ATR) Engine to be applied for the TSTO Space Plane and the test results of the ATREX engine at sea level static condition.
