Construction has begun of a flight-ready variable inlet pre-cooled turbojet engine that could power a Japanese two-stage to orbit launcher or an aircraft that would travel from Tokyo to Los Angeles in 2h.
The variable inlet is used to cope with the changing incoming air pressures over the Mach range and a heat exchanger, filled with hydrogen, absorbs the incoming air's heat to keep the engine cool. A prototype engine has been ground tested in conditions from zero to M6. Now a lightweight version of the engine is being built to be flight ready in two years, when a test flight will take place.
The engine will be carried to a high altitude by a balloon and incorporated into a missile-like vehicle. During the freefall flight the vehicle will reach M2.
A second flight will use a solid-rocket booster to increase that speed. "We have introduced technology to reduce the forces acting upon the variable inlet. Hydrogen will flow through the internal volume of the inlet flap to cool it," said Hideyuki Taguchi, a senior researcher at the Japan Aerospace Exploration Agency's Future Space Transportation Research Center, speaking at last week's American Insititute of Aeronautics and Astronautics/CIRA 13th International Space Planes and Hypersonics Systems and Technologies Conference at Capua, near Naples in Italy.
A part of JAXA's high-speed transport project, the vehicle integration and flight test programme will cost $2 million. The agency is working with IHI Aerospace, which is based near Tokyo.
ROB COPPINGER/NAPLES
Source: Flight International
