Systems Analysis on Hypersonic Airplanes using Pre- Cooled Turbojet Engine

Abstract

Systems analysis and evaluation of Mach 5 class hypersonic airplanes is performed. The airplane can fly across the Pacific Ocean in 2 hours. A multi-disciplinary optimization program with aerodynamic, thermal structure, propulsion and trajectory is used to define baseline shape. Pre-cooled turbojet engine is assumed as the propulsion system for the hypersonic airplane. The engine can be operated from takeoff to Mach 5, continuously. This engine has adopted pre-cooling cycle using cryogenic liquid hydrogen. The high temperature inlet air at the hypersonic flight will be cooled by liquid hydrogen for fuel. Surface flow of the airplane at hypersonic speed and low speed are evaluated using results of CFD analyses. The control characteristics with control wings and variation of aerodynamic characteristics by adding strakes are obtained by a low speed wind tunnel experiment. The heat flux distribution on the surface of the airframe at hypersonic cruise condition is evaluated by using the results of CFD analyses. The characteristics of heat shield materials for the surface of the fuselage at downstream of the exhaust gas is evaluated by an elemental experiment.