The feasibility of sustained hypersonic flight within the earth's atmosphere is examined, utilizing the "coolant-fuel" system as an Aero-Thermodynamic Propulsion (ATP) Method to eliminate excessive aerodynamic frictional heating and to increase propulsive efficiency. Such systems are of current interest for all flight plans in which high speed is the prime requirement, and also for some classes of flight of prescribed range which are handicapped toy insufficient unit energy content of conventional fuels (this includes, as a particular case, the problem of extreme long range manned flight). Coolant-fuels are considered from the dual standpoint of the propellant and of the missile aerodynamics. The propellant study con?templates the ability of fuels to absorb heat and the impulse gains achieved thereby. The missile study outlines a method for estimation of aerodynamic friction heating and the extent of heat transfer to the coolant-fuel as functions of the missile speed, configuration, flight plan, and state of the boundary layer. It is found that cooling which reduces equilibrium tempera?tures to within manageable limits can also be made to increase the energy content of suitably selected coolant-fuels by as much as 50 per cent, leading to most substantial incidental benefits to the propulsive system.
展开▼
