Fuel gas generator for airbreathing propulsion systems

摘要

A gas generator propellant formulation suitable for use in an air turbo rocket (ATR) which employs an air breathing system that uses fuel gases produced by a gas generator propellant to operate the engine's turbine is provided which can also be used with other airbreathing propulsion systems that require a high gravimetric heating value (GHV). The basic fuel gas generator propellant formulation comprises in weight percent a tetraalkylammonium borohydride 50-100; lithium nitrate 0-50; and optional additives of hydroxy proply cellulose 0-20 and silica or silicon 0-20. The basic fuel gas propellant formulation can also employ an encapsulated tetraalkylammonium borohydride which employs an encapsulation polymer selected from the group consisting of polyethylene, polypropylene, and ethyl cellulose. When employing an encapsulated tetraalkylammonium borohydride a binder is employed selected from the group consisting of polybutadiene and polyether cured with 0.50% selected from hexamethylene diisocyanate and isophorene diisocyanate. The encapsulated fuel gas generator propellant formulation comprises an encapsulated tetraalkylammonium borohydride 50%; binder 0-45%; and lithium nitrate 5%. Lithium nitrate in the fuel gas generator propellant formulation enables the composition to be ignited with a hot wire. The tetraalkylammonium borohydride is selected from the group of tetraalkylammonium borohydrides consisting of tetramethylammonium borohydride, tetraethylammonium borohydride tetrapropylammonium borohydride, and tetrabutylammonium borohydride.