The Space Hypergolic Bipropellant Internal Combustion Engine

This paper describes two unconventional types of internal combustion reciprocating engines designed to drive rectified alternators to provide electrical power for space missions. The engines use Aerozine 50 as the fuel and nitrogen tetroxide as the oxidizer. These two propellants are commonly used in liquid rockets and are characterized by the combination of high energy release and immediate ignition upon contact. The first engine is designed to provide 6 hp using a plunger type propellant injection system and in-head exhaust valve. The second provides 4.5 hp using a unique pressure fed, cam-operated, poppet injector and cylinder exhaust ports. One of the critical problems in the design of these engines concerns the very short time interval during which the propellants must be injected and burned.