General Electric Company

Elmore Verne Sprunger

James Edward Johnson

Arthur P Adamson

John Robert Simmons

William W Thomas

An improved variable cycle turbofan-ramjet engine is disclosed. The engine includes a split fan assembly, a bypass channel surrounding a core engine and a mode selector valve for selectively bypassing air around an aft fan and the core engine. In a first, single bypass mode of operation, the mode selector valve allows air to flow through both a forward fan and the aft fan, and a portion of which bypasses the core engine. In a second, double bypass mode of operation, the mode selector valve allows air from the forward fan to bypass the aft fan and a portion of the air from the forward fan to bypass the core engine. In a third, ramjet mode of operation, the mode selector vane bypasses air around the aft fan and the core engine and the core engine is shut down for ramjet operation. In the preferred embodiment, the forward fan is allowed to windmill and powers a fuel pump connected thereto for providing fuel to a ram burner of the engine for ramjet operation.

Variable cycle turbofan-ramjet engine

A variable cycle turboshaft engine includes a remote fan system and respective high and low pressure systems for selectively driving the fan system in such a manner as to provide VTOL takeoff capability and minimum specific fuel consumption (SFC) at cruise and loiter conditions. For takeoff the fan system is primarily driven by the relatively large low pressure system whose combustor receives the motive fluid from a core bypass duct and, for cruise and loiter conditions, the fan system is driven by both a relativelysmall high pressure core and the low pressure system with its combustor inoperative. A mixer is disposed downstream of the high pressure system for mixing the relatively cold air from the bypass duct and the relatively hot air from the core prior to its flow to the low pressure turbine.

Variable cycle engine

An auxiliary fan is disposed upon the periphery of at least a portion of the fan of a conventional gas turbofan engine. Flow modulating components such as variable vanes and nozzles are utilized in conjunction therewith to produce a wide range of operating bypass ratios. Such an engine is one of the variable cycle variety and has the capability of operating efficiently at both subsonic and supersonic speeds.

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Cincinnati, OH, United States of America

Elmore Verne Sprunger