Gm Global Technolgoy Operations, Inc.

Robert H Aspinwall

Charles R Baker

A gas turbine engine has an inlet compressor with a stepped centrifugal impeller and a double diffuser therefrom controlled by valve means and operative to supply air to combustion apparatus from when motive fluid is directed through a turbine to drive the compressor. The turbine may drive the load or a second power turbine in series with the compressor drive turbine can be included. The discharge from the double diffuser is controlled to vary the mass flow of the engine for operation at idling and under light loads and operable to be completely open for higher power output of the engine.

Gas turbine engine with stepped inlet compressor

A jet propulsion engine and a method of operating a jet propulsion engine for propulsion of an aircraft over a wide range of speed from zero to supersonic. The engine is a turbofan type with a duct burner and with separate variable exhausts from the duct burner and from the gas turbine engine. The gas turbine core engine includes a gas generator and a low pressure turbine which drives the fan. The fan includes variable outlet guide vanes and the low pressure turbine includes a variable first-stage nozzle. The engine is operated as a normal duct burning by-pass jet engine from zero air speed up to about Mach 3. The fuel to the core engine is shut off through a transition range of speeds. Above this range the engine operates with only the duct burner supplied with fuel, with the gas generator windmilling, and with the low pressure turbine continuing to drive the fan to supercharge the duct burner, which operates as a supercharged ramjet.

Jet propulsion

A compressor or turbine rotor stage includes a wheel with a circumferential slot for retention of the roots of blades mounted on the wheel. Each side of the rim of the wheel is approximately symmetrical about a line parallel to the axis of rotation of the wheel through the centroid of the section of the rim side and is of such asymmetrical configuration about a line normal to the axis of rotation that the shear center of each side of the rim is inboard of the centroid and preferably close to or inboard of the plane of action of the radial component of the forces exerted by the blade roots on the sides of the rim due to the centrifugal force pull of the blades.

Turbomachine rotor stage

A fluid dynamic machine has a single rotor providing the rotor portion of a centrifugal compressor and also the rotor portion of an axial-to-radial flow fan. The portion of the rotor blades adjacent the hub define a compressor blading and the axially forward part of each blade is extended outwardly to provide a fan blade. These are supplied from a common inlet eye, and the flow is split at the downstream side of the fan between the fan and compressor passages by a generally radial plate curving forwardly at its inner margin and providing the forward fixed shroud for the compressor blades. The fan diffuser is split in a generally diametrical direction.

Fluid dynamic machine

A simple by-pass type jet propulsion engine includes a centrifugal compressor and a centripetal turbine mounted back-to-back and a combustion apparatus disposed radially outwardly of the turbine. These constitute the core engine; the fan part of the engine is provided by fan blades extending outwardly from the rotor blades of the core engine compressor which discharge through outlet guide vanes into a fan duct lying radially outwardly of the combustion apparatus. The fan outlet guide vanes or the fan duct nozzle may be variable to substantially close the fan duct for starting the engine. Part of the air flows from the compressor to the combustion apparatus of the core engine through hollow turbine nozzle vanes.

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Zionsville, IN, United States of America

Robert H Aspinwall