Rolls-Royce Corporation

Richard J Flatman

Christopher Freeman

William B Wright

A stage of guide vanes () are cooled by compressor air delivered via piping () and by leakage air in the space volume () bounded by the combustion apparatus () and turbine shafting. The leakage air is drawn through tubing () by the compressor air which is directed over the exit ends of tubing () to create the necessary pressure drop in the tubing ().

Gas turbine cooling system

A variable cycle gas turbine engine ( ) includes first and second compressors ( ), combustion apparatus ( ) and first and second turbines ( ) operable to drive the first and second compressors ( ) respectively via interconnecting shafts. The capacity of one of the turbines ( ) may be varied, for example by means of guide vanes ( ) which can be adjusted to reduce or increase a throat area ( ) through which air leaves the guide vanes to impact the turbine. The capacity of the turbine may be increased at low engine speeds, to reduce the pressure ratio across the turbine and across the compressor ( ) which it drives, thereby improving the surge margin of the compressor.

Cycle gas turbine engine

The invention relates to turbopropeller gas turbine engines of the type which have a propeller positioned upstream of the gas generator. Intake openings supply air through intake ducts and annular intake duct to the gas generator. A separating duct removes foreign bodies from the air flowing through an outlet. The separating duct has a plurality of ejector nozzles equi-spaced in the wall of the duct. The ejector nozzles induce a flow through the separating duct to draw the foreign bodies through the separating duct. The separating duct allows the passage of large foreign bodies therethrough without damage to the ejector nozzles. The ejector nozzles are supplied with air from a compressor of the gas generator, and this allows control of the flow through the separating duct by a valve.

Gas turbine engine

The invention is particularly concerned with the control of blade tip clearance in high pressure compressors of gas turbine engines. The compressor comprises a rotor assembly having radially extending rotor blades and a stator assembly. The stator assembly comprises an inner casing and a cylindrical wall member spaced radially from the inner casing to form a chamber. The axial ends of the cylindrical wall member seal with and are moveable radially with respect to the inner casing. The casing has radially inner and radially outer stops to limit radial movement of the cylindrical wall member. The cylindrical wall member carries a ring of shroud segments which are spaced radially from the rotor blades by a clearance. A valve supplies relatively high pressure air from the downstream end of the compressor into the chamber to contract the cylindrical wall member onto the inner stops to give optimum clearance during cruise, or connects the chamber to relatively low pressure air in the fan duct by aperture in outer casing by pipes to allow the cylindrical wall member to expand to the outer stops to prevent rubbing during transients.

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Derby, United Kingdom

Richard J Flatman