Abstract: A stage of guide vanes (20) are cooled by compressor air delivered via piping (36,38) and by leakage air in the space volume (28) bounded by the combustion apparatus (14) and turbine shafting. The leakage air is drawn through tubing (40) by the compressor air which is directed over the exit ends of tubing (40) to create the necessary pressure drop in the tubing (40).

Abstract: An environmental control system for e.g. an aircraft cabin comprises ambient air pressurising compressor (16), air cooling device (30), an Air expanding turbine (26), all mounted for rotation on a common shaft (20). A main engine driven electric motor (16) provides the rotary power. An extra expansion turbine (26) is provided on shaft (20) and is connected to receive ejected, used air from cabin (18) and be driven thereby. The rotary force derived from turbine (26) is transferred via shaft (20) to the electric motor (16), thus reducing the power which otherwise would be needed from the aircraft main power plant.

Abstract: A variable cycle gas turbine engine (10) includes first and second compressors (18,16), combustion apparatus (20) and first and second turbines (22,24) operable to drive the first and second compressors (18,16) respectively via interconnecting shafts. The capacity of one of the turbines (24) may be varied, for example by means of guide vanes (32) which can be adjusted to reduce or increase a throat area (40) 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 (16) which it drives, thereby improving the surge margin of the compressor.

Abstract: A stage of guide vanes (20) are cooled by compressor air delivered via piping (36,38) and by leakage air in the space volume (28) bounded by the combustion apparatus (14) and turbine shafting. The leakage air is drawn through turbine (40) by the compressor air which is directed over the exit ends of turbine (40) to create the necessary pressure drop in the tubing (40).

Abstract: A variable cycle gas turbine engine (10) includes first and second compressors (18,16), combustion apparatus (20) and first and second turbines (22,24) operable to drive the first and second compressors (18,16) respectively via interconnecting shafts. The capacity of one of the turbines (24) may be varied, for example by means of guide vanes (32) which can be adjusted to reduce or increase a throat area (40) 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 (16) which it drives, thereby improving the surge margin of the compressor.

Abstract: 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.

Abstract: 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.