Abstract: A gas turbine engine recuperator recuperator including exhaust passages providing fluid flow communication between an exhaust inlet and an exhaust outlet, the exhaust inlet being oriented to receive exhaust flow from a turbine of the engine and the exhaust outlet being oriented to deliver the exhaust flow to atmosphere, the exhaust passages having an arcuate profile in a plane perpendicular to a central axis of the recuperator to reduce a swirl of the exhaust flow. Air passages are in heat exchange relationship with the exhaust passages and providing fluid flow communication between an air inlet and an air outlet, design to sealingly respective plenum of the gas turbine engine.

Abstract: A method of assembling a starter/generator in a gas-turbine engine, including coupling a rotor and a stator of the starter/generator such that the rotor is rotatable with respect to the stator to drive the rotor when the starter/generator is electrically powered and to produce electrical power when the rotor is rotated, securing the stator to a bearing support, coupling the starter/generator to a low pressure shaft of the engine by installing the bearing support over a bearing assembly secured to an end of the low pressure shaft, inserting the low pressure shaft through a high pressure shaft of the engine with the end of the low pressure shaft protruding therefrom and positioning the starter/generator in proximity of an end of the high pressure shaft, and drivingly engaging the rotor to the high pressure shaft.

Abstract: A recuperator disposed in the exhaust duct of a gas turbine engine includes a plurality of recuperator plates arranged in a spaced-apart relationship to define therebetween a plurality of interstices and fluid channels, the plurality of interstices adapted to direct therethrough at least one first stream received at a leading plate edge of the recuperator plates and the plurality of fluid channels adapted to direct therethrough at least one second stream to effect heat exchange between the at least one first stream and the at least one second stream. Each recuperator plate includes, formed at the leading plate edge thereof, a first concavity extending along the leading edge in a direction substantially parallel to a longitudinal axis of the plate. The first concavity extends transversely to a direction of the at least one first stream flowing over each recuperator plate.

Abstract: A bleed valve having a piston with a sealing member, the piston being displaceable between a first position to seal an aperture of a fluid conduit and an opposed second position spaced apart from the aperture to allow the working fluid therethrough. The bleed valve also has a guiding assembly with at least one guide wheel mounted to the piston and being displaceable therewith along a guide rail. The guide wheel has a guide groove extending inwardly from an outer rolling surface. The guide rail has a rail surface with a guide protrusion. The guide groove and the guide protrusion are complementary and in rolling contact with one another. The bleed valve also has a displacement mechanism for displacing the piston between the first and second positions. A compressor with a bleed valve and method for controlling bleeding of a working fluid are also discussed.

Abstract: The structural case has an annular body having a central axis and including a plurality of boss sections circumferentially interspaced from one another around the axis by a plurality of arcuate panel sections, each panel section having: two parallel arcuate structural flange members being axially interspaced from one another; a sheet metal wall extending between and interconnecting the two flange members; and at least one rib having an edge welded to the sheet-metal wall.

Abstract: A fan blade of a gas turbine engine, and a method of producing same, is disclosed which is composed of a core substrate and a nanocrystalline metal coating provided on at least a portion of the airfoil of the fan blade. The method includes the steps of providing a fan blade core having an airfoil and then applying a nanocrystalline metal coating over at least a portion of the fan blade core.

Abstract: The structural case has an annular body having a central axis and including a plurality of boss sections circumferentially interspaced from one another around the axis by a plurality of arcuate panel sections, each panel section having: two parallel arcuate structural flange members being axially interspaced from one another; a sheet metal wall extending between and interconnecting the two flange members; and at least one rib having an edge welded to the sheet-metal wall.

Abstract: A steel soft wall fan case assembly according to one embodiment configured with a thin-walled steel support structure shell including a plurality of annular axial walls of thin sheet metal reinforced by a plurality of rings interconnecting axially adjacent annular axial walls. The steel support structure shell is structurally integrated with honeycomb materials and an annular metallic inner wall. A fabric containment layer may be wrapped around one of the annular axial walls of the steel support structure shell.

Abstract: A method of diffusing and cooling an exhaust flow in an exhaust duct of a gas turbine engine includes circulating the exhaust flow from a turbine section of the gas turbine engine to a recuperator extending within the exhaust duct, circulating air discharged from a compressor section to a combustor of the gas turbine engine through air passages of the recuperator, and cooling and diffusing the exhaust flow by circulating the exhaust flow through exhaust passages of the recuperator having a progressively increasing cross-sectional area and in heat exchange relationship with the air passages.

Abstract: A method of installing a segment of a recuperator within an exhaust duct of a gas turbine engine, including positioning the segment such that its exhaust inlet is in fluid flow communication with the turbine section and its exhaust outlet is adapted to deliver an exhaust flow to atmosphere, engaging its air inlet to a plenum in fluid flow communication with the compressor discharge, and engaging its air outlet to another plenum containing the combustor. One of engaging the air inlet and engaging the air outlet includes forming a rigid connection providing sealed fluid flow communication with the corresponding plenum, and the other of engaging the air inlet and engaging the air outlet includes forming a floating connection providing sealed fluid flow communication with the corresponding plenum. The floating connection allows relative movement of the segment within the exhaust duct.

Abstract: A fan blade of a gas turbine engine is disclosed which is composed of an airfoil having a leading edge and a trailing edge, and a root with a platform and a blade fixing for engaging a fan hub. The fan blade is composed of a core substrate selected from the group consisting of composites and polymers, and an entirety of the airfoil and the root of the fan blade has a nanocrystalline metal outer layer thereon which forms an outer surface fully enveloping the fan blade. The nanocrystalline metal layer formed of a nanocrystalline metal coating has an average grain size of between 10 nm and 500 nm, and the nanocrystalline metal outer layer forms a structural element of the fan blade.

Abstract: An airfoil blade of a gas turbine engine includes a root configured for mating attachment with a cooperating rotor hub and an airfoil extending away from the root. The root is composed of a first metal and has a nanocrystalline metal coating, composed of a second metal, over at least a portion thereof. A method of protecting such a blade by applying a nanocrystalline metal coating to a portion of the blade root is also disclosed.

Abstract: A gas turbine engine recuperator including exhaust passages providing fluid flow communication between an exhaust inlet and an exhaust outlet, the exhaust inlet being oriented to receive exhaust flow from a turbine of the engine and the exhaust outlet being oriented to deliver the exhaust flow to atmosphere, the exhaust inlet having a smaller cross-sectional area than that of the exhaust outlet, and a cross sectional area of each exhaust passage progressively increasing from the exhaust inlet to the exhaust outlet such as to diffuse the exhaust flow. Air passages are in heat exchange relationship with the exhaust passages and provide fluid flow communication between an air inlet and an air outlet designed to sealingly engage respective plenums of the gas turbine engine.

Abstract: A gas turbine engine recuperator including a plurality of independent arcuate segments, each segment having an inlet connection member designed to sealingly engage a plenum in fluid flow communication with the compressor discharge, and an outlet connection member designed to sealingly engage a plenum containing the combustor. One of the inlet and outlet connection members is a rigid member forming a rigid connection to the respective plenum, and the other of the inlet and outlet connection members includes a flexible member and forms a floating connection to the respective plenum, the floating connection allowing relative movement between the segment and a remainder of the gas turbine engine.

Abstract: A casing for an aircraft engine includes an outer ring and an inner hub defining an airflow passage therebetween, the outer ring having an axis defining an axial direction; a plurality of struts arranged in a circumferential array and extending radially from the inner hub to the outer ring to mount the inner hub to the outer ring; wherein the outer ring is defined by a double skin including an axially-extending annular outer skin of sheet metal concentrically surrounding and radially-spaced from an annular inner skin of sheet metal, the outer and inner skins generally parallel to one another, an annular front end ring and an annular rear end ring welded or brazed to the outer and inner skins adjacent respective front and rear edges of the skins to define an annular cavity between them, and the outer ring further comprising a plurality of circumferentially spaced axially-extending ribs interconnecting the outer and inner skins to reinforce the double skins.

Abstract: A heat recuperator includes a plurality of channel walls composed substantially of thermally-conductive material and supported in spaced-apart relation, defining fluid channels and interstices therebetween. The fluid channels receive at least one primary fluid flow and the interstices receive at least one secondary fluid flow so as to effect heat exchange between the two flows. In use, the plurality of channel walls are deformable by pressure differential between the primary and secondary fluid flows. When at least some of the channel walls are in a deformed state, the plurality of channel walls are stabilized through press fit engagement of mutually opposed contact regions formed in adjacent pairs of the channel walls.

Abstract: A method of protecting a blade of a gas turbine engine by applying a nanocrystalline metal coating to a portion of the blade root is disclosed, which includes preparing at least a portion of a dovetail of the blade root for coating; and then applying a nanocrystalline metal coating to said portion.

Abstract: A rotor assembly for a gas turbine engine, with an annular sleeve having an inner member connected around the shaft to rotate together therewith and having an outer member with a first end connected to the inner member, the outer member defining an annular continuous frustoconical inner surface angled such as to extend closer to the central axis near the first end. A rotor disc includes an annular protuberance extending radially inwardly of the outer member and forced toward the first end, and having an annular continuous frustoconical outer surface complementary to the inner surface of the outer member and in torque-transmitting engagement therewith. The assembly includes means for axially pressing the sleeve and the disc against one another to maintain the complementary frustoconical surfaces in torque-transmitting engagement. A method of engaging a rotor disc to a driving shaft in a gas turbine engine is also provided.

Abstract: An active tip clearance control (ATCC) system of a gas turbine engine includes an ejector to selectively drive an air flow passing through the ATCC system. A high pressure air flow as a motive flow of the ejector is controlled by a valve according to engine operation requirements.

Abstract: A gas turbine engine with a rear mount assembly including link rods interconnecting the bypass duct wall and the core portion and connecting assemblies connected to the bypass duct wall. Each connecting assembly has inner and outer surfaces bordering an opening through which an outer end of a respective link rod extends. The outer surface is accessible from outside the bypass duct wall. A first locking member is engaged to the outer end in a first locked position, and includes an abutment portion located radially inwardly of the inner surface and abutting the inner surface, and an outer portion protruding radially outwardly through the opening beyond the outer surface. A second locking member is engaged the outer end in a second locked position, and has an abutment portion located radially outwardly of the outer surface and abutting the outer surface. A method of supporting a core portion is also discussed.