Abstract: The gas turbine engine has a bleed air aperture formed in the radially outer wall upstream from the combustor and a bearing cavity formed within the radially inner wall, at least two bearing seals enclosing at least one bearing in the bearing cavity and separating the bearing cavity from associated buffer air entry points, an oil supply system including oil paths leading to each of the bearings; a buffer air supply system including buffer air paths leading to each of the entry points and a baffle partitioning one of the entry points.

Abstract: A fluid delivery assembly for delivering fluid to a component in a gas turbine engine includes a rotating shaft having a central bore and at least one fluid exhaust in communication with the central bore for centrifugally expelling fluid, and a delivery scoop disposed around the rotating shaft and spaced apart from the rotating shaft by an annular gap. The delivery scoop includes an annular body having at least one impingement surface facing the at least one fluid exhaust and configured to scoop the fluid expelled by the at least one fluid exhaust. The impingement surface has at least one outlet for delivering the scooped fluid to the component. A method of delivering pressurised fluid in a fluid system is also presented.

Abstract: A gas turbine engine including a secondary air system with interconnected fluid passages defining at least one flow path between a common source of pressurized air and a common outlet. Some of the fluid passages deliver the pressurized air to components of the gas turbine engine. The fluid passages include a common fluid passage through which all circulation of the pressurized air to the common outlet passes. The common fluid passage has a section including a venturi configured for controlling a flow of the pressurized air from the source to the outlet. In one embodiment, the venturi is provided in a common inlet or common outlet passage. A method of pressurizing a secondary air system is also discussed.

Abstract: A compound engine assembly having an engine core including at least one internal combustion engine in driving engagement with an engine shaft, a compressor having an outlet in fluid communication with an inlet of the engine core and including at least one rotor rotatable about an axis coaxial with the engine shaft, the engine shaft in driving engagement with the compressor rotor, and a turbine section having an inlet in fluid communication with an outlet of the engine core and including at least one rotor engaged on a rotatable turbine shaft, the turbine shaft configured to compound power with the engine shaft. The turbine and engine shafts are parallel to and radially offset from one another, and the turbine shaft and the axis of the compressor rotor are parallel to and radially offset from one another. A method of driving a rotatable load of an aircraft is also discussed.

Abstract: A compound engine assembly including a compressor, an engine core including at least one rotary internal combustion engine and having an inlet in fluid communication with an outlet of the compressor, a turbine section having an inlet in fluid communication with an outlet of the engine core and configured to compound power with the engine core, and an air conduit having at least one heat exchanger extending thereacross. An outer wall of the air conduit has a plurality of openings defined therethrough downstream of the heat exchanger(s), each selectively closable by a pivotable flap movable between a retracted position where the opening is obstructed and an extended position away from the opening. Each opening defines a fluid communication between the air conduit and the ambient air when the respective flap is in the extended position. A method of directing flow through a compound engine assembly is also discussed.

Abstract: An intake assembly for a compressor providing compressed air to an internal combustion engine core, including an air conduit having at least one heat exchanger extending thereacross, an intake plenum for the compressor, a first intake conduit connected to the air conduit upstream of the heat exchanger(s), a second intake conduit connected to the air conduit downstream of the heat exchanger(s), and a selector valve configurable between a first configuration to allow a fluid communication between the intake plenum and the air conduit through the first intake conduit and a second configuration to prevent the fluid communication through the first intake conduit. Fluid communication between the intake plenum and the air conduit through the second intake conduit is allowed at least when the selector valve is in the second configuration. An engine assembly and method of supplying air to a compressor are also discussed.

Abstract: A compound engine assembly including an air conduit having an inlet in fluid communication with ambient air around the compound engine assembly, a compressor having an inlet in fluid communication with the air conduit, an engine core including at least one rotary internal combustion engine and having an inlet in fluid communication with an outlet of the compressor, a turbine section having an inlet in fluid communication with an outlet of the engine core and configured to compound power with the engine core; and at least one heat exchanger in fluid communication with the air conduit, each heat exchanger configured to circulate a fluid of the engine assembly in heat exchange relationship with an airflow from the air conduit circulating therethrough. A method of supplying air to a compound engine assembly is also discussed.

Abstract: A mid-turbine frame is disposed between high and low pressure turbine assemblies. A secondary air system is defined in the mid-turbine frame (MTF) to provide cooling to the turbine section of the engine. The secondary air system may be used to cool and pressurize seals to assist with oil retention in bearing cavities. The temperature gain of the secondary air may be reduced by flowing the secondary air through one or more external lines and then generally radially inwardly through air passages defined in the MTF.

Abstract: The gas turbine engine has a bleed air aperture formed in the radially outer wall upstream from the combustor and a bearing cavity formed within the radially inner wall, at least two bearing seals enclosing at least one bearing in the bearing cavity and separating the bearing cavity from associated buffer air entry points, an oil supply system including oil paths leading to each of the bearings; a buffer air supply system including buffer air paths leading to each of the entry points.

Abstract: A gas turbine engine having an annular gas path between a radially outer wall and a radially inner wall, leading successively across at least one compressor stage, a combustor section, and at least one turbine stage, a hollow shaft having an internal surface with an oil trap formed therein, and at least one oil recuperation orifice extending out across the hollow shaft from the oil trap; and a bearing cavity formed within the radially inner wall, having at least one bearing therein rotatably supporting the hollow shaft of the gas turbine engine, at least two bearing seals enclosing the at least one bearing in the bearing cavity and separating the bearing cavity from associated buffer air entry points, at least a first one of said buffer air entry points being exposed to the at least one oil recuperation orifice outside the hollow shaft.

Abstract: An oil supply system for a gas turbine engine with a centrifugal air/oil separator in fluid communication with the scavenge system to receive the used oil mixture and extract oil and air therefrom, a supply pump in serial connection with the main oil outlet of the separator and in fluid communication with the bearing cavities to deliver the oil thereto, an oil tank in fluid communication with the overflow oil outlet of the separator, and at least one make-up pump having an inlet in fluid communication with the tank and having an outlet in fluid communication with the scavenge system.

Abstract: An air metering apparatus for a secondary air system of gas turbine engine includes a metering gap defined between surfaces comprised of one or more metals having one of similar coefficients of thermal expansion or similar thermal expansions at an operating temperature. Provided is an air metering gap which undergoes thermal growth in a way which provides a suitable air metering gap during engine running conditions.

Abstract: A mid-turbine frame is disposed between high and low pressure turbine assemblies. A secondary air system is defined in the mid-turbine frame (MTF) to provide cooling to the turbine section of the engine. The secondary air system may be used to cool and pressurize seals to assist with oil retention in bearing cavities. The temperature gain of the secondary air may be reduced by flowing the secondary air through one or more external lines and then generally radially inwardly through air passages defined in the MTF.

Abstract: A mid turbine frame is disposed between high and low pressure turbine assemblies. A cooling air system defined in the mid turbine frame of a gas turbine engine includes internal cavities for containing pressurized cooling air to cool the inter-turbine duct and the hollow struts, and discharges the used cooling air to further cool respective high and low pressure turbine assemblies.

Abstract: An aircraft engine lubrication system has a vortex separator, a first pump line having a first pump, an inlet connected to a separated lubricant area at the outlet end of the separator, and an outlet connectable to the engine. A scavenge line is provided for returning lubricant from the engine to an inlet end of the separator. A lubricant tank is connected in fluid flow communication with the separator by a connection line. A second pump line having a second pump has an inlet connected to the lubricant tank and an outlet connected to the separator for pumping lubricant from the tank to the inlet end of the separator.

Abstract: An active tip clearance control (ATCC) apparatus of an aircraft gas turbine engine is situated within a pressurized core case of the engine. First and second portions of bypass air flow passing through the respective compressed core compartment and the ATCC apparatus, are isolated from one another in order to improve both the ATCC performance and bypass air duct performance.

Abstract: An oil supply system for a gas turbine engine with a centrifugal air/oil separator in fluid communication with the scavenge system to receive the used oil mixture and extract oil and air therefrom, a supply pump in serial connection with the main oil outlet of the separator and in fluid communication with the bearing cavities to deliver the oil thereto, an oil tank in fluid communication with the overflow oil outlet of the separator, and at least one make-up pump having an inlet in fluid communication with the tank and having an outlet in fluid communication with the scavenge system.

Abstract: An air metering apparatus for a secondary air system of gas turbine engine includes a metering gap defined between surfaces comprised of one or more metals having one of similar coefficients of thermal expansion or similar thermal expansions at an operating temperature. Provided is an air metering gap which undergoes thermal growth in a way which provides a suitable air metering gap during engine running conditions.

Abstract: A mid turbine frame is disposed between high and low pressure turbine assemblies. A cooling air system defined in the mid turbine frame of a gas turbine engine includes internal cavities for containing pressurized cooling air to cool the inter-turbine duct and the hollow struts, and discharges the used cooling air to further cool respective high and low pressure turbine assemblies.

Abstract: A gas turbine engine having a mid turbine frame comprising an annular outer case providing a portion of an engine casing; an interturbine duct (ITD) disposed within the outer case, the ITD including outer and inner rings radially spaced apart one from another and being interconnected by a plurality of radially extending and circumferentially spaced hollow strut fairings, the inner and outer rings co-operating to provide a portion of a hot gas path through the engine; a tube for delivering or discharging a lubricant fluid to or from a bearing housing, the tube extending radially through one of the hollow struts; and an insulation structure radially extending through one said hollow strut fairing, the insulation structure surrounding the tube and being spaced apart from the tube and from a hot internal surface of the one hollow strut fairing for shielding the tube from heat radiated from the hot internal surface of the one hollow strut fairing and for preventing the lubricant fluid from contacting the hot inter