Abstract: A combustor for a gas turbine engine includes a liner having a first surface, a second surface opposite the first surface, and defining a plurality of effusion cooling holes. At least one of the effusion cooling holes includes an inlet section and a converging section downstream of the inlet section. The at least one of the effusion cooling holes includes a metering section downstream of the converging section. The at least one of the effusion cooling holes includes an outlet section downstream of the metering section. The outlet section is proximate to the second surface. The inlet section, the converging section, the metering section and the outlet section extend along a longitudinal axis, with the inlet section asymmetrical relative to the longitudinal axis and the metering section symmetrical relative to the longitudinal axis.

Abstract: A gas turbine engine includes a plural spool assembly including a first spool and a second spool. The engine also includes an accessory configured to change between a motor mode and a generator mode and a transmission configured to transmit mechanical power between the accessory and at least one of the first spool and the second spool. The transmission, when the accessory is in the generator mode, is configured to transmit mechanical power from the first spool to the accessory for generating electric power at the accessory. The transmission, when the accessory is in the motor mode, is configured to transmit mechanical power from the accessory to the second spool.

Abstract: A low-leakage seal assembly for a turbomachine's combustor-turbine interface. A turbomachine includes a combustion chamber that receives compressed air for combustion from a compressor. The combustion chamber is defined by a combustion liner terminating in a seal ring where the seal ring has an enlarged head that is thicker than the remainder of the seal ring. A transition liner directs combustion gases from the combustion chamber to the turbine and has three walls forming a cavity with an open end. The seal ring extends through the open end and the head nests in the cavity. The transition liner and the seal ring are parts of a low-leakage seal assembly that is exposed on one side to the compressed air and that is exposed on another side to the combustion gases.

Abstract: A low-leakage seal assembly for a turbomachine's combustor-turbine interface. A turbomachine includes a combustion chamber that receives compressed air for combustion from a compressor. The combustion chamber is defined by a combustion liner terminating in a seal ring where the seal ring has an enlarged head that is thicker than the remainder of the seal ring. A transition liner directs combustion gases from the combustion chamber to the turbine and has three walls forming a cavity with an open end. The seal ring extends through the open end and the head nests in the cavity. The transition liner and the seal ring are parts of a low-leakage seal assembly that is exposed on one side to the compressed air and that is exposed on another side to the combustion gases.

Abstract: An engine system includes a gas generator section and a load compressor. The gas generator section includes a core compressor, a combustion assembly, and a turbine. The core compressor receives and compresses a first flow of air as first compressed air. The combustion assembly receives the first compressed air from the compressor, mixes the first compressed air with fuel, and combusts the first compressed air and fuel mixture to result in combustion gases. The turbine receives the combustion gases from the combustion assembly and extracts energy from the combustion gases. The load compressor is driven by the turbine, and it is further configured to receive and compress a second flow of air as second compressed air. At least a portion of the second compressed air is directed to the gas generator section as cooling air.

Abstract: A combustor for a gas turbine engine includes a liner having a first surface, a second surface opposite the first surface, and defining a plurality of effusion cooling holes. At least one of the effusion cooling holes includes an inlet section and a converging section downstream of the inlet section. The at least one of the effusion cooling holes includes a metering section downstream of the converging section. The at least one of the effusion cooling holes includes an outlet section downstream of the metering section. The outlet section is proximate to the second surface. The inlet section, the converging section, the metering section and the outlet section extend along a longitudinal axis, with the inlet section asymmetrical relative to the longitudinal axis and the metering section symmetrical relative to the longitudinal axis.

Abstract: A combustor for a gas turbine engine includes a first liner having a first surface, a second surface opposite the first surface, and a wall having a thickness defined between the first surface and the second surface. The first liner defines a plurality of effusion cooling holes, and at least one of the effusion cooling holes includes an inlet section spaced apart from the first surface, and a converging section downstream of the inlet section. The inlet section and the converging section are each defined so as to be outside of the thickness. The at least one of the effusion cooling holes includes a metering section downstream of the converging section and a portion of the metering section is defined within the thickness. The at least one of the effusion cooling holes includes an outlet section downstream of the metering section. The outlet section is proximate to the second surface.

Abstract: A gas turbine engine includes a plural spool assembly including a first spool and a second spool. The engine also includes an accessory configured to change between a motor mode and a generator mode and a transmission configured to transmit mechanical power between the accessory and at least one of the first spool and the second spool. The transmission, when the accessory is in the generator mode, is configured to transmit mechanical power from the first spool to the accessory for generating electric power at the accessory. The transmission, when the accessory is in the motor mode, is configured to transmit mechanical power from the accessory to the second spool.

Abstract: An engine system includes a gas generator section and a load compressor. The gas generator section includes a core compressor, a combustion assembly, and a turbine. The core compressor receives and compresses a first flow of air as first compressed air. The combustion assembly receives the first compressed air from the compressor, mixes the first compressed air with fuel, and combusts the first compressed air and fuel mixture to result in combustion gases. The turbine receives the combustion gases from the combustion assembly and extracts energy from the combustion gases. The load compressor is driven by the turbine, and it is further configured to receive and compress a second flow of air as second compressed air. At least a portion of the second compressed air is directed to the gas generator section as cooling air.

Abstract: A combustor for a gas turbine engine includes a first liner having a first surface, a second surface opposite the first surface, and a wall having a thickness defined between the first surface and the second surface. The first liner defines a plurality of effusion cooling holes, and at least one of the effusion cooling holes includes an inlet section spaced apart from the first surface, and a converging section downstream of the inlet section. The inlet section and the converging section are each defined so as to be outside of the thickness. The at least one of the effusion cooling holes includes a metering section downstream of the converging section and a portion of the metering section is defined within the thickness. The at least one of the effusion cooling holes includes an outlet section downstream of the metering section. The outlet section is proximate to the second surface.

Abstract: Auxiliary power units and methods and systems for activation and deactivation of a load compressor therein are provided. Auxiliary power unit includes the load compressor having an impeller, APU engine, coupling member, pre-spinning means, and APU controller. APU engine is adapted to be mechanically engaged to load compressor to drive load compressor to provide pneumatic power and to be disengaged when the need for pneumatic power ceases. Coupling member couples load compressor and APU engine and is configured to be controllably moved between an engaged position in which the APU engine is mechanically engaged with the load compressor, and a disengaged position, in which the APU engine is disengaged from the load compressor. APU controller is operably coupled to load compressor, APU engine, coupling member, and pre-spinning means and adapted to receive and be responsive to rotational speed signals for controlling movement of coupling member between engaged and disengaged positions.

Abstract: An axially-split radial turbine includes a forward rotor section and an aft rotor section being mechanically and abuttingly coupled to one another along an annular interface that resides within a plane generally orthogonal to a rotational axis of the axially-split radial turbine. The axially-split radial turbine can be provided as part of a gas turbine engine.

Abstract: Auxiliary power units and methods and systems for activation and deactivation of a load compressor therein are provided. Auxiliary power unit includes the load compressor having an impeller, APU engine, coupling member, pre-spinning means, and APU controller. APU engine is adapted to be mechanically engaged to load compressor to drive load compressor to provide pneumatic power and to be disengaged when the need for pneumatic power ceases. Coupling member couples load compressor and APU engine and is configured to be controllably moved between an engaged position in which the APU engine is mechanically engaged with the load compressor, and a disengaged position, in which the APU engine is disengaged from the load compressor. APU controller is operably coupled to load compressor, APU engine, coupling member, and pre-spinning means and adapted to receive and be responsive to rotational speed signals for controlling movement of coupling member between engaged and disengaged positions.

Abstract: An axially-split radial turbine includes a forward rotor section and an aft rotor section being mechanically and abuttingly coupled to one another along an annular interface that resides within a plane generally orthogonal to a rotational axis of the axially-split radial turbine. The axially-split radial turbine can be provided as part of a gas turbine engine.

Abstract: A dual alloy turbine rotor is provided and includes an integrally formed blade ring and a disk. The blade ring is made of a first alloy and includes a ring portion and a plurality of airfoils extending therefrom, where the ring portion includes an inner surface, and each airfoil includes an internal cavity formed therein. The disk is made of a second alloy and may have a beveled outer peripheral surface. The disk is disposed within the ring portion such that the disk outer peripheral surface contacts at least a portion of the ring portion inner surface. Methods of manufacturing the turbine rotor are also provided.

Abstract: A dual alloy turbine rotor is provided and includes an integrally formed blade ring and a disk. The blade ring is made of a first alloy and includes a ring portion and a plurality of airfoils extending therefrom, where the ring portion includes an inner surface, and each airfoil includes an internal cavity formed therein. The disk is made of a second alloy and may have a beveled outer peripheral surface. The disk is disposed within the ring portion such that the disk outer peripheral surface contacts at least a portion of the ring portion inner surface. Methods of manufacturing the turbine rotor are also provided.