Abstract: Multi-engine aircraft power and propulsion systems and methods of restarting an engine of a multi-engine aircraft during fight are provided. One such method comprises: determining a condition to the effect that a flame in the combustion equipment of the second gas turbine engine has been extinguished; responsive to the determination, supplying electrical power from the electrical energy storage system to one or more of the electric machines of the second gas turbine engine and operating said one or more electric machines as motors to limit a reduction in a speed of the one or more spools of the second gas turbine engine following extinguishment of the flame in its combustion equipment; and restarting the second gas turbine engine by relighting the combustion equipment of the second gas turbine engine.

Abstract: A gas turbine engine includes a first spool, a second spool, a third spool, and a epicyclic differential. The epicyclic differential includes a sun gear, planet gears supported from a planet carrier, a ring gear, and a locking member, each housed within an accessory gearbox. The planet carrier couples to the second spool. The sun gear couples to the third spool, and the ring gear couples to engine accessories. A method of operating the gas turbine engine includes supplying a first fuel flow rate to a primary combustor associated with the first and third spools and supplying a second fuel flow rate to a secondary combustor associated with the second spool based on a power lever angle within an intermediate power level range.

Abstract: A dual-engine system of an aircraft that includes at least one main engine is provided. The dual-engine system includes a sustainer engine, a booster engine configured to augment a power output of the sustainer engine, and a gearbox coupled to the sustainer engine and the booster engine. An output of the gearbox is configured to selectively combine the power output of the sustainer engine with the booster engine.

Abstract: Systems and methods to increase intake air flow to a gas turbine engine of a hydraulic fracturing unit when positioned in an enclosure may include providing an intake expansion assembly to enhance intake air flow to the gas turbine engine. The intake expansion assembly may include an intake expansion wall defining a plurality of intake ports positioned to supply intake air to the gas turbine engine. The intake expansion assembly also may include one or more actuators connected to a main housing of the enclosure and the intake expansion assembly. The one or more actuators may be positioned to cause the intake expansion wall to move relative to the main housing between a first position preventing air flow through the plurality of intake ports and a second position providing air flow through the plurality of intake ports to an interior of the enclosure.

Abstract: A gas supply system is provided herein. The gas supply system includes a fuel oxygen reduction unit having a circuit defining a gas flowpath for a flow of a stripping gas. A reservoir is in selective fluid communication with the fuel oxygen reduction unit and is configured to store a portion of the stripping gas from the circuit. The reservoir is further configured to be in selective fluid communication with the fuel system component when installed in a vehicle to provide the stored portion of the stripping gas to the fuel system component in response to detection of a purge condition.

Abstract: The present invention discloses a novel apparatus and methods for augmenting the power of a gas turbine engine, improving gas turbine engine operation, and reducing the response time necessary to meet changing demands of a power plant. Improvements in power augmentation and engine operation include systems and methods for preheating a steam injection system.

Abstract: An apparatus is provided for a gas turbine engine. This apparatus includes a vane array and a heat exchanger integrated with the vane array. The vane array includes an inner platform, an outer platform and a plurality of vanes. The inner platform extends circumferentially about a centerline and forms an inner peripheral boundary of a flowpath through the vane array. The outer platform extends circumferentially about the centerline and forms an outer peripheral boundary of the flowpath through the vane array. The vanes extend across the flowpath between the inner platform and the outer platform. The heat exchanger includes a passage following a tortuous trajectory along a first wall of the vane array.

Abstract: A disclosed drive assembly for an auxiliary power unit includes a first drive shaft driven by an auxiliary power unit, a second drive shaft driven by a first electric motor, a differential gear system including a ring gear driven by the second drive shaft, a and planet gears supported within a carrier attached to the ring gear. The first drive shaft and an output shaft are coupled to the planet gears and a generator is driven by the output shaft. The electric motor and the auxiliary power unit combine to drive the output shaft.

Abstract: An acoustic treatment grid intended to be mounted inside or at the outlet of a duct of a bleed valve of a turbomachine of an aircraft intended to convey a gas flow, the grid comprising a perforated plate and circular orifices traversing the perforated plate along a first direction, the orifices having a diameter and a geometrical center. Each orifice is separated from an adjacent orifice by a space, the length of which is equal to the product of the diameter of said orifice and a spacing coefficient of a value between 1.1 and 6.

Abstract: A gas turbine engine includes a fan located at a forward portion of the gas turbine engine, a compressor section and a turbine section arranged in serial flow order. The compressor section and the turbine section together define a core airflow path. A rotary member is rotatable with at least a portion of the compressor section and with at least a portion of the turbine section. An outlet guide vane assembly includes multiple outlet guide vanes located in an exhaust airflow path downstream of the turbine section. The multiple outlet guide vanes being spaced-apart circumferentially from each other over an angular range of about 360 degrees, and each multiple outlet guide vane defining a radial extent.

Abstract: An airflow arrangement for a gas turbine engine in which air can be selectively directed to and from a bypass channel of the engine and into a duct communicating air into a compressor of a gas turbine engine.

Abstract: A combustion section defines an axial direction, a radial direction, and a circumferential direction. The combustion section includes a casing that defines a diffusion chamber. A combustion liner is disposed within the diffusion chamber and defines a combustion chamber. The combustion liner is spaced apart from the casing such that a passageway is defined between the combustion liner and the casing. A fuel cell assembly is disposed in the passageway. The fuel cell assembly includes a fuel cell stack that has a plurality of fuel cells each extending between an inlet end and an outlet end. The inlet end receives a flow of air and fuel and the outlet end provides output products to the combustion chamber. The outlet end of the plurality of fuel cells extends through the combustion liner and partially defines the combustion chamber.

Abstract: A multi-engine aircraft includes first and second gas turbine engines for providing motive power to the aircraft, each of the first and second engines comprising an air system, an air pressure line extending between and fluidly connecting the air systems of the first and second engines, and a pressure wave damper communicating with the air pressure line extending between the first and second engines.

Abstract: Adjustable support links for aircraft are disclosed herein. An adjustable support link includes a first rod end including a first shaft with first external threads, a second rod end including a second shaft with a bore having first internal threads, and a barrel nut at least partially disposed in the bore of the second rod end. The barrel nut has second external threads engaged with the first internal threads. The barrel nut having a channel. The first shaft is at least partially disposed in the channel. The channel has second internal threads engaged with the first external threads of the first rod end, such that rotation of the barrel nut in a first direction causes the first and second rod ends to move toward each other and rotation of the barrel nut in a second direction causes the first and second rod ends to move away from each other.

Abstract: A method of determining an inlet total air pressure includes determining a first parameter indicative of a first inlet total air pressure. The method includes executing a sequence that includes: determining a mass air flow passing through the air inlet based on the first parameter, determining a Mach number of air passing through the air inlet based on the mass air flow, determining a static air pressure at the air inlet, determining an air pressure ratio based on the Mach number, generating a subsequent parameter indicative of the revised inlet total air pressure based on the air pressure ratio and the static air pressure, and substituting the subsequent parameter for the first parameter. The method includes executing at least one additional instance of the sequence with the subsequent parameter, and outputting the subsequent parameter as the inlet total air pressure.

Abstract: A system for multiple burns from a solid fuel rocket motor may extinguish rocket fuel after the rocket has been ignited. The motor may be extinguished via rapid decompression of the combustion chamber. The fuel may then be reignited by a suitable igniter, and the process of extinguishing and reigniting may be repeated, enabling multi-burn maneuvers. A decompressive extinguishing plug nozzle may extinguish solid rocket fuel after the rocket has been ignited and/or keep a rocket in a disarmed (zero thrust) state until the rocket is to be armed. The nozzle may include a plug that mostly impedes the opening of the nozzle and an outer cowl that is movable to rapidly decompress the combustion chamber. This rapid decompression extinguishes the solid rocket fuel. In some aspects, the fuel can be reignited and extinguished multiple times.

Abstract: A hot fairing structure for a pre-diffuser includes a ring-strut-ring structure that comprises a multiple of hollow struts and a multiple of inlets to a respective diffusion passage, one of the multiple of inlets formed between each one of the multiple of hollow struts located between two diffusion passages.

Abstract: A turbine casing for an exhaust-gas turbine is provided herein. The turbine casing has a connection flange for bearing-casing-side attachment to a bearing casing in which casing-connection holes that are mutually spaced in the circumferential direction are provided, wherein, between adjacent casing-connection holes, material recesses that are open radially inwards towards a central longitudinal axis of the turbine casing are provided in the connection flange. Further provided herein is an exhaust-gas turbine that is equipped with the turbine casing.

Abstract: An orifice pack is provided for delivering pressurized air to a compressor bleed valve of a gas turbine engine. The orifice pack has a diffusion chamber in serial flow communication with a tapering passage and a first outlet passage for venting a first portion of the pressurized air from the diffusion chamber. A second outlet passage branches off from the diffusion chamber at an axial location between the inlet and the tapering passage. The second outlet passage is fluidly connected to the compressor bleed valve for directing a second portion of the pressurized air from the diffusion chamber to the compressor bleed valve.

Abstract: A pilot nozzle for a dual fuel turbine engine includes an inner air circuit, a gaseous fuel circuit radially outward from the inner air circuit, a liquid fuel circuit radially outward from the inner air circuit, an outer air circuit radially outward from the liquid fuel circuit and the gaseous fuel circuit, and a shroud radially outward from the outer air circuit. The shroud is configured to stabilize a pilot re-circulation zone downstream from outlets of the inner and outer air circuits and the liquid and gaseous fuel circuits.