Abstract: An engine system includes a gas turbine engine with a first compressor, a first combustor, and first turbine. The engine system also includes a secondary power unit with a second compressor, a second combustor, a second turbine, a third compressor coupled to the second compressor, and an electric motor-generator, where the secondary power unit is coupled to the gas turbine engine and includes a heat exchanger. A controller is operable to determine an operating mode of the engine system, select an input energy source and an output type of the secondary power unit based on the operating mode, control the secondary power unit based on the input energy source and the output type as selected, detect a change in the operating mode of the engine system, and modify the input energy source and/or the output type of the secondary power unit based on the change in the operating mode.

Abstract: An example system includes a common electric starter controller configured to control electric starters of a plurality of gas-turbine engines that are configured to propel an aircraft, wherein the common electric starter comprises: a driver configured to generate, using electrical energy sourced from a battery of the aircraft, power signals that control the electric starters; and a plurality of bus bars configured to directly connect the common electric starter controller to the battery and transport the electrical energy from the battery to the common electric starter controller.

Abstract: A system includes a temperature control system configured to couple to an air intake section of a gas turbine system. The temperature control system includes a variable heating system having one or more heaters configured to heat an airflow in the air intake section when the airflow is cooled by an evaporative cooling system. The temperature control system is configured to control the variable heating system to vary an amount of heat supplied by the one or more heaters based on at least one temperature measurement relative to a temperature threshold.

Abstract: An auxiliary power unit (APU) includes, in serial flow communication: an engine compressor, a combustor and a turbine, the turbine rotatable about an engine axis. A first shaft operatively connects the turbine to the engine compressor and extends non-parallel to the engine axis. A second shaft operatively connects the turbine to a load and extends non-parallel to the engine axis. A method of operating an APU is also described.

Abstract: A fuel supply system for a turbine engine that provides a modulated thrust control malfunction accommodation (TCMA). The fuel supply system can include a fuel line that fluidly connects a fuel tank and the turbine engine. A fuel pump and a fuel metering valve can be fluidly connected to the fuel line. A bypass line can fluidly connect to the fuel line. Flow through the bypass line can be controlled using a bypass valve and a balancing pressure valve. The TCMA can then modulate the fuel flow using the valves.

Abstract: A method for actively calculating a capability of an electronically controlled valve is provided. The method including the steps of: a) operating the electronically controlled valve in accordance with a task; b) testing the electronically controlled valve in order to determine a range of movement of the electronically controlled valve in accordance with an initial gain, wherein the testing of the electronically controlled valve occurs after the valve has been operated in accordance with the task; c) determining a new gain required for providing a predetermined range of movement of the electronically controlled valve; and d) repeating steps a-c at least once, wherein the new gain is used to operate the valve in accordance with the task.

Abstract: In a fuel control system (10) for a gas turbine engine (1) having a gas generator (4) and a turbine (6) driven by the gas generator (4): a main fuel regulator (12) determines a demand (Wfdem) of fuel flow (Wf) to be introduced in the gas turbine engine (1), based on an input request (PLA); and a first limiter stage (14), operatively coupled to the main fuel regulator (12), causes an adjustment of the fuel flow (Wf) based on engine safety operating limits. The first limiter stage (14) is provided with a Ngdot limiter (20) to cause an adjustment of the fuel flow (Wf) when the gas generator speed rate of change (Ngdot) is determined to overcome acceleration/deceleration scheduled safety limits; the Ngdot limiter (20) implements a predictor (23), to perform a prediction (Wfdot) of the fuel flow rate of change (Wfdot), or fuel flow (Wf), allowing the gas generator speed rate of change (Ngdot) to track a scheduled reference value (Ngdotref).

Abstract: A gas turbine engine includes a casing including a plurality of interconnected casing segments defining an outer surface of the casing. One of the casing segments is a gearbox segment enclosing a gearbox and having a gearbox flange extending radially outwardly from the outer surface of the casing. The engine includes a bearing housing enclosing at least one bearing and having an annular body with an inner segment disposed within the casing. The annular body having an extension segment extending radially outwardly from the inner segment to a bearing housing flange disposed radially-outwardly of the outer surface of the casing. The bearing housing flange is engageable with the gearbox flange to removably mount the gearbox segment to the bearing housing.

Abstract: A propulsion system for an aircraft includes a turbomachine, a primary fan, and an electric machine. The turbomachine includes a first turbine and a second turbine, with at least one of the first turbine or second turbine operably connected to the electric machine and the second turbine driving the primary fan. The propulsion system additionally includes an auxiliary propulsor assembly configured to be mounted at a location away from the turbomachine and the primary fan. The electric machine is in electrical communication with the auxiliary propulsor assembly for transferring power with the auxiliary propulsor assembly during operation of the propulsion system.

Abstract: A reverse flow gas turbine engine has a low pressure (LP) spool and a high pressure (HP) spool arranged sequentially in an axial direction. The LP spool comprises an LP compressor disposed forward of an LP turbine and drivingly connected thereto via an LP compressor gear train. The HP spool comprises an HP compressor in flow communication with the LP compressor, and an HP turbine disposed forward of the HP compressor and drivingly connected thereto via an HP shaft.

Abstract: The present disclosure relates to a metallic shaft for connecting components of a gas turbine engine. Example embodiments include a metallic shaft (400) for connecting components of a gas turbine engine, the shaft (400) having a longitudinal axis (410) and comprising: a first section (401) extending from a first end (403) of the shaft (400) to a joint (405), the first section (401) composed of a material having a first thermal expansion coefficient along the longitudinal axis (410); a second section (402) extending from a second opposing end (404) of the shaft to the joint (405), the second section (402) composed of a material having a second thermal expansion coefficient along the longitudinal axis (410) that is different to the first thermal expansion coefficient.

Abstract: A fluid system for a gas turbine engine includes a first supply line, a hydraulic accessory actuable by a fluid, and a second supply line fluidly connected the hydraulic accessory and to the first supply line upstream of the component. An accumulator is fluidly connected to the second supply line upstream of the hydraulic accessory. The accumulator is operable to fill a reservoir with the fluid from the first supply line via the second supply line, and to deliver the fluid to the hydraulic accessory via the second supply line. The first supply line may be a fuel or lubricant main supply line of the engine. A method of actuating a hydraulic accessory is also disclosed.

Abstract: Isolation seals for gas turbine engines are described. The isolation seals include an elastomer body configured to be attached to a first case structure at a first end and a second case structure at a second end and a seal shield configured to be attached to the first case structure, the seal shield having a shielding member configured to define a protected space between the shielding member and the elastomer body.

Abstract: According to an aspect, a correction factor for a fuel flow of a fuel system of an engine is determined. A nominal fuel flow is determined based on a metering valve stroke. The correction factor is applied to the nominal fuel flow to produce an estimated fuel flow to control combustion in the engine.

Abstract: A power turbine control system for a gas turbine engine may comprise a controller comprising one or more processors in communication with the gas turbine engine. The processors may comprise an engine control module configured to receive a torque request signal and generate a torque achieved signal. A rate of change of power turbine speed estimation module may generate an estimated rate of change of power turbine speed signal. A dynamic inversion power turbine governor module may generate the torque request signal based on the torque achieved signal and estimated rate of change of power turbine speed signal.

Abstract: The invention relates to an assembly comprising a drive gearbox (10) for an aircraft (1) and an accessory (30), the gearbox comprising: a connecting shaft (110) adapted to be driven by the propulsion system, a main shaft (120) adapted to be driven by the connecting shaft (110), and two bevel gears (122, 123) which are integral with the main shaft (120) and have different diameters (d122, d123), the accessory comprising: a high-speed accessory shaft (31) comprising a bevel gear (310), a low-speed accessory shaft (32) comprising a bevel gear (320), such that each gear (310, 320) on the accessory shafts (31, 32) meshes with one of the two bevel gears (122, 123) on the main shaft (120), so that the two accessory shafts (31, 32) rotate at different speeds relative to one another.

Abstract: A gas turbine engine has an in-line mounted accessory gear box (AGB) and an accessory drivingly connected to the AGB, the accessory being oriented transversally to the engine centerline.

Abstract: A gas turbine engine includes a low pressure compressor, a high pressure compressor, a turbine, and a gearbox. The high pressure compressor includes a plurality of stages split into a forward portion and an aft portion. One or both of the forward portion and the aft portion of the high pressure compressor are driven by the turbine through a gearbox such that the forward portion and the aft portion may rotate at different speeds.

Abstract: The invention relates to a method for detecting a malfunction in a first turboshaft engine, referred to as an inoperative engine (4), of a twin-engine helicopter, and for controlling a second turboshaft engine, referred to as a healthy engine (5), each engine (4, 5) comprising protective stops regulated by a regulation device which define a maximum power regime, characterised in that it comprises: a step (10) of detecting an indication of failure of said inoperative engine (4); a step (11) of modifying said protective stops of said healthy engine (5) into protective stops which correspond to a maximum power single-engine regime, in the case of the detected indication of failure; a step (12) of confirming a failure of said inoperative engine (4); a step (13) of controlling an increase in the flow rate of fuel supply of said healthy engine (5), in the event of a confirmed failure.

Abstract: An assembly is provided for a gas turbine engine with an axial centerline. This assembly includes a gearbox, a first torque transmission apparatus and a second torque transmission apparatus. The gearbox includes a plurality of first gears and a plurality of second gears. The first gears are meshed together and respectively rotatable about parallel first gear axes. The second gears are meshed together and respectively rotatable about parallel second gear axes. Each of the first gear axes and each of the second gear axes is non-parallel with the axial centerline. The first torque transmission apparatus is configured to drive the first gears. The second torque transmission apparatus is configured to drive the second gears.

Abstract: A carbon dioxide compression system is disclosed. The system comprises at as a first compressor stage and a second compressor stage arranged in series, at least one inter-stage heat exchanger arranged to receive a compressed gas containing carbon dioxide flowing from the first compressor stage into the second compressor stage and to remove waste heat from the compressed gas, and an energy conversion unit, wherein at least part of the waste heat is recovered and transformed into mechanical energy.

Abstract: A system platform includes a gas turbine engine coupled to a high power generator. The high power generator, driven by the gas turbine engine, supplies power to high power subsystems of the platform.

Abstract: A combustor assembly for a gas turbine engine includes a liner and a combustor dome. The combustor dome and liner together at least in part define a combustion chamber. The combustor dome includes a transition portion and a forward wall. The transition portion extends from the forward wall towards the liner. Additionally the transition portion may define an angle relative to the forward wall and/or may define a radius of curvature between the forward wall of the combustor dome and a flat of the transition portion of the combustor dome for increasing an aerodynamic efficiency of the combustor dome.

Abstract: A gas turbine engine includes a gearbox. The gearbox includes a housing at a forward part of a core compartment of a gas turbine engine. A plurality of accessory drives are each configured to rotatably couple the gas turbine engine accessory gearbox to one of a plurality of accessory components.

Abstract: A gas turbine engine including a compressor, a turbine, and a transmission is disclosed. The turbine is coupled to the compressor to drive rotation of multiple stages of the compressor. The transmission is configured to transmit rotational power from the turbine to at least one stage of the compressor to drive rotation of the at least one stage of the compressor.

Abstract: A transition duct defining an airflow pathway between a low pressure compressor and a high pressure compressor of a gas turbine engine is disclosed. The transition duct may comprise an inner wall and an outer wall located radially outward of the inner wall with respect to a central axis of the gas turbine engine. It may further comprise a first bend configured to turn the airflow radially inward with respect to the central axis, and a turning vane located at the first bend between the inner wall and the outer wall. The turning vane may be configured to assist the first bend in turning the airflow radially inward.

Abstract: A turbomachine intermediate casing including an internal hub designed to accept a turbomachine compressor shaft, an outer shell ring, and a plurality of radial arms connecting the hub and the shell ring, one of the arms including an internal housing of radial shaft for driving auxiliary machines, the casing further includes a bevel gearbox for the radial shaft arranged in the outer shell ring, the gearbox being formed as one with the outer shell ring, and the bevel gearbox includes a housing for gears between a radial shaft and an accessories gearbox, the housing including an opening opening to the periphery of the outer shell ring.

Abstract: A gas turbine engine includes a bearing. A bearing support includes a first wall that extends between the first and second ends and is operatively supported by the bearing at a first end. An engine case is secured to the second end radially outward of the first end. A flexible support is provided by a second wall integral with and extending transversely from the first wall. The second wall has a first flange and a gear train component is secured to the first flange.

Abstract: A method of powering a rotary-wing aircraft includes selectively coupling and uncoupling a first power turbine to change a power distribution between the rotor system and the secondary propulsion system.

Abstract: A gas turbine engine with a transmission having a first rotatable member coupled to an engine spool, a second rotatable member coupled to a compressor rotor, and coupled rotatable members defining at least first and second alternate transmission paths between the first and second members. Each transmission path defines a different fixed transmission ratio of a rotational speed of the second member on a rotational speed of the first member.

Abstract: A nacelle for incorporation into a gas turbine engine has an inner wall defining a bypass duct, and an outer wall. At least one drive shaft extends through the inner wall. The at least one drive shaft is connected to a gas turbine engine receiving the nacelle. The at least one drive shaft is connected to drive at least two accessory gear boxes, with the at least two accessory gear boxes being received between the inner and outer walls of the nacelle. A gas turbine engine is also disclosed.

Abstract: A method of determining an exit temperature of a gas exiting a combustor of a gas turbine includes determining a mass flow and a temperature of fuel being delivered to the combustor; determining a mass flow and a temperature of air being delivered to the combustor, determining a temperature dependence of the specific heat capacity of a burnt mixture of the fuel and the air being delivered to the combustor; and determining an exit temperature of the burnt mixture exiting the combustor. The exit temperature is determined based on the determined mass flow and temperature of the fuel, the determined mass flow and temperature of the air, and the determined temperature dependence of the specific heat capacity of the burnt mixture.

Abstract: A gas turbine engine includes a housing including an inlet case and an intermediate case that respectively provide an inlet case flow path and an intermediate case flow path. A geared architecture is arranged within the inlet case. The geared architecture includes an epicyclic gear train. A fan is rotationally driven by the geared architecture. A shaft provides a rotational axis. A hub is operatively supported by the shaft. First and second bearings support the shaft relative to the intermediate case and the inlet case, respectively.

Abstract: Systems and methods for changing a speed ratio between a compressor boost stage (12) and at least one power turbine (16) of a gas turbine engine (10) are described. Such a system may comprise a coupling device (20) configured to selectively transmit energy from the at least one power turbine (16) to the boost stage (12) according to at least a first speed ratio and a second speed ratio. The system may also comprise an auxiliary power device (22, 26) configured to cause a rotational speed of the boost stage (12) to change from a first speed corresponding substantially to the first speed ratio to a second speed corresponding substantially to the second speed ratio when the boost stage (12) is decoupled from the at least one power turbine (16).

Abstract: A two-shaft gas turbine control system and method are provided that can enhance the efficiency and reliability thereof by controlling the amount of intake air spray and the rotational speed of a high-pressure turbine in accordance with the aperture of an inlet guide vane in a state where a two-shaft gas turbine is being operated with the efficiency of its compressor reduced. The control system includes a droplet spray device for spraying droplets to intake air for the compressor and a controller.

Abstract: This invention relates to gas turbine engines of continuous combustion in a high speed gas flow through an open circuit in high heating value gas turbine fuels. It may be used in transportation facilities, such as aviation and power plants, and also as a drive in gas compressor units. The engine contains two or more combustion chambers for high-calorific fuel suitable for combustion in speed gas and air stream. Each combustion chamber after the previous combustion chamber raises the temperature of the working body after the work at the turbine stage to the value optimal for work at next turbine stage. There is a possibility of independent reallocation of immediate bulk flows between the main stream of the working body and supplementary bypass parallel streams of the working body. For this purpose the engine, apart from the multistaged turbine, contains at least two compressor stages of air compression with bends. Each combustion chamber contains its fuel sprayers.

Abstract: A sealing component for reducing secondary airflow in a turbine system includes a first end segment configured to be disposed between, and retained in a radial direction by, a first land on a first rotor disk and a first turbine bucket platform operatively coupled to the first rotor disk. Also included is a second end segment configured to be disposed between, and retained in a radial direction by, a second land on a second rotor disk and a second turbine bucket platform operatively coupled to the second rotor disk. Further included is a main body portion extending axially from the first end segment to the second end segment.

Abstract: The invention concerns a method for a part load CO reduction operation and a low-CO emissions operation of a gas turbine with sequential combustion. The gas turbine essentially includes at least one compressor, a first combustor which is connected downstream to the compressor. The hot gases of the first combustor are admitted at least to an intermediate turbine or directly or indirectly to a second combustor. The hot gases of the second combustor are admitted to a further turbine or directly or indirectly to an energy recovery. At least one combustor runs under a caloric combustion path having a can-architecture, and wherein the air ratio (?) of the combustion at least of the second combustor is kept below a maximum air ratio (?max).

Abstract: An exemplary gas turbine engine includes a turbine section operative to impart rotational energy to a compressor section. The turbine section includes at least a low-pressure turbine and a high-pressure turbine, and a number of stages in the low pressure turbine is from three to five.

Abstract: A gas turbine engine has a fan and a turbine having a fan drive turbine rotor. The fan drive turbine rotor drives a compressor rotor. A gear reduction effects a reduction in the speed of the fan relative to an input speed from the fan drive turbine rotor that drives the compressor rotor. The compressor rotor has a number of compressor blades in at least one of a plurality of rows of the compressor rotor. The blades operate at least some of the time at a rotational speed. The number of compressor blades in at least one row and the rotational speed are such that the following formula holds true for at least one row of the compressor rotor turbine: (number of blades×rotational speed)/60 s?5500 Hz, and the rotational speed is in revolutions per minute. A method of designing a gas turbine engine and a compressor module are also disclosed.

Abstract: A turbofan engine according to an exemplary embodiment of this disclosure, among other possible things includes a gas generator section for generating a gas stream flow with higher energy per unit mass flow than that contained in ambient air, a power turbine converting the gas stream flow into shaft power, the power turbine rotating at a first relative rotational speed, a speed reduction device driven by the power turbine, and a propulsor section including a fan driven by the power turbine through the speed reduction device at a second speed lower than the first speed for generating propulsive thrust as a mass flow rate of air through a bypass flow path, wherein an Engine Unit Thrust Parameter (“EUTP”) defined as net engine thrust divided by a product of the mass flow rate of air through the bypass flow path, a tip diameter of the fan and the first relative rotational speed of the power turbine is less than about 0.15 at a take-off condition.

Abstract: The burner (1) for a gas turbine includes a duct (2) housing a plurality of tetrahedron shaped vortex generators (3) and a lance (4) to inject a fuel to be combusted. Within the duct (2), a plurality of vortex generators (3) are provided with a plurality of holes (9) for injecting cooling air. The cooling holes (9) define passing through areas that are non-uniformly distributed on a top wall (11) of the vortex generators (3). A method for locally cooling a hot gases flow passing through a burner includes non-uniformly injecting cooling air from a vortex generator into the hot gas flow in the duct, which can reduce the occurrence of flashback in the burner.

Abstract: A method of adjusting a rotational speed of the low pressure compressor rotor(s) of a gas turbine engine, including rotating the high pressure compressor rotor(s) with the high pressure turbine rotor(s) through the high pressure spool, rotating the low pressure turbine rotor(s) with a flow of exhaust gases from the high pressure turbine, rotating the low pressure spool with the low pressure turbine rotor(s), rotating a load of the engine with the low pressure spool, driving a rotation of the low pressure compressor rotor(s) with the low pressure spool through a variable transmission defining a variable transmission ratio between rotational speeds of the compressor rotor(s) and the low pressure spool, and adjusting the transmission ratio to obtain a desired rotational speed for the low pressure compressor rotor(s). A method of adjusting rotational speeds of a gas turbine engine and a gas turbine engine are also described.

Abstract: A two-shaft gas turbine having high operability is provided. The two-shaft gas turbine includes: a gas generator having a compressor, a combustor and a high pressure turbine; a power turbine having a low pressure turbine; a load connected to the power turbine; a motor/generator capable of rotatably driving the gas generator and capable of extracting power from the gas generator; electric equipment controlling the rotational driving and the power extraction by delivering electric power between the electric equipment and the motor/generator; and a control device controlling the electric equipment, wherein the combustor has a plurality of combustion regions to which a fuel is supplied through fuel adjustment means which are independent from each other, and the control device controls a delivery amount of the electric power delivered by the electric equipment corresponding to the number of combustion regions to which the fuel is supplied.

Abstract: A gas turbine engine includes first and second stages having a rotational axis. A circumferential array of airfoils is arranged axially between the first stage and the second stage. At least one of the airfoils have a curvature provided equidistantly between pressure and suction sides. The airfoils extend from a leading edge to a trailing edge at a midspan plane along the airfoil. An angle is defined between first and second lines respectively tangent to the intersection of the midspan plane and the curvature at airfoil leading and trailing edges. The angle is equal to or greater than about 10°.

Abstract: A multi-stage, two-flow, axial flow expander close-coupled to a driven machine, such as a generator. The expander includes one or more expansion stages separated by a series of flow stream dividers that separate each expansion stage into outer and inner expander flowpaths. Working fluid at a first temperature is directed into the outer expander flowpath for expansion, and working fluid at a second, lesser temperature is directed into the inner expander flowpath for expansion. Expansion of the working fluid drives the driven machine.

Abstract: A combustor system includes a pylon fuel injection system coupled to a combustion chamber and configured to inject fuel to the combustion chamber. The pylon fuel injection system includes a plurality of radial elements, each radial element having a plurality of first Coanda type fuel injection slots. A plurality of transverse elements are provided to each radial element. Each transverse element includes a plurality of second Coanda type fuel injection slots.

Abstract: A method for operating a compressed air energy storage system is provided. The method can include compressing a process gas with a compressor train to produce a compressed process gas and storing the compressed process gas in a compressed gas storage unit. The method can also include extracting the compressed process gas from the compressed gas storage unit to an expansion assembly through a feed line. A valve assembly fluidly coupled to the feed line can be actuated to control a mass flow of the compressed process gas from the compressed gas storage unit to the expansion assembly. The method can further include heating the compressed process gas in a preheater fluidly coupled to the feed line upstream from the expansion assembly, and generating a power output with the expansion assembly.

Abstract: An apparatus performs a power cycle involving expansion of compressed air utilizing high pressure (HP) and low pressure (LP) air turbines located upstream of a gas turbine. The power cycle involves heating of the compressed air prior to its expansion in the HP and LP air turbines. Taking into consideration fuel consumption to heat the compressed air, particular embodiments may result in a net production of electrical energy of ˜2.2-2.5× an amount of energy consumed by substantially isothermal air compression to produce the compressed air supply. Although pressure of the compressed air supply may vary over a range (e.g. as a compressed air storage unit is depleted), the gas turbine may run under almost constant conditions, facilitating its integration with the apparatus. The air turbines may operate at lower temperatures than the gas turbine, and they may include features of turbines employed to turbocharge large reciprocating engines.

Abstract: The invention concerns a damper arrangement for reducing combustion-chamber pulsation arising inside a gas turbine, wherein the gas turbine includes at least one compressor, a primary combustor which is connected downstream to the compressor, and the hot gases of the primary combustor are admitted at least to an intermediate turbine or directly or indirectly to a secondary combustor. The hot gases of the secondary combustor are admitted to a further turbine or directly or indirectly to an energy recovery, wherein at least one combustor is arranged in a can-architecture. At least one combustor liner includes air passages, wherein at least one of the air passages is formed as a damper neck. The damper neck being actively connected to a damper volume, and the damper volume is part of a connecting duct extending between a compressor air plenum and the combustor.