Abstract: A method for determining the speed of at least one rotating fan, such as a propeller, through sensing pressure waves generated by the blades of the fan. An apparatus operable to execute the method is also disclosed. The apparatus includes a fan having a hub portion and a plurality of blades extending radially outward from the hub portion. The apparatus also includes an engine operable to rotate the fan about an axis of rotation. The apparatus also includes a sensor spaced from the fan along the axis of rotation. The sensor is positioned to sense at least one physical condition that is external of the engine and is changed by rotation of the plurality of blades. The sensor is operable to emit a signal corresponding to at least one physical condition. The apparatus also includes a processor operably engaged with the engine and the sensor. The processor is operable to receive the signal from the sensor and change the operation of the engine in response to the signal to change a speed of the fan.

Abstract: A method includes controlling an aircraft during descent, and controlling the engine pressure ratio of a jet engine so that the engine has a substantially equal pressure at the exhaust, and at the front of the engine during the descent.

Abstract: A method for operating a power plant to facilitate reducing emissions, wherein the power plant includes a gas turbine engine assembly and a carbon dioxide (CO2) separator. The method includes increasing an operating pressure of exhaust gas discharged from the gas turbine engine assembly, separating substantially all the CO2 entrained within the gas turbine engine utilizing the CO2 separator to produce a CO2 lean airstream, reducing the operating temperature of the CO2 lean airstream, and utilizing the cooled CO2 lean airstream to facilitate reducing an operating temperature of air entering the gas turbine engine assembly.

Abstract: An industrial gas turbine engine capable of operating at higher temperatures than air cooled nickel based alloy airfoils in the turbine. The engine burns stoichiometric or rich to produce a hot gas stream that is mostly without oxygen, and the turbine airfoils are made from a high temperature resistant material such as a refractory material that also has poor oxidation resistance. A second small gas turbine engine is used to compress nitrogen gas that is used to pass through the turbine airfoils for cooling where the film cooling nitrogen gas is injected into the hot gas stream but without igniting the fuel rich gas stream.

Abstract: In certain embodiments, a carbon capture integrated gasification combined cycle (IGCC) system includes a supplemental gas turbine engine configured to burn a high-hydrogen syngas to generate power only for an auxiliary load.

Abstract: A syngas cooler that includes an outer wall defining a cavity. A first membrane water wall is positioned within the cavity. A thermal siphon is positioned between the first membrane water wall and the outer wall and is configured to channel a flow of syngas therethrough to facilitate cooling the channeled syngas.

Abstract: A turbofan gas turbine engine is provided having a unique power off-take shaft and gear system. Other gas turbine engine types are also contemplated herein. Two power off-takes are provided, one each for the low pressure spool and high pressure spool. The power off-takes extend across a core flow path of the turbofan engine between the low and high pressure shafts to a fan frame of the turbofan. A drive gear is provided near the front end of the high pressure shaft, and another drive gear is provided on the low pressure shaft near the drive gear for the high pressure shaft. Both gears are located in a sump of the gas turbine engine. The power off-take shafts are coupled to the drive gears. Two power devices are coupled to the power off-take shafts and are located in the fan frame. The power devices can be electric generators or motors.

Abstract: A turbine engine power generation system includes a gearbox that receives rotational drive from a low spool through an input gear, in one example. The gearbox includes first and second clutches that are coupled to an input shaft of an auxiliary component, such as a generator. First and second output gears are driven at different rotational speeds by the input gear and respectively associated with the first and second clutches. An actuator selectively engages at least one of the first and second clutches to select between first and second rotational speeds in response to a command from a controller.

Abstract: A system includes a drive shaft, a motor-generator coupled to the drive shaft, a compressor coupled to the drive shaft and configured to output compressed air to a cavern, and a turbine coupled to the drive shaft and configured to receive air from the cavern. The system includes a first thermal energy storage (TES) device, a combustor configured to combust a flammable substance and generate an exhaust stream to the turbine, and controller. The controller is configured to control flow of the air to heat the air as it passes through the first TES, cause the flammable substance to flow to the combustor, operate the combustor to combust the air with the flammable substance to generate an exhaust stream into the turbine, and control the motor-generator to generate electrical energy from energy imparted thereto from the turbine via the drive shaft.

Abstract: An ACAES system operable in a compression mode and an expansion mode of operation is disclosed and includes a compressor system configured to compress air supplied thereto and a turbine system configured to expand compressed air supplied thereto, with the compressor system including a compressor conduit and the turbine system including a turbine conduit. The ACAES system also includes a plurality of thermal energy storage (TES) units positioned on the compressor and turbine conduits and configured to remove thermal energy from compressed air passing through the compressor conduit and return thermal energy to air passing through the turbine conduit. The compressor conduit and the turbine conduit are arranged such that at least a portion of the plurality of TES units operate at a first pressure state during the compression mode of operation and at a second pressure state different from the first pressure state during the expansion mode of operation.

Abstract: A power generation system includes a first compressor, a second compressor, a combustor configured to receive compressed air from the second compressor to produce an exhaust stream, a first turbine, and a power turbine. The first turbine is configured to receive the exhaust stream, generate a rotational power from the exhaust stream, output the rotational power to a second compressor, and output the exhaust stream. The system includes a coupling device configured to couple and decouple the first compressor to/from a second turbine, an electrical generator coupled to an output of the power turbine and configured to output electrical power, and a controller configured to cause the coupling device to mechanically decouple the second turbine from the first compressor, and cause the coupling device to direct compressed air from an air storage cavern to an inlet of the second compressor.

Abstract: An engine that operates and produces the entire required vehicle thrust below Mach 4 is useful for a Hypersonic combined cycle vehicle by saving vehicle and engine development costs. One such engine is a combined cycle engine having both a booster and a dual mode ramjet (DMRJ). The booster and the DMRJ are integrated to provide effective thrust from Mach 0 to in excess of Mach 4. As the booster accelerates the vehicle from Mach 0 to in excess of Mach 4, from Mach 0 to about Mach 2 incoming air delivered to the DMRJ is accelerated by primary ejector thrusters that may receive oxidizer from either on-board oxidizer tanks or from turbine compressor discharge air. As the TBCC further accelerates the vehicle from about Mach 0 to in excess of Mach 4 exhaust from the turbine and exhaust from the DMRJ are combined in a common nozzle disposed downstream of a combustor portion of said DMRJ functioning as an aerodynamic choke.

Abstract: A system comprises, a first heat recovery steam generator (HRSG) having an upstream intake duct portion, a first gas turbine engine connected to a first exhaust duct operative to output exhaust from the first gas turbine engine to the upstream intake duct portion of the first HRSG, and a second gas turbine engine connected to a second exhaust duct operative to output exhaust from the second gas turbine engine to the upstream intake duct portion of the first HRSG.

Abstract: Disclosed herein is a highly-reliable two-shaft gas turbine system in which the rotational speed of a compressor exceeds its rated rotational speed when the combustion temperature during rated operation is set to the rated combustion temperature of a simple-cycle gas turbine system and in which the drive force for the compressor can be balanced with the output from a high-pressure turbine without turbine efficiency being compromised. When the rotational speed of a compressor 1 exceeds its rated rotational speed on the condition that the combustion temperature during rated operation is set to the rated combustion temperature of a simple-cycle gas turbine system, part of the working fluid that drives turbines is diverged from a flow path that guides the working fluid to gas paths and used as a coolant.

Abstract: A gas turbo set including a first turbine, a second turbine, and a combustion chamber connected between the first and second turbines and operated by auto-ignition is provided. The turbines and the combustion chamber are located on a common shaft that may be rotated about an axis. To increase the efficiency of the gas turbo set, the outer periphery of the second turbine is at a greater distance from the axis than that of the first turbine, leading to a reduction in the size and/or the number of turbine blades.

Abstract: A method includes controlling an aircraft during descent, and controlling the engine pressure ratio of a jet engine so that the engine has a substantially equal pressure at the exhaust, and at the front of the engine during the descent.

Abstract: Disclosed is a parallel turbine arrangement including a compressor and a first turbine in operable communication with the compressor and a second turbine in operable communication with the compressor.

Abstract: A bleed system for a gas turbine engine includes: (a) a bleed air turbine having a turbine inlet adapted to be coupled to a source of compressor bleed air at a first pressure; (b) a bleed air compressor mechanically coupled to the bleed air turbine, and having a compressor inlet adapted to be coupled to a source of fan discharge air at a second pressure substantially lower than the first pressure; and (c) a mixing duct coupled to a turbine exit of the bleed air turbine and to a compressor exit of the bleed air compressor.

Abstract: A gas turbine engine having three shafts connecting respective high, intermediate and low-pressure turbines and compressors is characterised by an intermediate pressure turbine that includes two rotor stages.

Abstract: One aspect relates to a hybrid propulsive technique, comprising providing a flow of a working fluid through at least a portion of an at least one jet engine. The at least one jet engine includes an at least one turbine section, wherein the at least one turbine section includes at least one turbine stage. The at least one turbine stage includes an at least one turbine rotor and an at least one independently rotatable turbine stator. The hybrid propulsive technique further involves extracting energy at least partially in the form of electrical power from the working fluid, and converting at least a portion of the electrical power to torque. The hybrid propulsive technique further comprises rotating an at least one at least one independently rotatable turbine stator at least partially responsive to the converting the at least a portion of the electrical power to torque.

Abstract: A turbine engine, for example for a helicopter, including a gas generator and a free turbine driven in rotation by the gas flow generated by the gas generator. The turbine engine further includes a motor/generator coupled to a shaft of the gas generator, to provide a quantity of additional rotational kinetic energy to the shaft during a stage of turbine engine acceleration, or to draw a quantity of rotational kinetic energy from the shaft during a stage of turbine engine deceleration.

Abstract: In a retrofit system for hot solids combustion and gasification, a chemical looping system includes an endothermic reducer reactor 12 having at least one materials inlet 22 for introducing carbonaceous fuel and CaCO3 therein and a CaS/gas outlet 26. A first CaS inlet 40 and a first CaSO4 inlet 64 are also defined by the reducer reactor 12. An oxidizer reactor 14 is provided and includes an air inlet 68, a CaSO4/gas outlet 46, a second CaS inlet 44, and a second CaSO4 inlet 66. A first separator 30 is in fluid communication with the CaS/gas outlet 26 and includes a product gas and a CaS/gas outlet 32 and 34 from which CaS is introduced into said first and second CaS inlets. A second separator 50 is in fluid communication with the CaSO4/gas outlet 46 and has an outlet 52 for discharging gas therefrom, and a CaSO4 outlet from which CaSO4 is introduced into the first and second CaSO4 inlets 62, 66.

Abstract: A propulsive system for an aircraft including an auxiliary jet engine is integrated within a tail cone of a fuselage. Lateral air intakes include each one a scoop movable between a closed position and an opened position are associated with aerodynamic channels to supply with air the auxiliary jet engine. The aerodynamic channels meet at a common channel including a movable flap to balance air flows coming from the air intakes when the operation is not symmetrical.

Abstract: A gas turbine engine arrangement (1) comprises a first gas turbine engine (10), a second gas turbine engine (70), a differential gearbox (57) and an electrical generator (112). The differential gearbox (57) has a first input drive (54), a second input drive (78) and an output drive (110). The output drive (110) of the differential gearbox (57) is arranged to drive the electrical generator (112) via an external, accessory, gearbox (56). The external, accessory, gearbox (56) drives other accessories (116, 120). The first gas turbine (10) is arranged to drive the first input drive (54) of the differential gearbox (57) and the second gas turbine engine (70) is arranged to drive the second input drive (78) of the differential gearbox (57). The electrical generator (112) and accessories (116, 120) are driven at a constant frequency speed/frequency.

Abstract: A system for use in a combined cycle or rankine cycle power plant using an air-cooled steam condenser is provided and includes a steam turbine from which first and second steam supplies are outputted at high and low respective pressures, an air-cooled condenser configured to fluidly receive and to air-cool at least the first steam supply via a supply of air, a cooling tower from which a first water supply is cycled, a chilling coil through which a second water supply water is cycled to thereby cool the supply of air, and a vapor-absorption-machine (VAM) configured to fluidly receive the second steam supply and the first water supply by which a refrigeration cycle is conducted to thereby cool the second water supply.

Abstract: A process of energy production is disclosed. The process includes integrating three or more energy production technologies such that a first byproduct of a first energy production technology is applied to a second energy production technology and a second byproduct of the second energy production technology is applied to a third energy production technology. The process also includes operating the integrated energy production technologies to produce energy such that at least a portion of the first byproduct is utilized in an operation of the second energy production technology and a portion of the second byproduct is utilized in an operation of the third energy production technology.

Abstract: A turbofan engine (1) includes at least one apparatus (30) for driving at least one generator (22, 35), with the engine including a pre-compressor (4), at least one compressor (10) and at least two engine shafts (13, 15) rotatably arranged in an engine casing. At least one first generator (22) is coupled via an auxiliary gearbox (21) with one of the engine shafts (13) and is electrically connected to at least one accessory (23). In order to generate electrical power to such an amount in a turbofan engine (1) that stable operation of the accessories (23), in particular the compressors, is maintained also in the low-energy range, the apparatus (30) includes at least one auxiliary turbine (31) arranged between the pre-compressor (4) and the compressor (10).

Abstract: Provided is a two-shaft gas turbine with improved reliability that improves output power and efficiency and is stably operated by establishing a balance between the driving force of a compressor and the output power of a high-pressure turbine in the case where the two-shaft gas turbine is applied to a system in which the flow rate of fluid flowing into a combustor is increased compared with a simple cycle gas turbine. A portion of working fluid driving the high-pressure turbine is allowed to flow not into the high-pressure turbine but into a low-pressure turbine.

Abstract: A power generation system includes a first gas turbine system. The first turbine system includes a first combustion chamber configured to combust a first fuel stream of primarily hydrogen that is substantially free of carbon-based fuels, a first compressor configured to supply a first portion of compressed oxidant to the first combustion chamber and a first turbine configured to receive a first discharge from the first combustion chamber and generate a first exhaust and electrical energy. The power generation system further includes a second gas turbine system. The second turbine system includes a second combustion chamber configured to combust a second fuel stream to generate a second discharge, wherein the first compressor of the first gas turbine system is configured to supply a second portion of compressed oxidant to the second combustion chamber and a second turbine configured to receive the second discharge from the second combustion chamber to generate a second exhaust and electrical energy.

Abstract: While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Abstract: There is a necessity to provide power for some aircraft service functions whilst the main engines (34) are not operational, for example when the aircraft is on the ground, and to start the main engines (34). This demand is met by provision of auxiliary power units (21). Conventionally a single auxiliary power unit (2) is located in the tail of the aircraft and requires fuel lines and relatively high capacity electrical cabling in order to provide electrical power for main engine starting and service functions. The present invention provides an auxiliary power unit (21) mounted on each main engine (34) and coupled together through an electrical distribution system. This provides greater redundancy in the event of failure of an auxiliary power unit (21) as well as reducing overall weight.

Abstract: A gas turbine engine having speed an intermediate stage booster configured to provide speed change to a boost compressor. The boost compressor and fan stage are driven by a low pressure turbine; the fan stage rotates with the low pressure turbine shaft and the boost compressor rotates counter to the low pressure turbine shaft. The intermediate speed booster has an epicyclic gear train that includes an outer annulus, a sun gear, and a planetary gear, and may be engaged by a clutch in some embodiments.

Abstract: A power generating turbine system that may include: 1) a turbine that includes two sections, a high-pressure turbine section and a low-pressure turbine section that each reside on a separate shaft; 2) an axial compressor that compresses a flow of air that is then mixed with a fuel and combusted in a combustor such that the resulting flow of hot gas is directed through the turbine; 3) a two-pole generator; 4) a four-pole generator; 5) a first shaft that couples the high-pressure turbine section to the axial compressor and the two-pole generator such that, in operation, the high-pressure turbine section drives the axial compressor and the two-pole generator; and 6) a second shaft that couples the low-pressure turbine section to the four-pole generator such that, in operation, the low-pressure turbine section drives the four-pole generator.

Abstract: A power generating turbine system that may include an axial compressor that compresses a flow of air that is then mixed with a fuel and combusted in a combustor such that the resulting flow of hot gas is directed through a turbine. The turbine may include a high-pressure turbine section and a low-pressure turbine section. The high-pressure turbine section may be coupled via a first shaft to the axial compressor such that in operation the high-pressure turbine section drives the axial compressor. And, the low-pressure turbine section may be coupled via a second shaft to a low-speed generator such that in operation the low-pressure turbine section drives the low-speed generator.

Abstract: A combined cycle power plant includes a compressor, a first turbine, a second turbine, a first combustor, a second combustor, a heat exchanger and a heat recovery steam generator. A controller operates the combined cycle power plant a first mode wherein compressor air is passed through the heat exchanger before being delivered to the first and second combustors, and exhaust gas from the second turbine is passed to the heat exchanger. The exhaust gas from the second turbine pre-heats the compressor air passing through the heat exchanger to the first and second combustors.

Abstract: A power generating turbine system that includes: a turbine that includes three sections, a high-pressure turbine section, a mid-pressure turbine section, and a low-pressure turbine section that each reside on a separate shaft; 2) an axial compressor that compresses a flow of air that is then mixed with a fuel and combusted in a combustor such that the resulting flow of hot gas is directed through the turbine, the axial compressor comprising a high-pressure compressor section and a low-pressure compressor section; 3) a two-pole generator; 4) a four-pole generator; 5) a first shaft that couples the high-pressure turbine section to the high-pressure compressor section such that, in operation, the high-pressure turbine section drives the high-pressure compressor section; 6) a second shaft that couples the mid-pressure turbine section to the high-pressure compressor section and the two-pole generator such that, in operation, the mid-pressure turbine section drives the high-pressure compressor section and two-pole

Abstract: A power generating turbine system that may include: 1) a turbine that includes two sections, a high-pressure turbine section and a low-pressure turbine section that each reside on a separate shaft; 2) an axial compressor that compresses a flow of air that is then mixed with a fuel and combusted in a combustor such that the resulting flow of hot gas is directed through the turbine, the axial compressor comprising a low-pressure compressor section and a high-pressure compressor section; 3) a four-pole generator; 4) a first shaft that couples the high-pressure turbine section to the high-pressure compressor section such that, in operation, the high-pressure turbine section drives the high-pressure compressor; and 5) a second shaft that couples the low-pressure turbine section to the four-pole generator and the low-pressure compressor such that, in operation, the low-pressure turbine section drives the four-pole generator and the low-pressure compressor.

Abstract: A gas turbine engine assembly includes at least one propelling gas turbine engine and an auxiliary engine used for generating power. The propelling gas turbine engine includes a fan assembly and a core engine downstream from said fan assembly. The core engine includes a compressor, a high pressure turbine, a low pressure turbine, and a booster turbine coupled together in serial-flow arrangement such that the booster turbine is rotatably coupled between the high and low pressure turbines. The auxiliary engine includes at least one turbine and an inlet. The inlet is upstream from the high pressure turbine and is in flow communication with the propelling gas turbine engine core engine, such that a portion of airflow entering the propelling engine is extracted for use by the auxiliary engine.

Abstract: A turbine system is provided including a plurality of gas turbine engines, each having a compressor section for producing compressed air, a combustor section, and a turbine section yielding hot exhaust gas. A single, common recuperator section is shared by and operatively associated with the plurality of gas turbine engines. A first flow path within the single, common recuperator section is configured to receive compressed air produced by the compressor section of each gas turbine engine. A second flow path, separated from the first flow path and within the single, common recuperator section is configured to receive hot exhaust gases yielded by the turbine section of each gas turbine engine.

Abstract: A method facilitates assembling a gas turbine engine assembly. The method comprises providing at least one propelling gas turbine engine that includes a core engine including at least one turbine, coupling an auxiliary engine to the propelling gas turbine engine such that during operation of the propelling gas turbine engine, such that at least a portion of the airflow entering the propelling gas turbine engine is extracted from the propelling gas and channeled to the auxiliary engine for generating power, and coupling a modulating valve in flow communication to the propelling gas turbine engine to control the flow of airflow from the propelling gas turbine engine to the auxiliary engine, wherein the modulating valve is selectively operable to control an extraction point of airflow from the propelling gas turbine engine.

Abstract: Control logic, and a method implemented by the control logic, compensates for mismatched inter turbine temperatures between two gas turbine engines and displays a biased inter turbine temperature (ITT) reading to the pilot without jeopardizing the need to be properly informed of the health of all engines and the relationship engine temperature compared to the maximum allowed temperature. A temperature compensation value is added to the lower inter turbine temperature to thereby increase the ITT to a value that is substantially equal to the higher ITT value. As a result, any potential nuisance or distraction that the flight crew may experience from displaying the mismatch is eliminated.

Abstract: A combustor 10 is furnished with steam cooling piping 11. Steam is flowed by the following route, steam supply piping 20?steam cooling piping 11?steam discharge piping 70, to cool the combustor 10 with steam. When a gas turbine is stopped, valves V73, V71, V51, etc. are closed to construct a closed piping line composed of the pipings 20, 11 and 70. Then, the valve V71 is opened for evacuation by a condenser 90. Then, the valve V71 is closed, and the valve V51 is opened to charge nitrogen into the pipings 20, 11, 70. Then, the valve V51 is closed. By this procedure, residual steam within the steam cooling piping 11 can be reliably removed, and replaced by nitrogen. Thus, during stoppage of the gas turbine, residual steam can be removed reliably and promptly.

Abstract: A gas turbine engine with a turbine with an exhaust manifold thereabout from which fluids can be transferred to the turbine and an air compressor having an air transfer duct extending therefrom so as to be capable to provide compressed air in that air transfer duct at one end thereof to the air intake of an internal combustion engine provided as an intermittent combustion engine. The air intake and an exhaust outlet are each coupled to combustion chambers therein and a rotatable output shaft is also coupled to those combustion chambers for generating force. The exhaust outlet has an exhaust transfer duct extending therefrom so as to have the intermittent combustion engine be capable to provide exhaust therefrom in that exhaust transfer duct at one end thereof, and the exhaust transfer duct being connected at an opposite end thereof to the exhaust manifold to be capable of transferring intermittent combustion engine exhaust thereto.

Abstract: A dual-flow turbomachine (10), essentially comprising a fan (14), a compressor (20), a combustion chamber (21), a turbine (22) and an exhaust casing (24), which comprises an auxiliary air compressor (48) driven by a Stirling engine (53) mounted downstream of the combustion chamber (21) and having a hot chamber in thermal contact with the flow (B) of hot gases leaving the turbine and a cold chamber in thermal contact with a flow (A) of cold gases generated by the fan (14) and flowing around the turbine (22) and the exhaust casing (24).

Abstract: A multi-stage compressor, for an air separation unit comprising such a compressor and to an installation is provided.

Abstract: A representative gas turbine includes: a high pressure spool; a high pressure compressor; a high pressure turbine mechanically coupled to the high pressure spool; a lower pressure spool; a lower pressure turbine mechanically coupled to the lower pressure spool; a fan having a first set of fan blades and a second set of fan blades, the second set of fan blades being located downstream of the first set of fan blades and being operative to rotate at a rotational speed corresponding to a rotational speed of the lower pressure spool; and a gear assembly mechanically coupled to the lower pressure spool and engaging the first set of fan blades such that rotation of the lower pressure spool rotates the first set of fan blades at a lower rotational speed than the rotational speed of the second set of fan blades.

Abstract: An representative gas turbine includes: a first annular gas flow path; a second annular gas flow path located radially outwardly from the first gas flow path; in series order, a multi-stage fan, radially inboard portions of a first set of high pressure compressor blades, a second set of high pressure compressor blades, a combustion section and a high pressure turbine, positioned along the first gas flow path; and in series order, the multi-stage fan and radially outboard portions of the first set of high pressure compressor blades, positioned along the second gas flow path such that the inboard portions of the first set of high pressure compressor blades, the second set of high pressure compressor blades, the combustion section and the high pressure turbine are not positioned along the second gas flow path.

Abstract: Gas turbines with multiple gas flow paths are provided. In this regard, a representative gas turbine includes: a spool; a compressor; a turbine mechanically coupled to the spool; the compressor having a first set of blades and a second set of blades, the second set of blades being located downstream of the first set of blades, the first set of blades and the second set of blades being driven by the spool; and means for enabling the first set of blades to rotate at a lower rotational speed than the second set of blades.

Abstract: Procedure for controlling the useful life of the gas turbines of a plant by means of a production plant (10) equipped with a series of production trains (15) and an auxiliary gas generator group (40). Each production train (15) is in turn equipped with a series of gas turbine groups (20), each of which in turn includes a gas generator. The procedure comprises the following phases: a) creating a succession (20?, 20?, 20?? . . . ) of gas generator groups of gas turbines (20) to be subjected to maintenance; b) substituting the first gas generator group of gas turbines (20?) of the succession (20?, 20?, 20?? . . . ) with the auxiliary gas generator group (40), to keep the production plant (10) functioning almost continuously; c) controlling the first substituted gas generator group of gas turbines (20?), by subjecting it to ordinary maintenance operations; d) substituting the second gas generator group of gas turbines (20?) of the succession (20?, 20?, 20?? . . .

Abstract: A method facilitates assembling a gas turbine engine assembly. The method comprises providing at least one propelling gas turbine engine that includes a core engine including at least one turbine, coupling an auxiliary engine to the propelling gas turbine engine such that during operation of the propelling gas turbine engine, such that at least a portion of the airflow entering the propelling gas turbine engine is extracted from the propelling gas and channeled to the auxiliary engine for generating power, and coupling a modulating valve in flow communication to the propelling gas turbine engine to control the flow of airflow from the propelling gas turbine engine to the auxiliary engine, wherein the modulating valve is selectively operable to control an extraction point of airflow from the propelling gas turbine engine.