Abstract: A turbo blower operable in a surge area and, more particularly, a turbo blower operable in a surge area is provided. The turbo blower increases consistency of performance thereof and efficiency by preventing suspension thereof due to a temporarily generated surge by operating even in a surge area for a predetermined time in addition to a normal area in which the turbo blower normally operates.

Abstract: An apparatus and method for cooling a gas stream is provided comprising at least one heat exchanger in which a gas stream is cooled against a cooling liquid, whereby the cooling liquid temperature increases from a first temperature to a second temperature, at least one air cooler for cooling the cooling liquid after passing though the at least one heat exchanger, surface area of the at least one air cooler being designed to decrease temperature of the cooling liquid to the first temperature; a pump; and conduits to form a closed-circuit for the cooling liquid to pass continuously through the at least one heat exchanger and the at least one air cooler. The ratio of surface area of the at least one air cooler to the surface area of the at least one heat exchanger is optionally 12 or lower, and the difference of temperature between the second temperature and first temperature being greater than 15° C.

Abstract: A method and an apparatus for controlling noise of a wind turbine. The method includes: determining a noise-influencing sector of the wind turbine based on a position of the wind turbine and a position of a noise-influencing site; acquiring a current wind direction; determining whether the wind turbine under the current wind direction operates in the noise-influencing sector; and limiting output power of the wind turbine, and increasing, after the wind turbine goes out from the noise-influencing sector and the output power reaches a rated power, the output power, in a case that the determination is positive.

Abstract: The present invention provides a process for making a flow conditioning device that transforms an input flow into a desired output flow. The process includes the steps of inputting into a computer program a set of design constraints representative of the input flow and the output flow. The computer program generates a design representative of a flow-conditioning device that transforms the input flow into the output flow. The process then provides the output design to an additive manufacturing or other suitable production system adapted to form a solid representation of the flow-conditioning device.

Abstract: The impeller of a rotating machine according to at least one embodiment of the present discloser is provided with: a disc; a cover disposed on an opposite side of a radial passage from the disc in an axial direction; and a blade disposed between the disc and the cover. In a dimensionless position along a camber line of the blade when the position of a leading edge of the blade is defined as 0 and the position of a trailing edge of the blade is defined as 1, a position where an angle difference between a first blade angle at a disc-side end portion of the blade and a second blade angle at a cover-side end portion of the blade is maximum is in a range of 0.5 or more and 1 or less. The first blade angle is ?10 degrees or more and 0 degrees or less at the position where the angle difference is maximum.

Abstract: A compressor includes a housing, a shaft that is rotated relative to the housing to compress a working fluid, and a foil bearing that supports the shaft. The foil bearing includes a top foil. The foil bearing is a foil gas bearing that is backed up by a ball bearing, or a mesh foil bearing with an actuator to compress a wire mesh dampener. A heat transfer circuit includes a compressor and a working fluid. The compressor includes a shaft that is rotated to compress the working fluid, and a foil bearing for supporting the shaft as it rotates.

Abstract: A method and an apparatus for controlling noise of multiple wind turbines. The method includes: determining a noise-influencing sector of each of the multiple wind turbines, based on positions of the multiple wind turbines and a position of a noise-influencing site; acquiring a current wind direction; determining whether there is at least one wind turbine of the multiple wind turbine under the current wind direction operating in the noise-influencing sector; and limiting output power of the at least one wind turbine, in a case that the determination is positive.

Abstract: An apparatus and method regarding an airfoil for a turbine engine, the airfoil comprising an outer wall defining an interior bound by a pressure side and a suction side extending axially between a leading edge and a trailing edge defining a chord-wise direction and extending radially between a root and a tip defining a span-wise direction. The airfoil further comprising at least one cooling passage extending radially within the interior and defining a primary cooling airflow; and at least one cooling hole having an inlet defining a first cross-sectional area, the inlet in communication with the cooling passage, an outlet defining a second cross-sectional area greater than the first cross-sectional area; wherein the primary cooling airflow enters the inlet in a first direction and exits the outlet in a second direction different than the first direction.

Abstract: An endwall assembly disposed at one end of a vane assembly may comprise an endwall spar that includes an cold side, an hot side, a leading edge, a trailing edge, and an axis extending from the leading edge to the trailing edge perpendicular to the leading edge. The endwall assembly may include a coversheet on the hot side of the endwall spar and a cooling channel that includes a cooling fluid inlet disposed in the endwall spar, and a cooling fluid outlet. The endwall assembly may include a structure protruding from the cold side of the endwall spar, wherein the structure is located between the cooling fluid inlet and the cooling fluid outlet along the axis; and a cooling fluid source cavity on the cold side of the wall, the cooling fluid source cavity in fluid communication with the cooling fluid channel via the cooling fluid inlet.

Abstract: A turbine vane and a gas turbine including the same are provided. The turbine vane includes an airfoil having a pressure side and a suction side, at least one cooling channel formed radially in the airfoil, and an insert inserted into the at least one cooling channel to divide the cooling channel into a pressure side passage and a suction side passage.

Abstract: A wind power installation rotary connection, in particular a blade bearing or azimuth rotary connection, wherein the rotary connection is in the form of a plain bearing assembly, comprising an inner ring having a number of first plain bearing surfaces, an outer ring having a number of second plain bearing surfaces which are respectively associated with one of the first plain bearing surfaces as a plain bearing surface partner, and wherein the plain bearing assembly is in the form of a dry-running plain bearing assembly.

Abstract: A system is provided, including a heat management system. The heat management system includes a thermal delivery system configured to providing heating, cooling, or a combination thereof, to a first zone of a turbomachinery, and a controller operatively coupled to the thermal delivery system and configured to control the heating, the cooling, or the combination thereof, of the first zone, to minimize or to eliminate positional changes, structural changes, or a combination thereof, in one or more components of the turbomachinery due to thermal energy.

Abstract: A shroud configured to be disposed around an impeller of a centrifugal compressor, the shroud has a wall extending circumferentially around a central axis, the wall having an inner face oriented toward a gaspath and an outer face opposed to the inner face, a bleed slot defined in the wall and extending along at least a portion of a circumference thereof, the bleed slot defining a bleed direction from the inner face and away from the gaspath, the bleed direction at the inner face of the wall being either parallel to the central axis or oriented toward the central axis. A method of manufacturing a shroud is provided.

Abstract: A method of estimating an internal state of a thermal component of the invention includes a measurement step of measuring state quantity of the thermal component, an analysis-condition creation step of creating an analysis condition, a data assimilation step of obtaining probability distribution of each temperature distribution and displacement distribution through data assimilation calculation using a contraction model, a measured value, and the analysis condition, a post-processing step of obtaining the internal state of the thermal component, an analysis step of obtaining solution vectors of the temperature distribution and the displacement distribution, and a contraction-model construction step of extracting a subspace characterizing a linear space of a vector set and constructing a contraction model using the subspace, wherein, in the data assimilation step, the probability distribution is calculated using the contraction model, and, in the analysis step and the contraction-model construction step, the c

Abstract: An assembly is provided for an aircraft propulsion system. This assembly includes an inner cowl door, an outer cowl door and a flexible linkage. The outer cowl door is radially outboard of and overlaps the inner cowl door. The flexible linkage is configured to connect to and thereby link the inner cowl door and the outer cowl door.

Abstract: An airfoil includes an vane airfoil, which has a ceramic matrix composite airfoil section including an outer wall that defines an internal cavity. The vane airfoil has an associated temperature profile which defines at least one high temperature area and at least one low temperature area. The vane airfoil includes a first zone which is defined in a first radial extent and corresponds to the high temperature area of the temperature profile and a second zone defined in a second radial extent and corresponds to the low temperature area of the temperature profile. An insert is situated in the internal cavity. The insert includes a first zone defined in a first radial extent that is aligned with the first zone of the vane airfoil. The first zone includes a first plurality of cooling holes which are configured to provide a first cooling density. A second zone is defined in a second radial extent that is aligned with the second zone of the vane airfoil.

Abstract: A gas turbine engine may include a rotor overspeed protection (ROP) assembly. The ROP assembly may include an annular blade outer air seal (BOAS) assembly including a ROP segment. The ROP assembly may include a stator vane coupled with the BOAS assembly/. The stator vane may include a stator flange disposed about a forward edge portion of the stator vane. The ROP segment may include a ROP flange extending in an axially aft direction from a main body of the ROP segment toward the stator vane, wherein the ROP flange is disposed radially inward of the stator flange.

Abstract: An automatic analyzer cartridge, spinnable about a rotational axis, has fluid and aliquoting chambers, a metering chamber connected to a vent that is nearer to the rotational axis than the metering chamber, first and second ducts connecting the fluid and aliquoting chambers, and the metering and aliquoting chambers, respectively. Metering chamber side walls taper away from a central region, wherein capillary action next to the walls is greater than in the central region. Fluid flows to the metering chamber using capillary action via the second duct that has an entrance and exit in the aliquoting and metering chambers, respectively; the exit being closer to the rotational axis than the entrance. A downstream fluidic element connects to the metering chamber via a valve. A fluidic structure receives and processes a biological sample into the processed biological sample and has a measurement structure that enables measurement of the processed biological sample.

Abstract: A compressor, in particular, of a turbomachine. The compressor comprises at least one blade ring and at least two ring segments, wherein the blade ring has at least two equally large ring segments. The compressor also comprises blades, which are arranged in the ring segments of the blade ring in such a way that a first number of blades is arranged in a first ring segment and a second number of blades is arranged in a second ring segment. The first number of blades is not equal to the second number of blades.

Abstract: An anti-icing assembly includes a nozzle and a deflector plate. The nozzle includes one or more outlets configured to inject a heated fluid into an airflow along an airflow path upstream of a filter. The deflector plate is disposed upstream of the one or more outlets, wherein the deflector plate extends in a crosswise direction relative to a central axis of the nozzle to an outer edge of the deflector plate. The outer edge is offset in the crosswise direction relative to the one or more outlets, and the deflector plate is configured to spread the airflow upstream of the one or more outlets.

Abstract: Provided is a noise reduction means for a wind turbine blade comprising an active noise reduction device and a passive noise reduction device, wherein the passive noise reduction device comprises at least one serrated edge profile adapted for fixation to a trailing edge of the wind turbine blade, wherein the active noise reduction device comprises at least one unsteady pressure sensor adapted to produce an output signal corresponding to a turbulent flow condition during operation of the wind turbine blade, at least one actuator and a control unit, wherein the sensor is arranged adjacent to a serrated edge of the serrated edge profile and the control unit is adapted to control the actuator in dependence of the output signal of the sensor to emit an anti-noise signal at least partly reducing the noise generated by the wind turbine blade.

Abstract: A centrifugal compressor includes: an impeller; a main flow passage which receives the impeller and extends in a rotation axis direction of the impeller; an auxiliary flow passage which includes an upstream communication portion communicating to the main flow passage and a downstream communication portion communicating to the main flow passage at closer to the impeller than the upstream communication portion, and extends in a rotation direction of the impeller; a plurality of opening/closing portions which each have an opening portion and are arranged in the auxiliary flow passage; and a drive unit configured to move at least one of the plurality of opening/closing portions in the rotation direction.

Abstract: A diagnostic apparatus for a fuel pump diagnoses the state of a fuel pump based on: a correlation between a pump rotational speed that is a rotational speed of the motor and fuel pressure that is pressure of the fuel discharged from the fuel pump; and an initial correlation that is the correlation in an initial actuation period from when the fuel pump is energized for the first time to when a specified period has elapsed.

Abstract: An auxiliary power unit that can reduce a flow loss of gas includes: a compressor, a combustion chamber, a turbine, a turbine outlet, and a bypass duct, wherein the turbine outlet comprises an exhaust diffuser and a guide portion, wherein the bypass duct connects the compressor with the guide portion, wherein the guide portion is a channel for an air or gas and is extended radially from an outer circumferential surface of the exhaust diffuser and communicates with an inside of the exhaust diffuser via an opening, and wherein the exhaust diffuser has a first portion adjacent to a front end of the opening and a second portion adjacent to a rear end of the opening, and a radius of the second portion is larger than a radius of the first portion so that there is formed a step difference between the first portion and the second portion.

Abstract: A centrifugal compressor is configured to be used for compressing a low global warming potential (GWP) refrigerant. The centrifugal compressor comprises a casing, an impeller, and a motor for rotating the impeller. The impeller is equipped with blades having a fully nonlinear shape in a quasi-orthogonal cross-sectional view. A hub-side blade angle delta of each of the blades from a hub portion of the first impeller to a mid-span position of the blade varies along a streamwise direction such that the hub-side blade angle delta is largest at a position closer to a leading edge of the first blade than to a trailing edge of the first blade. The casing is configured such that the low global warming potential (GWP) refrigerant enters the impeller from the inlet portion along an axial direction of the impeller and exits the impeller to the outlet portion in a radial direction of the impeller.

Abstract: A component for a gas turbine engine, comprising: first and second walls; a coolant channel defined by the space between the first and second walls; and a first rib extending between the first and second walls to the end of the coolant channel in a coolant flow direction, such that the coolant channel is bifurcated in the coolant flow direction.

Abstract: Introduced herein are a dimensionless relationship between a volumetric flow rate, a head and a kinematic viscosity in a pump operation and a method that uses the dimensionless relationship to predict a viscous performance of a pump from water performance characteristics. Using the introduced dimensionless relationship, which is called Ketan's viscous head number, the introduced method determines a viscous head correlation that allows the prediction of the pump performance to be made accurately at any given speed, flow rate and viscosity. The introduced Ketan's viscous head number and method thus allow a prediction of a pump performance in a viscous application to be made from water performance characteristics without physically testing the pump in the viscous application.

Abstract: The subject matter of this specification can be embodied in, among other things, a rotary actuator that includes a first rotary actuator assembly having a first housing, a first mounting assembly radially projecting from a first longitudinal end of the first housing and defining a first axial aperture, and a first output shaft extending into the first axial aperture, a second rotary actuator assembly having a second housing, a second mounting assembly radially projecting from a second longitudinal end of the second housing and defining a second axial aperture, and a second output shaft extending into the second axial aperture, and a bearing assembly having an outer surface in contact with at least one of the first mounting assembly and the second mounting assembly, and an inner surface in contact with at least one of the first rotor assembly and the second rotor assembly.

Abstract: A turbomachine blade formed of a hollow airfoil having a leading edge and a trailing edge opposed to each other and connected by an intrados wall and an extrados wall each extending along a radial axis of the blade, between a blade root and a blade tip, and including a cooling circuit supplied with air and delivering air jets ensuring through multiple perforations of the cooling circuit an impingement cooling of the inner surface of the airfoil, the cooling circuit includes superimposed cooling channels over the height of the blade, each integrated into the inner surface of the airfoil while matching its contour, the multiple perforations being drilled in the cooling channels terminating in a purge cavity of the airfoil are able to ensure a purge of the air having impinged the inner surface of the airfoil after its passage through the perforations.

Abstract: An exemplary section of a gas turbine engine according to this disclosure includes, among other things, a first array of airfoils including a first number of airfoils, and a second array of airfoils downstream of the first array of airfoils. The second array includes a second number of airfoils. The second number of airfoils is at least 1.19 times the first number of airfoils thereby providing a predetermined modal.

Abstract: A turbocharged device including a turbocharger, a first sensor in operable communication with the turbocharger and configured to output a first signal representative of a first attribute of the turbocharger, and a controller in operable communication with the first sensor. Where the controller is configured to calculate a first preliminary surge score based at least in part on the first signal, and calculate a first weighted surge score based at least in part on the first preliminary surge score and a first weighting factor configured to express the relative significance of the first preliminary surge score.

Abstract: There is provided an air intake system for providing air to a tip clearance control system. The air intake system comprises a ram-air intake having a scoop portion and a body portion. The body portion of the ram-air intake houses a heat exchanger.

Abstract: An airfoil includes an airfoil wall that defines a leading end, a trailing end, and first and second sides joining the leading end and the trailing end. First and second ribs each connect the first and second sides of the airfoil wall. Each of the first and second ribs define a tube portion that circumscribes a rib passage and includes cooling apertures, and first and second connector arms that solely join the tube portion to, respectively, the first and second sides of the airfoil wall. The airfoil wall and the first and second ribs bound a cooling channel there between. The cooling apertures of the first and second ribs open at the cooling channel such that there is a cooling circuit in which the rib passages of the first and second ribs are fluidly connected through the cooling apertures and the cooling channel.

Abstract: An airfoil for a gas turbine engine is disclosed. In various embodiments, the airfoil includes a cooling passage; an outer wall separating a core flow path from the cooling passage; a diffuser in fluid communication with the cooling passage and opening into the core flow path, the diffuser being characterized by a linear ridge on a downstream end of the diffuser; and a thermal barrier coating covering the outer wall and the linear ridge.

Abstract: A hydraulic machine has a runner, a guide apparatus, a draft tube, and an apparatus for measuring the water level in the region of the draft tube. The apparatus includes a first pressure measuring device, a second pressure measuring device, and a unit for generating differential pressure values. The pressure measuring devices are arranged in such a way that they may detect the pressures applied inside the draft tube and are respectively connected to the unit. The first pressure measuring device is located above the second pressure measuring device, and the unit is configured to generate the difference between the pressures that the pressure measuring devices detect. There is also described a method for dewatering the runner of such a hydraulic machine.

Abstract: A turbomachine having a fan shaft supported by a first bearing positioned downstream of the fan, the first bearing including an outer ring attached to an annular support secured to the stator. The turbomachine includes at least one gas feed duct leading into an enclosure positioned against the disc, the gas feed duct being adapted to be fed at a second end with pressurized gas taken from an airstream of a high-pressure compressor of the turbomachine, so that the gas applies an axial force towards upstream on the disc during some operating phases of the turbomachine. The turbomachine further includes a ferrule imperviously sealing the enclosure.

Abstract: Method for controlling a plural stage compressor comprising at least a first stage (10), a second stage (20) and a first inter-stage line (12) between the first stage (10) and the second stage (20), comprising the steps of: a—measuring the temperature at the inlet of the compressor, b—measuring the ratio between the outlet pressure (Pout) and the inlet pressure (Pin) of the first stage (10) of the compressor, c—calculating a coefficient (?) based at least on the value of the inlet temperature (Tin) and on the measured pressure ratio (Pout/Pin), d—if the calculated coefficient (?) is in a predetermined range, acting on a control valve (70; 76; 92) mounted in a line (4; 8) supplying the inlet of the first stage (10) of the compressor or in a gas recycle line (74) which opens into the first inter-stage line (12).

Abstract: A haptic signalizing device comprises a number of piezoelectric elements arranged below a device surface such that mechanical deformations caused by the converse piezoelectric effect in the at least one piezoelectric element make the device surface to move such that the device surface follows the piezoelectric element and a driving circuit configured to cause the converse piezoelectric effect on the at least one piezoelectric element by generating an alternating electric field over the piezoelectric element in a bipolar fashion, that is, consecutively in both the same and the opposite direction with respect to the polarization of the piezoelectric element, to make the piezoelectric element to move beyond its initial position consecutively in both directions.

Abstract: A turbomachine includes a casing having an inlet end opposite an outlet end along a longitudinal axis of the casing; a shaft assembly provided within the casing, the shaft assembly extending from the inlet end to the outlet end; a plurality of rotating impellers extending radially outward from the shaft assembly; and a communication channel defined between two adjacent impellers to permit a backflow of fluid from a diffuser channel of a downstream impeller to a return channel of an adjacent upstream impeller.

Abstract: A system for generating learning data is provided. The system for generating the learning data includes a data incorporating part configured to generate new data by filtering plant data based on a warning condition to incorporate the plant data for one configuration of a plant into existing learning data and a learning data generating part configured to differentiate a weight applied to the new data and the existing learning data, respectively, by comparing the number of the new data and the number of the existing learning data, and generate new learning data by combining the new data with the existing learning data to which the weight is applied.

Abstract: A trailing edge cooling feature for a turbine airfoil (10) includes a plurality of pins (22a-l) positioned in an airfoil interior (11) toward the trailing edge 20), each extending from the pressure side (14) to the suction side (16) and further being elongated in a radial direction (R). The pins (22a-l) are arranged in multiple radial rows (A-L) spaced along the chordal axis (30), with the pins (22a-l) in each row (A-L) being interspaced to define coolant passages (24a-l) therebetween. A row of radially spaced apart partition walls (26) are positioned aft of the pins (22a-l). Each partition wall (26) extends from the pressure side (14) to the suction side (16) and is elongated in a generally axial direction, extending along the chordal axis (30) to terminate at the trailing edge (20).

Abstract: A control system for one or more wind turbines comprising an RF receiver used as a method for adaptively controlling the noise mode of operation of a wind turbine. Preferably, this involves multilateration to determine location of RF sources near wind turbindes of a wind turbine park. The RF receivers would detect nearby RF signals in multiple spectrums, in particular mobile telecommunication signals (GSM/UMTS), to identify and localize RF sources near to the wind turbine(s). This information is then be processed to identify which RF sources are likely to be linked to a real person near the wind turbine, and this can be used to adjust the noise mode of the wind turbine accordingly. Thereby maximizing energy production from the wind turbine in absence of nearby people, while keeping noise low when people are nearby.

Abstract: A gas turbine engine includes a compressor section, the compressor section including a variable inlet guide vane which is movable between distinct angles to control the airflow approaching the compressor section. A control is programmed to position the vane at startup of the engine to direct airflow across the compressor section. The engine includes a fan for delivering bypass air into a bypass duct positioned outwardly of a core engine including the compressor section. The position of the vane is configured to direct airflow across the compressor section while an aircraft associated with the gas turbine engine is in the air, and to increase a windmilling speed of the compressor section and the turbine rotors. A method and variable inlet vane are also disclosed.

Abstract: A multi-stage gas compression system useful at the production site and at central collection points, having an energy efficient and effective intercooler system. The system includes a reciprocating compressor having a plurality of compressor valves and cylinders configured in series to provide staged compression to the natural gas. Coupled with the compressor are an inlet port for receiving natural gas to be compressed, and an outlet port for delivering compressed fluid from the compressor to a discharge line, to the transmission pipeline or storage. Facilitating transmission and intercooling of the natural gas between cylinders are a plurality of pipes, each pipe in close proximity with an intercooler.

Abstract: An acoustic attenuator for a turbomachine and methodology for additively manufacturing the acoustic attenuator are provided. The acoustic attenuator includes an annular body (202) having an outer surface (204) and an inner surface (206). The inner surface of the annular body may define a bore (208) extending along a longitudinal axis (209) of the acoustic attenuator between a first end and a second end of the acoustic attenuator. The annular body may be formed by a plurality of axially-successive cross-sectional layers (e.g., 632, 634, 636) unitized between the first end and the second end of the acoustic attenuator. The plurality of axially-successive cross-sectional layers may be transversely disposed relative to the longitudinal axis of the acoustic attenuator. At least some axially-successive cross-sectional layers of the plurality of axially-successive cross-sectional layers (e.g., 632, 634, 636) defining a pocket (214) disposed between the outer surface and the inner surface of the annular body.

Abstract: A disclosed gas turbine engine includes a shroud block including a mounting slot, a blade outer air seal supported within the mounting slot and a seal disposed within the mounting slot providing a seal between the blade outer air seal and the mounting slot. An anti-rotation tab is attached to the shroud block within the mounting slot for constraining movement of the seal within the mounting slot.

Abstract: A method to monitor rotor blade vibration using unsteady casing pressure. The method applies a non-intrusive blade vibration monitoring technique by using an array of unsteady pressure sensors which may be flush-mounted in the casing of a compressor. The method comprises using spinning mode theory and temporal-spatial analysis to obtain frequency and nodal diameter information of spinning pressure waves associated with the rotor blade vibration. An example of the compressor can be a multistage axial compressor.

Abstract: The present invention provides a silencer, including: a silencer housing having an annular plate-like structure, with an annular mounting chamber formed therein; a silencing pad disposed in the mounting chamber; and a positioning portion disposed on the silencer housing and used for fastening the silencer housing. The silencer according to the embodiment of the present invention has an integrated structure, and can desirably avoid the problem of mounting unflatness in a separated structure. Moreover, the silencing pad therein is disposed to surround the entire silencer, which can provide a sound absorption and noise reduction effect more efficiently.

Abstract: A gas turbine engine generates noise during use, and one particularly important flight condition for noise generation is take-off. A gas turbine engine has high efficiency together with low noise, in particular from the bypass flow exiting the engine. The average velocity of the flow at the exit to the bypass duct is in the range of from 200 m/s to 275 m/s at a take-off lateral reference point, defined as the point on a line parallel to and 450 m from the runway centre line where the Effective Perceived Noise Level (EPNL) is a maximum during take-off.

Abstract: A gas turbine engine has a cycle operability parameter ? in a defined range to achieve improved overall performance, taking into account fan operability and/or bird strike requirements as well as engine efficiency. The defined range of cycle operability parameter ? may be particularly beneficial for gas turbine engines in which the fan is driven by a turbine through a gearbox.