Abstract: A disclosed gas turbine engine includes a first electric motor assembly that provides a first drive input for driving fan blades about an axis. A geared architecture is driven by a turbine section and is coupled to the fan section to provide a second drive input for driving the fan blades. A second electric motor assembly is coupled to rotate the geared architecture relative to a fixed structure for controlling a speed of the fan blades provided by a combination of the first drive input and the second drive input.

Abstract: A water change system comprises a water change device that performs automated water changes. The water change device automatically drains an amount of water needing replacement from a reservoir and replenishes the reservoir with a predetermined amount of clean water. The water change device comprises a reservoir port, an output port, an input port, a controller, and an enclosure. In a draining mode, water is pumped from the reservoir, through the reservoir port and into a drain or output tank via the output port. In the reservoir filling mode, clean water from an input tank or water source is pumped into the input port of the water change device and to the reservoir via the reservoir port. The water change device automatically performs water changes in accordance with a water change schedule or in response to user input. The water change device is configurable via a touch display or remotely.

Abstract: A gas turbine engine for an aircraft includes an engine core including a turbine, compressor, and core shaft connecting turbine to compressor; a fan located upstream of the engine core and including a plurality of fan blades each having a leading and trailing edge. The turbine includes a lowest pressure turbine stage having a row of rotor blades, each rotor blades extending radially and having a leading and trailing edge. The engine has a fan tip axis that joins a radially outer tip of the leading edge of a fan blade and the radially outer tip of the trailing edge of a rotor blade of the lowest pressure stage. The fan tip axis lies in a longitudinal plane which contains a centreline of engine. A fan axis angle is defined as the angle between fan tip axis and centreline, and is in a range between 10 and 20 degrees.

Abstract: The present disclosure is related to energy-harvesting articles of footwear, and associated components and methods. In some embodiments, an energy-harvesting article of footwear comprises a compressible bladder, a pneumatic motor fluidically connected to the compressible bladder, and an electric generator operatively coupled to the pneumatic motor. In some embodiments, energy is harvested by compressing a compressible bladder and flowing fluid from the compressible bladder through a pneumatic motor to generate power. Certain embodiments relate to pneumatic motor designs, and/or to methods of flowing fluid input through pneumatic motors.

Abstract: A jet propulsion system for a watercraft includes a duct defining an inlet, a venturi unit, an impeller housing disposed between the inlet and the venturi unit, and an impeller disposed within the impeller housing. The impeller is rotatable in a forward direction and a reverse direction. The venturi unit includes a venturi conduit and at least one door connected thereto. The venturi conduit has a peripheral wall defining at least one aperture. The at least one door is movable between a closed position when the impeller rotates in the forward direction, and an open position when the impeller rotates in the reverse direction. In the closed position, the at least one door closes the at least one aperture. In the open position, the at least one door opens the at least one aperture such that water flows into the venturi conduit via the at least one aperture.

Abstract: A sump pump system having a primary pump, a fluid level sensor, and a primary controller electrically connected to the primary pump for activating the pump when the fluid level sensor indicates a predetermine fluid level has been reached, the primary controller having a primary interface for communicating with a secondary pump. In some forms, the system includes a secondary pump having a secondary controller electrically connected to the secondary pump and having a secondary interface, the primary and secondary interfaces allowing the primary and secondary pump controllers to communicate with one another and allowing at least one of the primary and secondary pump controllers to assume control of both the primary and secondary pump. Related methods are further described herein.

Abstract: A coolant pump for an internal combustion engine includes a delivery duct, a drive shaft, a coolant pump impeller arranged on the drive shaft to covey a coolant into the delivery duct, a control slide which controls a cross-section of an annular gap arranged between an outlet of the coolant pump impeller and the delivery duct, a side channel pump with a side channel pump impeller arranged on the drive shaft and a side channel, a pressure duct comprising a cross-section which fluidically connects an outlet of the side channel to a first pressure chamber of the control slide, a valve which opens and closes the cross-section of the pressure duct, and a first housing part arranged to have the side channel be formed therein and the control slide slidingly guided thereon. The coolant pump impeller is integrally formed with the side channel pump impeller.

Abstract: A booster assembly for a gas turbine engine having a first rotor assembly comprising a low pressure turbine drivingly connected to a fan via a first shaft and a second rotor assembly comprising a second turbine drivingly connected to a high pressure compressor via a second shaft. The first and second rotor assemblies are arranged to undergo relative rotation in use about a common axis. The booster assembly comprises a further compressor arranged to be disposed about said common axis between the fan and high-pressure compressor in a direction of flow and a gearing having first and second input rotors and an output rotor. The first input rotor is arranged to be driven by the first rotor assembly and the second input rotor is arranged to be driven by the second rotor assembly such that the output rotor drives the further compressor in dependence upon the difference in rotational speed between the first and second rotor assemblies.

Abstract: A booster assembly for a gas turbine engine having a first rotor assembly comprising a low pressure turbine drivingly connected to a fan via a first shaft and a second rotor assembly comprising a second turbine drivingly connected to a high pressure compressor via a second shaft. The first and second rotor assemblies are arranged to undergo relative rotation in use about a common axis. The booster assembly comprises a further compressor arranged to be disposed about said common axis between the fan and high-pressure compressor in a direction of flow and a gearing having first and second input rotors and an output rotor. The first input rotor is arranged to be driven by the first rotor assembly and the second input rotor is arranged to be driven by the second rotor assembly such that the output rotor drives the further compressor in dependence upon the difference in rotational speed between the first and second rotor assemblies.

Abstract: A gas turbine engine assembly according to an exemplary aspect of the present disclosure includes, among other things, a geared architecture configured to rotatably couple a turbine and a compressor of an engine to rotate the compressor at a different speed than the turbine and a fan.

Abstract: A liquid cooling heat dissipation structure includes a heat-conducting substrate, a fluid-splitting board, a fluid-conducting board, and a liquid supply module. The heat-conducting substrate has a heat-conducting body contacting a heat generation source and a plurality of heat-dissipating fins disposed on the heat-conducting body. The fluid-splitting board is disposed on the heat-dissipating fins. The fluid-conducting board is disposed on the fluid-splitting board. The liquid supply module includes an external cover body detachably disposed on the heat-conducting body and at least two pumps detachably disposed on the external cover body. The external cover body has at least one liquid inlet and at least one liquid outlet, and cooling liquid flows into the external cover body through the at least one liquid inlet and flows out of the external cover body through the at least one liquid outlet by driving one or all of the at least two pumps.

Abstract: A marine power generation apparatus is provided for generating power from an ocean current. The apparatus includes a turbine operable to generate power when within an ocean current. The turbine includes a pair of turbine blade assemblies each having a hub, a set of turbine spokes, stays or blades extending radially from the hub; and a circumferential ring extending around and connected to an outer periphery of the set of turbine spokes, stays or blades. The pair of turbine blade assemblies is mounted for same-direction rotation when placed in an ocean current and each being coupled with a common turbine shaft or a turbine shaft assembly. In addition, the turbine shaft is coupled along a shared axis with a rotor or an electrical generator. Means is also provided for anchoring the power generation means relative to a floor of the ocean and in alignment with the ocean current.

Abstract: A centrifugal pump incorporates multiple impellers which are driven by a shaft at constant speed. To engage an impeller, a ball end rod is operated, which interacts with an integral structure which comprises a disc, connector or a support collar, and face gear as linking means. The integral structure is further coupled with the impeller. During engagement, a linking means which is mounted on the impeller and also on the integral structure get coupled together resulting in engaging the impeller for rotation. The impellers can be engaged and disengaged according to the flow requirements thereby saving the energy.

Abstract: It is intended to effectively cool a dummy ring and a rotor disposed on the inner side of the dummy ring of a single-flow turbine and to suppress a decrease in thermal efficiency by preventing main steam from leaking to the dummy ring side. A cooling steam supply pipe 32 is provided in the dummy ring 26 of the single-flow turbine 10A and extraction steam of a boiler at 570° C. or below is supplied to a clearance c between the dummy ring 26 and the turbine rotor 12 as cooling steam S4. The cooling steam S4 has lower temperature and higher pressure than leak steam S2 which is a portion of the main steam S1 leaking to the dummy ring 26 side. By supplying the cooling steam S4, the leak steam S2 is prevented from entering the dummy ring 26 side and the dummy ring 26, a welding part w and a second rotor part 12b with low heat resistance that are disposed on the inner side of the dummy ring 26 can be cooled.

Abstract: A fan system for a variable air volume heating and/or air conditioning unit comprising a fan array with a control system to eliminate surge at low operating flows and to maximize operating range. The fan control system includes a fan pressure sensor for determining the pressure rise across the fan array and a fan airflow sensor for determining the total airflow generated by the fan array. A surge controller is programmed to constantly monitor the calculated surge pressure as the fan speed control is modulating the fan speed in response to user demands. As airflow increases or decreases in response to changes in fan speed, so will the calculated surge pressure. The surge control turn fans on and off to ensure that the operating fans are running in their optimum fan speed ranges. Thus, the fans in the fan array are prevented from reaching the surge point.

Abstract: A modular fan housing configured to hold an array of motors and fans is provided. The modular fan housing is configured for use in an air-handling system that delivers air to a ventilation system for at least a portion of a building. The fan housing comprises a plurality of modular units configured to be stacked adjacent to one another in at least one row or column to form an array. The modular units each include an interior surface and have a front end and a back end that define a chamber. The chambers are configured to receive the motors and fans. Sound attenuation layers extend along at least a portion of the interior surface of the corresponding chambers. The sound attenuation layers are positioned between at least some of the adjacent chambers.

Abstract: A modular fan housing configured to hold an array of motors and fans is provided. The modular fan housing is configured for use in an air-handling system that delivers air to a ventilation system for at least a portion of a building. The fan housing comprises a plurality of modular units configured to be stacked adjacent to one another in at least one row or column to form an array. The modular units each include an interior surface and have a front end and a back end that define a chamber. The chambers are configured to receive the motors and fans. Sound attenuation layers extend along at least a portion of the interior surface of the corresponding chambers. The sound attenuation layers are positioned between at least some of the adjacent chambers.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.

Abstract: A turbofan engine includes a fan, a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, a shaft configured to be driven by the turbine section and coupled to the compressor section through a first torque load path, and a speed reduction mechanism configured to be driven by the shaft through a second torque load path separate from the first load path for rotating the fan.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.

Abstract: A modular fan housing configured to hold an array of motors and fans is provided. The modular fan housing is configured for use in an air-handling system that delivers air to a ventilation system for at least a portion of a building. The fan housing comprises a plurality of modular units configured to be stacked adjacent to one another in at least one row or column to form an array. The modular units each include an interior surface and have a front end and a back end that define a chamber. The chambers are configured to receive the motors and fans. Sound attenuation layers extend along at least a portion of the interior surface of the corresponding chambers. The sound attenuation layers are positioned between at least some of the adjacent chambers.

Abstract: A modular fan array is provided that is configured for use in an air-handling system and configured to deliver air to a ventilation system for at least a portion of a building. The modular fan array comprises a plurality of modular units configured to be stacked adjacent to one another in at least one row or column to form an array. The modular units each include at least an interior surface, a front end and a back end that define a chamber. The modular fan array includes motors and fans positioned in the chambers of the modular units. The fans are located proximate to the front ends of the corresponding chambers. The fans direct air to discharge from the back ends of the chambers. Sound attenuation layers extend along at least a portion of the interior surface of the chambers. The sound attenuation layers are positioned between at least some of the adjacent chambers.

Abstract: The turbocharger having a device for detecting a malfunction of the turbocharger, particularly a malfunction of at least one bearing of the turbocharger has the following features: The device for detecting a malfunction of the turbocharger has a memory device, in which the target operating states of an intact turbocharger are stored. The device for detecting a malfunction of the turbocharger further has a comparing device, in which the determined actual operating state of the turbocharger is compared to a corresponding target operating state of an intact turbocharger. The turbocharger further has a measuring device for determining an actual operating state of the turbocharger, wherein the device for detecting a malfunction of the turbocharger emits an error message if the comparing device detects that the actual operating stage deviates from the target operating state by a predefined measure.

Abstract: A serial axial fan preferably includes a first impeller and a second impeller each having a plurality of blades radially extending with a predetermined rotation axis as the center, a first motor portion, a second motor portion, a first housing, and a second housing. The first motor portion has a first circuit board on which at least one electronic component arranged to control the driving of the first impeller is mounted. The second motor portion has a second circuit board on which at least one electronic component arranged to control the driving of the second impeller is mounted. The first and second circuit boards are electrically connected. The driving of the first impeller and the driving of the second impeller are controlled by the electronic component disposed on at least one of the first and second circuit boards.

Abstract: Improvements in a transmission are provided for transferring power from a power source to a work unit. The pump transfers energy received from the power source into a fluid or gas. The first turbine is fixed to output shaft, and a plurality of additional turbines are fixed on either one-way overrunning clutches or multi-disc clutches and these clutches are fixed to the output shaft and after each turbine is a multi-valves that discharges the fluid or gas. After all of the multi-stage turbines a first planetary gear set connects the transmission to the vehicle or work unit. The second planetary gear set is located between the last turbine and the first planetary gear set. During braking the planetary gear set reverses turning direction of the turbines and convert the turbines into pumps where they will pump low pressure fluid to a high pressure accumulator.

Abstract: It is provided to embody as a modularly constructed system, a waterwheel for power generation via generators with transversely extending water blades as hinged or folding blades. In this regard it is provided to arrange the water blades over a truss framework. The truss framework for each water blade is formed by a transversely extending prism-like arrangement of plural connected struts as transverse supports, whereby these are connected at node points by longitudinal rods, and at least one strut of the transverse supports is connected with the wheel rim. In that regard, a longitudinal rod located at the top and arranged over the transverse supports is embodied for the rotatable support of a pivotably received water blade via a mounting receiver and a longitudinal rod is allocated as a counter support for the water blade in its working position. Simultaneously this longitudinal rod serves for limiting a pivoting motion of the neighboring water blade in the turbulent region.

Abstract: Provided here is a counter-rotating axial flow fan with improved air flow-static pressure characteristics and reduced power consumption and noise compared to the related art. A plurality of struts are disposed to be stationary between a front impeller and a rear impeller in an air channel. A plurality of front blades are each formed of a swept-back blade, and a plurality of rear blades are each formed of a forward-swept blade.

Abstract: A power generating apparatus suitable for use in extracting energy from the movement of water, in particular tidal movement, is disclosed. The apparatus includes an elongate, generally circular in cross section, buoyancy vessel (1), having depending from its underside on a mounting means, rotatable rotor blades (2). The rotor blades are connected to a power generating means whereby in use of the apparatus movement of water across the rotor blasé, drives them so as to generate power in the power generating means.

Abstract: A fan includes a first motor having a first rotor and a second motor having a second rotor which is rotationally connected to the first rotor. The fan further comprises a first impeller which, when driven by the first motor, rotates along a first direction and creates a main flow along a direction perpendicular to the periphery thereof and a tangential flow along the tangent thereof. The fan also includes a second impeller which, when driven by the second motor, rotates along the reverse direction of the first direction and impel the tangential flow to the direction perpendicular to the periphery of the first impeller.

Abstract: A stacked pump arrangement for mixed-media flow includes a first, self-priming, centrifugal pump with a volute having an inlet and an outlet and a second straight centrifugal pump mounted to an upper portion of the first centrifugal pump, the second straight centrifugal pump also having a volute with an inlet and an outlet. A transition chamber is connected, at one end, to the first centrifugal pump volute outlet and is connected, at another end, to the second straight centrifugal pump volute inlet.

Abstract: A stacked pump arrangement for mixed-media flow includes a first, self-priming, centrifugal pump with a volute having an inlet and an outlet and a second straight centrifugal pump mounted to an upper portion of the first centrifugal pump, the second straight centrifugal pump also having a volute with an inlet and an outlet. A transition chamber is connected, at one end, to the first centrifugal pump volute outlet and is connected, at another end, to the second straight centrifugal pump volute inlet.

Abstract: A method of operating variable pitch fans in series to cool an operating computer system. The method comprises running a first variable pitch fan with blades positioned at an operational pitch to induce airflow through the computer system and through a second variable pitch fan disposed in series with the first fan, and, simultaneously, not running the second variable pitch fan with blades positioned for minimal impedance to the airflow. In response to detecting a failure condition of the first fan, the method includes running the second fan with blades positioned at an operational pitch to induce airflow through the computer system and through the first fan, and, simultaneously, not running the first fan with blades positioned for minimal impedance to the airflow. Preferably, the method includes locking the rotor of a fan that is not running, and locking the blades of the non-running fan in a minimal impedance position.

Abstract: A fan array fan section in an air handling system includes a plurality of fan units arranged in a fan array and positioned within an air handling compartment. One preferred embodiment may include an array controller program to operate the plurality of the fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a space pattern array configuration, a checker board array configuration, rows slightly offset configuration, columns slightly offset configuration, or a staggered array configuration.

Abstract: A hybrid turbo transmission for reduced energy consumption is disclosed. A hybrid turbo transmission configured as a multi-purpose unit (MPU). The MPU recovers energy from the cooling system, exhaust system, ram pressure and the breaking system. The MPU unit is an automatic transmission, supercharger, air compressor for other uses, and starter for the engine using a multi-purpose unit that will eliminate the need for a torque converter or clutch, flywheel, catalytic converter, starter and supercharger. The MPU reduces pollution to near zero and reduces the aerodynamic drag coefficient on the vehicle. The MPU uses two or more in-line compressors to transfer power from the power source, such as an internal combustion engine (ICE) to a turbine or multi-stage turbine that acts as an automatic transmission. The hybrid turbo transmission system uses plug-in power as a second source of power.

Abstract: The present invention relates to a rotorcraft blade (1) provided with a dynamic balancing system having a balancing device (10). The balancing device (10) is embedded in the inside (INT) of the body of the blade (1) in such a manner that it does not open to the outside (EXT) of said blade (1).

Abstract: A fan assembly (20) used for dissipating heat from an electronic device. The fan assembly includes a bracket (30) and a fan module (40). The bracket has two parallel retaining walls (31). Each retaining wall defines an opening (311) and two recesses (313) at opposite sides of the opening. The fan module is received in the bracket. The fan module includes a fan (50) and a pair of clamping members (60). The fan has a pair of fan openings in alignment with the openings of the bracket for airflow flowing therethrough. The clamping members are respectively attached to opposite sides of the fan. A pair of resilient arms (67) extends out from each clamping member. Each resilient arm has an engaging portion (671) received in the corresponding recess of one of the retaining walls. The fan module is retained in the bracket via the engaging portions engaging with the recesses and being sandwiched between the retaining walls.

Abstract: An engine for powering a vehicle, such as a military aircraft or a commercial aircraft, is provided. The engine broadly comprises a main core with a plurality of spools with each spool having a plurality of compressor blades and a plurality of turbine blades attached thereto. One of the spools has a first set of fan blades attached thereto. The engine further has a variable bypass turbine fan formed by a second set of fan blades. The second set of fan blades is arranged outboard of the main core. The second set of fan blades may be decoupled from the first set of fan blades.

Abstract: A ducted fan assembly includes a housing unit, a motor, and a propeller. The housing unit includes a duct member, and a hollow seat member disposed in the duct member. The motor is mounted to an exterior of the seat member, and includes a power cord extending through the seat member. The propeller is mounted to the motor and is driven thereby to generate an airflow that flows through the duct member and that acts on the motor.

Abstract: Solutions for clutching turbine wheels are disclosed. In one embodiment, an apparatus includes: a turbine rotor shaft; a plurality of turbine wheels affixed to the turbine rotor shaft; an independent turbine wheel engagably attached to the turbine rotor shaft; and a clutch operably connected to the turbine rotor shaft, the clutch configured to couple and decouple the independent turbine wheel from the turbine rotor shaft.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.

Abstract: A first motor rotates, in one of two rotating directions, the first impeller including a plurality of front blades in a suction opening portion of a housing. The second motor rotates, in the other rotating direction opposite to the one rotating direction, the second impeller including a plurality of rear blades in a discharge opening portion of the housing. A plurality of stationary blades are arranged between the first impeller and the second impeller in the housing. When the number of the front blades is N, that of the stationary blades is M, and that of the rear blades is P, their relationship is defined as N>P>M. A length L1 of the front blades measured in an axial direction is set longer than a length L2 of the rear blades measured in the axial direction.

Abstract: A propulsive fan system comprises a fan unit comprising a first stage array of rotatable blades upstream of a second stage array of rotatable blades. The first stage is coupled to a first drive means. The second stage is coupled to a second drive means. The first drive means is independently operable of the second drive means during operation of the fan system.

Abstract: Solutions for clutching steam turbine low pressure sections are disclosed. In one embodiment, a system includes: a first low pressure steam turbine including a first shaft; a second low pressure steam turbine including a second shaft; a clutch for coupling and uncoupling the first shaft and the second shaft; a conduit for delivering a working fluid to the first low pressure steam turbine and the second low pressure steam turbine; a valve within the conduit, the valve having an open position and a closed position, the closed position preventing flow of the working fluid to the second low pressure steam turbine; and a controller for operating the clutch and the valve, the controller uncoupling the second shaft from the first shaft and closing the valve in response to the first and second low pressure steam turbine attaining a predetermined low part load.

Abstract: A method of assembling a gas turbine assembly includes providing a core gas turbine engine including a high-pressure compressor, a combustor, and a turbine, coupling a low-pressure turbine to the core gas turbine engine, coupling a booster compressor to a gearbox, and coupling the gearbox to the low-pressure turbine such that the booster compressor is driven by the low-pressure turbine.

Abstract: This is related to a fan including a casing, a first impeller structure, a second impeller structure, and at least one driving device. The casing has an outlet and an air-containing portion having an entrance and an exit provided inside the casing. The first impeller structure and the second impeller structure are installed inside the casing, and include a first blade set and a second blade set, respectively. The first blade set is located corresponding to the entrance of the air-containing portion. The second blade set is located corresponding to the exit of the air-containing portion. The driving device drives the first and second impeller structures.

Abstract: A method and control for predicting the remaining useful life of an airfoil for a gas turbine engine includes the steps of monitoring conditions of the blade such as flutter, leaning, etc. A measured amount of deflection of the airfoil is compared to tabulated data to predict an expected crack length which is likely causing the deflection, etc. Once a predicted crack length has been identified, the amount of accumulated damage to the airfoil at the crack is monitored and stored. The amount of useful life for the blade can be predicted by compiling the accumulated damage over time. The useful life remaining can be displayed such that flight plans or maintenance schedules for the aircraft can be modified as appropriate.