Abstract: A method of detecting rubs during operation of a turbomachine comprising at least one rotating object having a tip and a shelf is provided. The method includes generating signals representative of a sensed parameter and processing the signals to generate height versus time data for the tip. The height of the tip corresponds to the distance between the tip and the shelf. The method further includes monitoring the height versus time data, in order to determine whether a change in the height data exceeds a threshold value, and detecting a rub of the rotating object(s) on a second object, when the change in the height data exceeds the threshold value. A rub detection system for a turbomachine and a turbine engine system with rub detection are also provided.

Abstract: A method and system adjusts blade tip clearance between rotating aircraft gas turbine engine blade tips and a surrounding shroud in anticipation of and before an engine command that changes an engine rotational speed. The method may include determining when to begin adjusting the tip clearance by expanding or contracting the shroud before the engine command and may be based on monitored aircraft and/or aircraft crew data indicative of the engine. The aircraft and/or aircraft crew data may include communications between aircraft crew and air traffic control authorities or air traffic control surrogates. Determining when to begin adjusting the tip clearance may include using learning algorithms which may use the aircraft gas turbine engine's operating experience and/or operating experience of other jet engines on an aircraft containing the aircraft gas turbine engine and/or on other aircraft.

Abstract: A processing system for clearance estimation in a rotating machine includes one or more sensors and one or more digital signal processors for calculating the estimated clearance. The processing system may include techniques for obtaining real-time clearance estimates and techniques for obtaining averaged clearance estimates. Aspects of the processing system may also include a method of switching between real-time clearance estimates and averaged clearance estimates depending on the operating conditions of the rotating machine. Other aspects of the processing system include the use of two digital signal processors: a first digital signal processor configured to receive signals from a clearance sensor and perform a first set of high speed processing tasks, and a second digital signal processor configured to receive signals from the first digital signal processor and perform a second set of lower speed processing tasks.

Abstract: A sensor system for measuring a clearance parameter between a stationary component and a rotating component of a rotating machine is provided. The system includes a clearance sensor to output a clearance measurement signal. A sensor memory is attached to the sensor for storing a first sensor information. A second sensor information is stored in a electronics interface memory. The first and the second sensor information are read and the clearance sensor is matched with a respective plurality of calibration data by an electronic interface based on the first and the second sensor information.

Abstract: A seal assembly comprising a first movable stator member movable between a sealing position and a non-sealing position, a second fixed stator member, the first stator member being movable relative to the second stator member, the seal assembly further comprising at least one flexure member coupled to the second stator member, and at least one biasing member coupled between the at least one flexure and the movable stator for biasing the movable stator to a non-sealing position.

Abstract: A sensor system for measuring a clearance parameter between a stationary component and a rotating component of a rotating machine is provided. The system includes a clearance sensor to output a clearance measurement signal. A sensor memory is attached to the sensor for storing a first sensor information. A second sensor information is stored in a electronics interface memory. The first and the second sensor information are read and the clearance sensor is matched with a respective plurality of calibration data by an electronic interface based on the first and the second sensor information.

Abstract: A multi sensor clearance probe with at least longitudinally and transversely spaced apart first and second sensors operable to measure first and second distances respectively between the sensors and a longitudinally spaced apart rotating rotor. The sensors being operable to measure blade tip clearances between radially outer turbine blade tips and an annular stator shroud circumscribing the blade tips. The blade tips may be squealer tips and the sensors operable to measure the distances between the sensors and tops of squealer tip walls and outwardly facing walls within cavities of the squealer tips. The probe may be operably connected to a controller for sending signals to the controller indicating the first and second distances for controlling an air valve used for active clearance control. Two or more of the probe may be used to determine rotor centerline offset.

Abstract: A sensor system for measuring a clearance parameter between a stationary component and a rotating component of a rotating machine is provided. The system includes a clearance sensor to output a clearance measurement signal. A sensor memory is attached to the sensor for storing a first sensor information. A second sensor information is stored in a electronics interface memory. The first and the second sensor information are read and the clearance sensor is matched with a respective plurality of calibration data by an electronic interface based on the first and the second sensor information.

Abstract: A processing system for clearance estimation in a rotating machine includes one or more sensors and one or more digital signal processors for calculating the estimated clearance. The processing system may include techniques for obtaining real-time clearance estimates and techniques for obtaining averaged clearance estimates. Aspects of the processing system may also include a method of switching between real-time clearance estimates and averaged clearance estimates depending on the operating conditions of the rotating machine. Other aspects of the processing system include the use of two digital signal processors: a first digital signal processor configured to receive signals from a clearance sensor and perform a first set of high speed processing tasks, and a second digital signal processor configured to receive signals from the first digital signal processor and perform a second set of lower speed processing tasks.

Abstract: A row of turbine blades is surrounded by a turbine shroud. The shroud is supported by a turbine case having a pair of radially outwardly extending rails. The rails are perforate for channeling therethrough control air to control thermal radial movement of the case, and in turn radial position of the shroud supported therefrom.

Abstract: A system for measuring clearance between a stationary object and a movable object is provided. The system includes at least one sensor configured to be disposed on the stationary object and configured to measure an operating parameter corresponding to the movable object and a controller coupled to the at least one sensor, wherein the controller is configured to control an operating mode of the sensor based upon the measured operating parameter.

Abstract: A method for estimating a trend in exhaust gas temperature in a turbine engine includes sampling exhaust gas temperature and a plurality of variables associated with the exhaust gas temperature over a set of observation times for a turbine engine to acquire exhaust gas temperature data. A trend in the exhaust gas temperature for the specific turbine engine is identified by removing the effect of the plurality of variables on the exhaust gas temperature data.

Abstract: A multi sensor clearance probe with at least longitudinally and transversely spaced apart first and second sensors operable to measure first and second distances respectively between the sensors and a longitudinally spaced apart rotating rotor. The sensors being operable to measure blade tip clearances between radially outer turbine blade tips and an annular stator shroud circumscribing the blade tips. The blade tips may be squealer tips and the sensors operable to measure the distances between the sensors and tops of squealer tip walls and outwardly facing walls within cavities of the squealer tips. The probe may be operably connected to a controller for sending signals to the controller indicating the first and second distances for controlling an air valve used for active clearance control. Two or more of the probe may be used to determine rotor centerline offset.

Abstract: A method and system adjusts blade tip clearance between rotating aircraft gas turbine engine blade tips and a surrounding shroud in anticipation of and before an engine command that changes an engine rotational speed. The method may include determining when to begin adjusting the tip clearance by expanding or contracting the shroud before the engine command and may be based on monitored aircraft and/or aircraft crew data indicative of the engine. The aircraft and/or aircraft crew data may include communications between aircraft crew and air traffic control authorities or air traffic control surrogates. Determining when to begin adjusting the tip clearance may include using learning algorithms which may use the aircraft gas turbine engine's operating experience and/or operating experience of other jet engines on an aircraft containing the aircraft gas turbine engine and/or on other aircraft.

Abstract: A method of detecting rubs during operation of a turbomachine comprising at least one rotating object having a tip and a shelf is provided. The method includes generating signals representative of a sensed parameter and processing the signals to generate height versus time data for the tip. The height of the tip corresponds to the distance between the tip and the shelf. The method further includes monitoring the height versus time data, in order to determine whether a change in the height data exceeds a threshold value, and detecting a rub of the rotating object(s) on a second object, when the change in the height data exceeds the threshold value. A rub detection system for a turbomachine and a turbine engine system with rub detection are also provided.

Abstract: A method to compensate for blade tip clearance deterioration between rotating blade tips and a surrounding shroud in an aircraft gas turbine engine includes determining one or more variables based on at least one or more moving averages of one or more engine operating parameters respectively averaged over a fixed number of operational engine flight cycles and adjusting a flow rate of thermal control air to counter the blade tip clearance deterioration based on the one or more variables. The engine operating parameters may include running number of engine cycles, takeoff and cruise exhaust gas temperature margins, a cruise turbine efficiency, takeoff and cruise maximum turbine speeds, a cruise fuel flow. Some or all of the variables may be differences between the moving averages and corresponding baselines of the engine operating parameters respectively or the variables may all be moving averages. The flow rate may be adjusted incrementally.

Abstract: A row of turbine blades is surrounded by a turbine shroud. The shroud is supported by a turbine case having a pair of radially outwardly extending rails. The rails are perforate for channeling therethrough control air to control thermal radial movement of the case, and in turn radial position of the shroud supported therefrom.

Abstract: A method to compensate for blade tip clearance deterioration between rotating blade tips and a surrounding shroud in an aircraft gas turbine engine includes determining one or more variables based on at least one or more moving averages of one or more engine operating parameters respectively averaged over a fixed number of operational engine flight cycles and adjusting a flow rate of thermal control air to counter the blade tip clearance deterioration based on the one or more variables. The engine operating parameters may include running number of engine cycles, takeoff and cruise exhaust gas temperature margins, a cruise turbine efficiency, takeoff and cruise maximum turbine speeds, a cruise fuel flow. Some or all of the variables may be differences between the moving averages and corresponding baselines of the engine operating parameters respectively or the variables may all be moving averages. The flow rate may be adjusted incrementally.

Abstract: An annular blade retention plate for axially retaining rotor blades within slots of a rotor disk. The plate includes an annular plate web extending radially outwardly from a radially inner plate hub to a plate rim and an annular radially outwardly open outer channel in a radially outwardly facing outer surface of the rim. A sealing ring is received within the outer channel and the sealing ring has axial rectangularly shaped cross-sections. An annular axially forwardly open inner channel in an annular ridge on a forward plate face of the plate web has an annular seal wire received therein. In a rotor assembly having a rotor disk supporting a plurality of circumferentially spaced apart rotor blades mounted in corresponding axially extending slots and the plate mounted to the rotor disk the sealing ring is in sealing engagement with radially inwardly facing surfaces of blade platforms of the blades.

Abstract: A seal assembly for installation between rotating and stationary components of a machine includes a first plurality of leaf spring segments secured to the stationary component in a circumferential array surrounding the rotating component, the leaf spring segments each having a radial mounting portion and a substantially axial sealing portion, the plurality of leaf spring segments shingled in a circumferential direction.