United Technologies Corporation

Rtx Corporation

Hamilton Sundstrand Corporation

Raytheon Technologies Corporation

Jason B Solomonides

John P Virtue

Marc J Muldoon

Jorn Axel Glahn

Matthew R Feulner

Matthew D Teicholz

Bradley C Schafer

Brian V Winebrenner

William H Greene, Jr

Jeffrey W Sutliff

Victor M Pinedo

Philip D Hoover

Kenneth J White

Gregory I Rozman

Jacek F Gieras

Allan J Volponi

Jesse W Clauson

Joshua Adams

David Gelwan

Timothy J Gaudet

Ronald P Bauer

A bowed rotor prevention system includes a gas turbine engine, and electric motor, and a core turning controller. The gas turbine engine includes a rotor that is rotatably coupled to a drive shaft. The electric motor is rotatably coupled to a motor shaft, which is mechanically coupled to the drive shaft so as to rotate therewith. The core turning controller in signal communication with the electric motor. The core turning controller determines whether a rotor bow is present in the rotor based on an operating time of the gas turbine engine, determines a motoring time based on the operating time, and invokes an anti-rotor bowing mode configured to control the electric motor to rotate the rotor according to the motor time.

Core turning system

A bowed rotor prevention system includes a gas turbine engine, an electric motor, and a core turning controller in signal communication with the electric motor. The gas turbine engine includes a rotor that is rotatably coupled to a drive shaft. The electric motor rotatably is coupled to a motor shaft, which is mechanically coupled to the drive shaft so as to rotate therewith. The core turning controller is configured to invoke an anti-rotor bowing mode, and to control the electric motor to periodically rotate the rotor into a plurality of rotor positions during a given time period in response to invoking the anti-rotor bowing mode.

Optimized bowed rotor control method

A system for starting a gas turbine engine of an aircraft is provided. The system includes a pneumatic starter motor, a discrete starter valve switchable between an on-state and an off-state, and a controller operable to perform a starting sequence for the gas turbine engine. The starting sequence includes alternating on and off commands to an electromechanical device coupled to the discrete starter valve to achieve a partially open position of the discrete starter valve to control a flow from a starter air supply to the pneumatic starter motor to drive rotation of a starting spool of the gas turbine engine below an engine idle speed, where the controller modulates a duty cycle of the discrete starter valve via pulse width modulation.

Modified start sequence of a gas turbine engine

A system for controlling a start sequence of a gas turbine engine includes an electronic engine control system, a thermal model, memory, a model for determining a time period (t), and a controller. The thermal model synthesizes a heat state of the gas turbine engine. The memory records the current heat state at shutdown and a shutdown time of the gas turbine engine. The model for determining the time period is for motoring the gas turbine engine at a predetermined speed Nthat is less than a speed to start the gas turbine engine, where tis a function of the heat state recorded at engine shutdown and an elapsed time of an engine start request relative to a previous shutdown time. The controller modulates a starter valve to maintain the gas turbine engine within a predetermined speed range of Nto Nfor homogenizing engine temperatures.

A system is provided for speed control during motoring of a gas turbine engine of an aircraft. The system includes an air turbine starter, a starter air valve operable to deliver compressed air to the air turbine starter, and a controller. The controller is operable to adjust the starter air valve to control motoring of the gas turbine engine based on measured feedback with lead compensation to reject disturbances attributable to dual to single or single to dual engine starting transitions.

Speed control during motoring of a gas turbine engine

A system for starting a gas turbine engine of an aircraft is provided. The system includes a pneumatic starter motor, a discrete starter valve switchable between an on-state and an off-state, and a controller operable to perform a starting sequence for the gas turbine engine. The starting sequence includes alternating on and off commands to an electromechanical device coupled to the discrete starter valve to achieve a partially open position of the discrete starter valve to control a flow from a starter air supply to the pneumatic starter motor to drive rotation of a starting spool of the gas turbine engine below an engine idle speed.

A more-electric engine (MEE) system configured to operate in a plurality of operating modes includes a first power generating sub-system and a second power generating sub-system. The first power generating sub-system is configured to output electric power to a first power bus. The second power generating sub-system is configured to output electric power to a second power bus. The MEE system further includes an electronic source/load management and distribution (SLMD) module in power and signal communication with each of the first power generating sub-system, the second power generating sub-system, and the plurality of electrical sub-systems. The electronic SLMD module is configured to selectively operate the MEE system in one of a first operating mode or a second operating mode among the plurality of operating modes. The first and second operating modes adjust the delivery of the first and second electric power to the first and second power buses.

Electric system architecture included in a more-electric engine (MEE) system

A control system comprises an active dead band, coupled to a feedback path of the control system, configured to receive a first signal derived from a motor position signal of the feedback path of the control system and a utilize, in accordance with the signal, a set of thresholds to prevent feedback noise within a driveline of the control system.

Active dead band for noise reduction in high response high bandwidth control systems

Three separate fuzzy rule sets are applied to three corresponding fuzzy sets developed from various input parameters for providing a pitch engagement/mode selection management system and method for requesting disablement of a blade lock, for disabling such lock when the torque available matches the torque required, and for selecting a motor or brake for creating a differential speed between a rotating pitch change mechanism and a fan shaft of a turbine engine. A fuzzeresis rule set is disclosed for stabilizing the motor/brake mode selection fuzzy logic output.

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Cromwell, CT, United States of America

Jason B Solomonides