Abstract: A method and system for correlating engine thrust and engine thrust lever angle (TLA) during operation of a gas turbine engine powered aircraft is provided. The method includes: a) providing current flight conditions including a Mach number of the aircraft, altitude of the aircraft, and a TLA; b) determining a corrected fan speed value based on a sensed fan speed and flight conditions; c) determining a first corrected net thrust value based on the corrected fan speed value and the Mach number; d) determining a compensation factor using the corrected fan speed value, the Mach number, and the corrected net thrust value; e) determining a second corrected net thrust value as a function of the TLA; and f) correlating an engine fan speed to the TLA using the second corrected net thrust value as a function of the TLA and the compensation factor.

Abstract: A system for determining an indicated turbine temperature (ITT) for a gas turbine engine includes an engine control system. The engine control system includes a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to: determine a first estimated outlet temperature value for a high-pressure turbine of the gas turbine engine, determine an estimated work ({dot over (W)}HPT) of the high-pressure turbine, determine an estimated inlet temperature value for the high-pressure turbine using the estimated work ({dot over (W)}HPT), and determine the ITT by calculating a second estimated outlet temperature value using the estimated inlet temperature value, the second estimated outlet temperature value different than the first estimated outlet temperature value.

Abstract: Methods and systems for operating an engine, the engine having an engine core, an exhaust nozzle, and variable geometry mechanisms, are provided. A request for an increase in thrust generated by the engine is received. In response to receipt of the request, it is determined that at least one operating condition for engine degradation thrust is met. In response to this determination, the variable geometry mechanisms are modulated to degrade an efficiency of the engine, thereby increasing a temperature of core air flowing through the engine core. The increase in thrust is generated from the increased temperature of the core air flowing through the engine core and into the exhaust nozzle.

Abstract: There is provided a system and a method for controlling a tip clearance between a turbine casing and turbine blade tips of an aircraft engine. At least one operational parameter of the aircraft engine is obtained. Based on the at least one operational parameter, a current value of the tip clearance and a target value of the tip clearance are determined. A limiting factor to be applied to the target value of the tip clearance is computed. The limiting factor is applied to the target value of the tip clearance to obtain a tip clearance demand for the aircraft engine. A tip clearance control apparatus of the aircraft engine is controlled based on a difference between the current value of the tip clearance and the tip clearance demand.

Abstract: Methods and systems for operating an engine, the engine having an engine core, an exhaust nozzle, and variable geometry mechanisms, are provided. A request for an increase in thrust generated by the engine is received. In response to receipt of the request, it is determined that at least one operating condition for engine degradation thrust is met. In response to this determination, the variable geometry mechanisms are modulated to degrade an efficiency of the engine, thereby increasing a temperature of core air flowing through the engine core. The increase in thrust is generated from the increased temperature of the core air flowing through the engine core and into the exhaust nozzle.

Abstract: There is provided a system and a method for controlling a tip clearance between a turbine casing and turbine blade tips of an aircraft engine. At least one operational parameter of the aircraft engine is obtained. Based on the at least one operational parameter, a current value of the tip clearance and a target value of the tip clearance are determined. A limiting factor to be applied to the target value of the tip clearance is computed. The limiting factor is applied to the target value of the tip clearance to obtain a tip clearance demand for the aircraft engine. A tip clearance control apparatus of the aircraft engine is controlled based on a difference between the current value of the tip clearance and the tip clearance demand.

Abstract: Fuel control systems for use with a gas turbine engines which accounts for real-time thermodynamic engine effects when attempting to match or track the NDOTActual rate to the NDOTDemand rate. The fuel control system includes a mechanism for measuring several engine operating parameters and a mechanism for determining an initial engine fuel demand based on the measured engine operating parameters. The control system further includes a mechanism for estimating, during engine operation and based on the measured operating parameters, the amount of heat transferred between fuel combustion gases and the engine metal and estimating an effective fuel flow adjustment based therefrom. The control system disclosed herein also includes a mechanism for determining a final engine fuel demand based on the initial predicted engine fuel demand and the estimated effective fuel flow adjustment.

Abstract: An adaptive aero-thermodynamic engine model is disclosed which incorporates a plurality of model engine operating parameters, a plurality of nominal component efficiencies and corresponding efficiency modifier functions. The engine model is adapted by measuring a plurality of engine operating parameters corresponding to the plurality of model engine operating parameters during steady state operation of the engine over a plurality of data points, matching each of the model engine operating parameters to respective measured engine operating parameters by iteratively adapting each of the nominal component efficiencies using the corresponding efficiency modifier functions, estimating actual component efficiencies based upon the adapted nominal component efficiencies, and inputting the estimated actual component efficiencies into the engine model.

Abstract: Fuel control systems for use with a gas turbine engines which accounts for real-time thermodynamic engine effects when attempting to match or track the NDOTActual rate to the NDOTDemand rate. The fuel control system includes a mechanism for measuring several engine operating parameters and a mechanism for determining an initial engine fuel demand based on the measured engine operating parameters. The control system further includes a mechanism for estimating, during engine operation and based on the measured operating parameters, the amount of heat transferred between fuel combustion gases and the engine metal and estimating an effective fuel flow adjustment based therefrom. The control system disclosed herein also includes a mechanism for determining a final engine fuel demand based on the initial predicted engine fuel demand and the estimated effective fuel flow adjustment.

Abstract: Fuel control systems for use with a gas turbine engines which accounts for real-time thermodynamic engine effects when attempting to match or track the NDOTActual rate to the NDOTDemand rate. The fuel control system includes a mechanism for measuring several engine operating parameters and a mechanism for determining an initial engine fuel demand based on the measured engine operating parameters. The control system further includes a mechanism for estimating, during engine operation and based on the measured operating parameters, the amount of heat transferred between fuel combustion gases and the engine metal and estimating an effective fuel flow adjustment based therefrom. The control system disclosed herein also includes a mechanism for determining a final engine fuel demand based on the initial predicted engine fuel demand and the estimated effective fuel flow adjustment.

Abstract: Fuel control systems for use with a gas turbine engines which accounts for real-time thermodynamic engine effects when attempting to match or track the NDOTActual rate to the NDOTDemand rate. The fuel control system includes a mechanism for measuring several engine operating parameters and a mechanism for determining an initial engine fuel demand based on the measured engine operating parameters. The control system further includes a mechanism for estimating, during engine operation and based on the measured operating parameters, the amount of heat transferred between fuel combustion gases and the engine metal and estimating an effective fuel flow adjustment based therefrom. The control system disclosed herein also includes a mechanism for determining a final engine fuel demand based on the initial predicted engine fuel demand and the estimated effective fuel flow adjustment.

Abstract: An adaptive aero-thermodynamic engine model is disclosed which incorporates a plurality of model engine operating parameters, a plurality of nominal component efficiencies and corresponding efficiency modifier functions. The engine model is adapted by measuring a plurality of engine operating parameters corresponding to the plurality of model engine operating parameters during steady state operation of the engine over a plurality of data points, matching each of the model engine operating parameters to respective measured engine operating parameters by iteratively adapting each of the nominal component efficiencies using the corresponding efficiency modifier functions, estimating actual component efficiencies based upon the adapted nominal component efficiencies, and inputting the estimated actual component efficiencies into the engine model.