Abstract: A method of mitigating thermal rotor bow in a rotor assembly of a turbine engine may include performing a plurality of motoring cycles. The plurality of motoring cycles may include receiving feedback on a temperature within a turbine engine in a post-shutdown state, actuating a starter motor when the temperature is greater than a predetermined threshold, operating the starter motor for a motoring time to exhaust some residual heat from the turbine engine, and shutting down the starter motor after the motoring time.

Abstract: A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

Abstract: A method of operating a turbine engine that includes shutting down the turbine engine such that a rotational speed of the turbine engine decreases, and actuating a starter motor of the turbine engine at one of as the rotational speed of the turbine engine decreases or at a preset time after the turbine engine receives a full stop command such that residual heat is exhausted from the turbine engine.

Abstract: A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

Abstract: A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

Abstract: A gas turbine engine and method of starting, the gas turbine engine having a rotor comprising at least a shaft mounted compressor and turbine, with a casing surrounding the rotor. The method comprises an acceleration phase, a bowed-rotor cooling phase, during the acceleration, and a combustion phase. The bowed-rotor cooling phase comprises a time where the rotational speed of the rotor is maintained below a bowed-rotor threshold speed until a non-bowed condition is satisfied, wherein the air forced through the gas turbine engine cools the rotor. The combustion phase occurs after the bowed-rotor cooling phase and upon reaching the combustion speed, wherein fuel is supplied to the gas turbine engine is turned on.

Abstract: A method and system for fuel nozzle cleaning during engine operation is provided. The steps or operations include operating the compressor section to provide the flow of oxidizer to the combustion chamber, operating the fuel system at a first fuel flow condition, in which the first fuel flow condition provides a fuel-oxidizer ratio at the combustion chamber, operating the fuel system at a second fuel flow condition, in which the second fuel flow condition provides the fuel-oxidizer ratio at the combustion chamber equal at the first fuel flow condition and the second fuel flow condition, and operating the fuel system at a third fuel flow condition after operating the fuel system at the second fuel flow condition.

Abstract: A method of mitigating thermal rotor bow in a rotor assembly of a turbine engine may include performing a plurality of motoring cycles. The plurality of motoring cycles may include receiving feedback on a temperature within a turbine engine in a post-shutdown state, actuating a starter motor when the temperature is greater than a predetermined threshold, operating the starter motor for a motoring time to exhaust some residual heat from the turbine engine, and shutting down the starter motor after the motoring time.

Abstract: A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

Abstract: A method and system for fuel nozzle cleaning during engine operation is provided. The steps or operations include operating the compressor section to provide the flow of oxidizer to the combustion chamber, operating the fuel system at a first fuel flow condition, in which the first fuel flow condition provides a fuel-oxidizer ratio at the combustion chamber, operating the fuel system at a second fuel flow condition, in which the second fuel flow condition provides the fuel-oxidizer ratio at the combustion chamber equal at the first fuel flow condition and the second fuel flow condition, and operating the fuel system at a third fuel flow condition after operating the fuel system at the second fuel flow condition.

Abstract: A gas turbine engine and method of starting, the gas turbine engine having a rotor comprising at least a shaft mounted compressor and turbine, with a casing surrounding the rotor. The method comprises an acceleration phase, a bowed-rotor cooling phase, during the acceleration, and a combustion phase. The bowed-rotor cooling phase comprises a time where the rotational speed of the rotor is maintained below a bowed-rotor threshold speed until a non-bowed condition is satisfied, wherein the air forced through the gas turbine engine cools the rotor. The combustion phase occurs after the bowed-rotor cooling phase and upon reaching the combustion speed, wherein fuel is supplied to the gas turbine engine is turned on.

Abstract: A method of operating a turbine engine that includes actuating a starter motor of the turbine engine such that a motoring speed of the turbine engine increases, and actuating a plurality of variable stator vanes of the turbine engine such that the plurality of variable stator vanes are at least partially open to control the motoring speed of the turbine engine.

Abstract: A method of starting a gas turbine engine having a rotor comprising at least a shaft-mounted compressor and turbine, with a casing surrounding the rotor includes an acceleration phase, a bowed-rotor cooling phase, during the acceleration, and a combustion phase. The bowed-rotor cooling phase comprises a time where the rotational speed of the rotor is maintained below a bowed-rotor threshold speed until a non-bowed condition is satisfied, wherein the air forced through the gas turbine engine cools the rotor. The combustion phase occurs after the bowed-rotor cooling phase and upon reaching the combustion speed, wherein fuel is supplied to the gas turbine engine.

Abstract: A start-up system including a control system controlling a partial opening of an air intake valve of a start-up turbine during a first phase of the start-up. The start-up turbine is capable of turning a rotor of the turbomachine for the purpose of the start-up, so as to prevent the rotor from encountering critical frequencies of the turbomachine.

Abstract: A method of operating a turbine engine that includes shutting down the turbine engine such that a rotational speed of the turbine engine decreases, and actuating a starter motor of the turbine engine at one of as the rotational speed of the turbine engine decreases or at a preset time after the turbine engine receives a full stop command such that residual heat is exhausted from the turbine engine.

Abstract: A method of operating a turbine engine that includes actuating a starter motor of the turbine engine such that a motoring speed of the turbine engine increases, and actuating a plurality of variable stator vanes of the turbine engine such that the plurality of variable stator vanes are at least partially open to control the motoring speed of the turbine engine.