Method and system for engine windmilling control
AssigneePratt & Whitney Canada Corp.
InventorsKashif Mohammed, Patrick Manoukian, Patrice Remy
Life of this patent
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Abstract
Methods and systems for controlling windmilling in an engine are described. An electric starter motor is coupled to the engine, a circuit element is coupled to the electric starter engine and to a DC signal source, and a control system coupled to the engine and to the circuit element. The control system is configured for: determining whether the engine is in a windmilling state; when the engine is in a windmilling state, commanding the circuit element to apply a DC signal to the electric starter motor; and modulating the DC signal applied to the electric starter motor to control a level of rotational motion of the engine.
Claims20
A method for controlling windmilling of an engine of an aircraft during flight, the engine being an auxiliary power unit of the aircraft, the method comprising:
- charging a direct current (DC) source during operation of the engine;
- during flight of the aircraft, determining that the engine is windmilling and that a fire event is occurring in a vicinity of the engine;
- when the engine is determined to be windmilling, rotational motion of a rotatable component of the engine is caused by the windmilling and the fire event is occurring, controlling the rotational motion of the rotatable component of the engine by:
- commanding a circuit element to apply a DC signal from the DC source to an electric starter motor coupled to the rotatable component of the engine;
- and
- modulating the DC signal applied to the electric starter motor to reduce the rotational motion of the rotatable component of the engine.
An aircraft system comprising:
- an auxiliary power unit (APU) for supplying electricity and compressed air;
- a direct current (DC) signal source chargeable during operation of the APU;
- an electric starter motor coupled to a rotatable component of the APU;
- a circuit element coupled to the electric starter motor and a DC signal source;
- and
- a control system coupled to the APU and to the circuit element, and configured for:
- determining whether the APU is windmilling by determining that an inlet duct to the APU is in an open position when the APU is in an off state;
- detecting that a fire event is occurring in a vicinity of the engine;
- during flight of the aircraft, when the APU is in the off state, and when rotational motion of the rotatable component of the APU is caused by the windmilling and the fire event is occurring, controlling the rotational motion of the rotatable component of the APU by:
- commanding a circuit element to apply a DC signal from the DC signal source to the electric starter motor coupled to the rotatable component of the APU;
- and
- modulating the DC signal applied to the electric starter motor to reduce the rotational motion of the rotatable component of the APU.
Dependencies are inferred from the claim text.