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KR-20260062809-A - METHOD FOR REACTIVATING A COMBUSTION ENGINE IN STANDBY MODE DURING AN ASYMMETRIC OPERATING MODE IN A MULTI-ENGINE AIRCRAFT

KR20260062809AKR 20260062809 AKR20260062809 AKR 20260062809AKR-20260062809-A

Abstract

The present invention relates to a method for controlling a multi-engine aircraft (1) having an asymmetric operating mode, wherein at least one engine (10) is an active engine controlled by a control system (55) by outputting a non-zero effective driving force participating in the rotation of a rotor (5), and at least one engine (10) is a passive engine in standby mode. During the asymmetric operating mode, the present method comprises the following steps: ― A step of detecting the operation of the power unit (2) in a dangerous flight phase prior to the flight phase that is disadvantageous to the termination of the asymmetric operation mode using a control system (55); and ― A step of restarting the manual engine after detecting the operation of the power unit (2) during the dangerous flight phase.

Inventors

  • 세르케이라, 스테판

Assignees

  • 에어버스 헬리콥터스

Dates

Publication Date
20260507
Application Date
20250715
Priority Date
20241029

Claims (15)

  1. A method for controlling an aircraft (1) having a power unit (2) comprising at least two combustion engines (10), each having a power shaft (20) connected to a power transmission system (25), and a power transmission system (25) connected to at least one rotor (5). The above method comprises an asymmetric operating mode including using a control system (55) to control at least one active engine among at least two combustion engines (10) to an active speed, wherein the active engine outputs a non-zero active driving force that contributes to the rotation of the rotor (5) through its shaft (20) at the active speed, and the asymmetric operating mode includes switching at least one passive engine among at least two combustion engines (10) to a standby mode while controlling the active engine to an active speed, wherein the passive engine does not transmit power to the rotor (5). The above method, during an asymmetric operation mode, ― A step of detecting the operation of the power unit (2) in a dangerous flight phase prior to the flight phase that is disadvantageous to the termination of the asymmetric operation mode using a control system (55) (STPD); and ― After detecting the operation of the power unit (2) during the dangerous flight phase, the step of restarting the manual engine using the control system (55) (STPREAC) A method of controlling an aircraft (1) including
  2. In paragraph 1, A method for controlling an aircraft (1), wherein, after detecting the operation of the power unit (2) during a dangerous flight phase, the method includes a step (STPR1) of issuing an alarm using an alarm (80), and the control system (55) performs a step (STPREAC) of restarting the manual engine after operation by a human-machine control interface (88).
  3. In paragraph 1, A method for controlling an aircraft (1), characterized in that the above manual engine restart step (STPREAC) is automatically performed by a control system (55) after the step (STPD) of detecting the operation of the power unit (2) during a dangerous flight phase.
  4. In paragraph 1, A method for controlling an aircraft (1), wherein the above method includes the step (STPM01-STPM6) of measuring at least one monitoring parameter using individual sensors (40-47, 410, 440, 450, 460, 470) of a control system (55), and the step (STPD) of detecting operation of a power unit (2) during a dangerous flight phase includes the step (STPC0-STPC6) of detecting that the current value of the monitoring parameter is smaller than a relevant limit value.
  5. In paragraph 1, The above at least one monitoring parameter is the following parameter, — A temperature value function of the external temperature (T0) of the air surrounding the aircraft (1), wherein the external limit value (LTO) is measured using an external temperature sensor (40) and the relevant limit value is stored, and the step (STPD) for detecting operation of the power unit (2) during a dangerous flight phase includes the step (STPC0) of detecting that the temperature value is lower than the stored external temperature limit value; ― The oil temperature limit value (LTOIL) is measured using an oil temperature sensor (41) and has a stored relevant limit value, and the step (STPD) of detecting operation of the power unit (2) during a dangerous flight phase includes the step (STPC1) of detecting that the current value of the oil temperature (TOIL) is lower than the stored oil temperature limit value (LTOIL). The oil temperature (TOIL) of the lubrication circuit oil of the active engine; and ― Fuel temperature (TFUEL) of fuel supplied to an active engine, which is a fuel temperature limit value (LTFUEL) measured using a fuel temperature sensor (42) and has a stored related limit value, and a step (STPD) for detecting operation of the power unit (2) during a dangerous flight phase includes a step (STPC2) for detecting that the current value of the fuel temperature (TFUEL) is lower than the stored fuel temperature limit value (LTFUEL). A method of controlling an aircraft (1) characterized by including at least one of the following:
  6. In paragraph 5, A method for controlling an aircraft (1), characterized in that the above temperature value is equal to the external temperature (T0) or is calculated as a function of the current speed of the aircraft (1) measured using the external temperature (T0) and the speed sensor (43).
  7. In paragraph 4, A method for controlling an aircraft (1), wherein at least one monitoring parameter includes an ambient temperature (TCOMP) of an engine room (100) housing a manual engine, measured using an ambient temperature sensor (44), and an ambient temperature limit value (LTCOMP) in which a related limit value is stored, and a step (STPD) for detecting operation of a power unit (2) during a dangerous flight phase includes a step (STPC3) of detecting that the current value of the ambient temperature (TCOMP) is lower than the stored ambient temperature limit value (LTCOMP).
  8. In paragraph 4, A method for controlling an aircraft (1), characterized in that at least one monitoring parameter includes an internal temperature (LTENG) of a manual engine measured using an internal temperature sensor (45), an internal temperature limit value (LTENG) in which a related limit value is stored, and a step (STPD) for detecting operation of the power unit (2) during a dangerous flight phase includes a step (STPC4) for detecting that the current value of the internal temperature (LTENG) is lower than the stored internal temperature limit value (LTENG).
  9. In paragraph 4, A method for controlling an aircraft (1), wherein at least one monitoring parameter includes the oil pressure (POIL) of the lubrication circuit oil of a manual engine, the oil pressure is measured using an oil pressure sensor (46, 460), the relevant limit value is a stored oil pressure limit value (LPOIL), and the step of detecting operation of the power unit (2) during a dangerous flight phase (STPD) includes a step (STPC5) of detecting that the current value of the oil pressure (POIL) is less than the stored oil pressure limit value (LPOIL).
  10. In paragraph 4, A method for controlling an aircraft (1), wherein at least one monitoring parameter includes the fuel pressure (PFUEL) of fuel supplied to a manual engine, the relevant limit value is a stored fuel pressure limit value (LPFUEL), the fuel pressure (PFUEL) is measured using a fuel pressure sensor (47, 470), and the step of detecting operation of the power unit (2) during a dangerous flight phase (STPD) includes the step of detecting that the current value of the fuel pressure (PFUEL) is less than the stored fuel pressure limit value (LPFUEL) (STPC6).
  11. In paragraph 4, A method for controlling an aircraft (1), comprising the step of emitting a warning alarm (80) indicating an overactive phase of operation of the aircraft when at least one monitoring parameter is greater than or equal to a relevant limit value and less than or equal to a relevant threshold value, wherein the relevant threshold value is greater than the relevant limit value.
  12. In paragraph 1, A method for controlling an aircraft (1), wherein the step (STPD) of detecting the operation of the power unit (2) in a dangerous flight phase prior to a flight phase that is disadvantageous to termination in an asymmetric operation mode using the above control system (55) is characterized by operating independently of the operation of at least one active engine among at least two combustion engines (10).
  13. An aircraft (1) having a power unit (2) comprising at least two combustion engines (10) and a power transmission system (25) connected to at least one rotor (5), Each combustion engine (10) has a power shaft (20) connected to a power transmission system (25), The above aircraft has an asymmetric operating mode comprising using a control system (55) to control at least one active engine of at least two combustion engines (10) to an active speed, and The above active engine outputs a non-zero active driving force that contributes to the rotation of the rotor through the power shaft (20) at active speed, and The above asymmetric operating mode includes adjusting the active engine to an active speed while simultaneously switching at least one of the at least two combustion engines to a standby mode. The above manual engine does not transmit any power to the rotor (5), and The above control system (55) is an aircraft (1) configured to implement the method according to claim 1.
  14. In Paragraph 13, The above control system (55) is, An external temperature sensor (40) for measuring the external temperature (T0) of the air surrounding the aircraft (1); one oil temperature sensor (41, 410) per combustion engine (10) for measuring the oil temperature (TOIL) of the oil; a fuel temperature sensor (42) for measuring the fuel temperature (TFUEL) of the fuel supplied to each combustion engine (10); a speed sensor (43) for measuring the current speed of the aircraft (1); one ambient temperature sensor (44, 440) per combustion engine for measuring the ambient temperature (TCOMP) inside the engine room (100) housing the combustion engine (10); one internal temperature sensor (45, 450) per combustion engine (10) for measuring the internal temperature (LTENG) of the combustion engine (10); one oil pressure sensor (46, 460) per combustion engine (10) for measuring the oil pressure inside the combustion engine (10); An aircraft (1) characterized by including at least one of a fuel pressure sensor (47, 470) per combustion engine (10) for measuring the fuel pressure of fuel flowing into the combustion engine (10).
  15. In Paragraph 13, The above control system (55) is characterized by including an alarm (80), an aircraft.

Description

Method for Reactivating a Combustion Engine in Standby Mode During an Asymmetric Operating Mode in a Multi-Engine Aircraft Cross-reference of related applications This application claims priority to FR 24 11823 filed on October 29, 2024, the entire contents of which are incorporated herein by reference. The present invention relates to a method for reactivating a combustion engine in standby mode during asymmetric operation of a multi-engine aircraft. The aircraft may include a plurality of combustion engines for operating a mechanical system, for example, a mechanical system that rotates at least one rotor blade of a helicopter. The combustion engine may be in the form of a turboshaft engine equipped with a free turbine. A free turbine turboshaft engine comprises a compressor, a combustion chamber, and a gas generator equipped with a high-pressure expansion assembly constrained to rotate together with the compressor. The compressor may have one or more compression stages. Likewise, the expansion assembly may include one or more expansion turbines. Additionally, a free turbine turboshaft engine includes at least one low-pressure operating turbine, that is, a turbine mechanically independent of the rotation of the compressor and the high-pressure expansion assembly. The operating turbine rotates a power shaft connected to a driven mechanical system. According to another example, a combustion engine may include a piston engine. Accordingly, a rotary-wing aircraft may include a power unit having a plurality of combustion engines for driving a mechanical system, in particular a power transmission system that rotates at least one rotor. Optionally, the power unit can operate in a cooperative operation mode in which each combustion engine generates driving force to operate the mechanical system. The power unit may also operate in an asymmetrical operating mode by switching one of the engines to standby mode during a specific operating phase of the aircraft. In the case of a rotary-wing aircraft, in asymmetrical mode, at least one active engine is controlled to ensure rotation of the rotor by transmitting a non-zero active driving force to the rotor through the rotor's power shaft. However, at least one passive engine may be in standby mode. An engine in standby mode can be stopped by shutting down the combustion chamber. Fuel is no longer supplied to the combustion chamber of a manual engine, and in the case of a turboshaft engine, the rotating parts of the gas generator may or may not be operated by an electric machine. Alternatively, an engine in standby mode can be operated in idle or super-idle mode while igniting the combustion chamber to supply fuel. An engine in standby mode operates at a very low speed and does not transmit power to the rotor blades, with the active engine(s) supplying the full power. For example, a manual engine is in idle mode, and the rotational speed is about 40% of the rated rotational speed. Patent document EP 3209563 specifically describes an asymmetric operating mode. To exit asymmetrical operation mode, the manual engine must be restarted and controlled to increase output. However, restarting may be difficult under certain conditions. Patent document FR 3135965 proposes a method for heating a combustion engine in standby mode using hot air from an active combustion engine when the combustion engine in standby mode is exposed to freezing conditions. The present invention and its advantages are explained in more detail through the following description, which is provided exemplarily with reference to the attached drawings. FIG. 1 is a drawing of an aircraft according to the present invention. Figure 2 is a diagram illustrating the applied method. Elements appearing in two or more drawings each use the same reference numeral. FIG. 1 illustrates an example of an aircraft (1) according to the present invention. The aircraft (1) includes a rotor (5). The rotor (5) is equipped with a plurality of rotatable blades (5), which may be supported by a hub (7) or an equivalent part. For example, the rotor (5) forms a fixed or tilting propeller, a rotor blade, or a half-torque rotor. The aircraft (1) has a power unit (2) that rotates a rotor (5). This power unit (2) is equipped with at least two combustion engines (10). Reference numeral 10 indicates any combustion engine, and reference numerals 11 and 12 indicate specific engines if necessary. Each combustion engine (10) is housed in an engine room (100). Reference numeral 100 indicates any engine room, and reference numerals 101 and 102 indicate the engine rooms of combustion engines (11, 12), respectively. According to one example, at least one combustion engine (10) may be a turboshaft engine. Such a turboshaft engine (10) comprises at least one compression turbine (16), a combustion chamber (17) into which fuel is injected, and a gas generator (15) having at least one expansion turbine (18) limited to rotating together with at least one co