FR3141679A1 - Assembly comprising an aircraft and an infrastructure as well as a method of taking off the aircraft from the infrastructure - Google Patents

Abstract

Assembly comprising an aircraft (2) equipped with an autonomous propulsion system comprising at least one thruster actuated by an electric motor (201) and an infrastructure comprising a track (10), the propulsion system and the track being configured to allow the take-off of the aircraft, characterized in that the infrastructure comprises a first device (213), an energy transmitter, in that the aircraft (2) carries a second device (209), configured to capture the energy of the first device (213) and transform it into energy usable by the electric motor (201) of said at least one propeller, the first (213) and second (209) devices being configured to transmit the energy to each other when the aircraft (2) is on at least part of the track (10). The invention also relates to the aircraft and the take-off method. Figure for abstract: [Fig 2]

Description

Assembly comprising an aircraft and an infrastructure as well as a method of taking off the aircraft from the infrastructure

The present invention relates in particular to the field of aircraft, in particular civil aircraft. It relates more particularly to means for taking off an aircraft from an infrastructure, in particular an airport on the ground.

State of the art

Civil aviation in particular is facing the ecological challenge of carbon dioxide production, as well as environmental nuisances such as noise. Faced with these challenges, manufacturers are beginning to develop concepts for electrically powered aircraft.

A schematic example of the architecture of such an aircraft can be found in document WO2012171520-A1. With reference to the , the propulsion system of such an aircraft 1 comprises at least one thruster composed here of an electric motor 101 actuating the blades of a propeller 102. It also comprises an on-board electrical energy source 103, here a lithium-air battery, and a conduction means 104 intended to transfer the electrical energy from the battery 103 to the electric motor 101. It also comprises a control means, not shown in the figure, for controlling the electric motor 101. Furthermore, although this is not shown, the fuselage 105 of such an aircraft may comprise a cabin intended to accommodate passengers, for commercial applications in particular.

The aircraft 1 shown is designed to fly under the effect of the thrust of the propeller thanks to the lift of its wings 106. The power of the engine 101 of the propulsion system is defined so as to allow the takeoff of the aircraft on an airport runway (from a few hundred meters to 3000 meters depending on the size of the aircraft), in cooperation with a lift augmentation system formed here of flaps 107 which can be deflected, and to give it a given cruising speed.

One of the biggest problems with electric propulsion for aircraft is energy storage, which weighs on their mass balance.

Several solutions are possible to reduce the need for energy and therefore energy storage, such as a reduction in speed or higher lift. The fact remains that the take-off phase, with the acceleration of the aircraft to reach its take-off speed, is a source of very significant energy consumption. Particularly with electric propulsion, the storage of this energy to be consumed from the start represents a mass that is detrimental to the aircraft's performance.

The object of the present invention is to propose a solution for reducing the need for energy storage of the aircraft, in particular with electric propulsion, and therefore to improve its mass balance.

For this purpose, the invention relates to an assembly comprising an aircraft equipped with an autonomous propulsion system comprising at least one thruster actuated by an electric motor and an infrastructure comprising a runway, the propulsion system and the runway being configured to allow the aircraft to take off, characterized in that the infrastructure comprises a first device, emitting energy, in that the aircraft carries a second device, configured to capture the energy of the first device and transform it into energy usable by the electric motor of said at least one thruster, the first and second devices being configured to transmit the energy to each other when the aircraft is on at least part of the runway.

The propulsion system is autonomous, so it includes an energy source capable of operating the electric motor of the propeller. However, in this way, the infrastructure, such as an airport, can provide the aircraft with the energy necessary for its takeoff without the latter using its on-board energy source. This saves the corresponding mass in the aircraft's balance sheet, which allows its range or transport capacity to be increased.

Preferably, the electric motor of said at least one propeller having a given energy consumption to ensure the takeoff of the aircraft, the infrastructure comprises an energy source configured to provide an energy flow corresponding to said given energy consumption to the first device, the first and the second device being sized to pass this energy flow.

According to different embodiments, said first and second devices comprise components cooperating by contact, by induction, or by transmission of directed waves to transmit the energy intended for the electric motor of said at least one thruster.

In particular, induction transmission has the advantage of minimizing friction and physical interactions with the aircraft rolling on the runway.

Advantageously, the first device comprises a component intended to cooperate with the second device for the transfer of energy which is installed at the edge of the track or under a track covering.

For example, if the energy transmission is done by contact, by sliding a catenary on a rail, the installation of the rail at the edge of the runway, outside the rolling zone of the aircraft's undercarriages, avoids interactions with them. Similarly, for example, an induction cable buried under the runway makes it possible to maintain the integrity of the rolling zone for the aircraft's undercarriages.

The invention also relates to an aircraft equipped with an autonomous propulsion system comprising at least one thruster actuated by an electric motor, remarkable in that it comprises a said second device, configured so as, on the one hand, to cooperate with a said first energy-emitting device of an infrastructure, said infrastructure comprising a runway intended to be traveled by the aircraft for its takeoff, to capture energy emitted by the latter, and on the other hand, to transform said energy to make it usable by the electric motor of said at least one thruster.

Advantageously, the propulsion system comprising an on-board electrical energy source designed to transmit a given maximum power to the electric motor of said at least one thruster, the latter and said second device are designed to absorb a power greater than said maximum power, said at least one thruster comprising thrust increase means configured in particular for aircraft speeds less than or equal to a given take-off speed.

The engine will thus be able to exert a stronger thrust during take-off and one can take advantage of a possible existing power source in the infrastructure much higher than what could be installed in the aircraft, for example to minimize take-off distances and reduce the size of runways.

The invention also relates to an infrastructure comprising a runway intended to be traveled by aircraft for their take-off, remarkable in that it comprises a said first device comprising a component installed at the edge of the runway or in the runway intended to transfer electrical energy by contact, by induction or by directed wave to a said second capture device on an aircraft, as well as an energy source configured to power said first device.

The invention also relates to a method for taking off an aircraft from an infrastructure, the assembly being defined as previously, comprising a step of traveling along the runway by said aircraft, characterized in that the infrastructure transmits to the electric motor of said at least one propeller of the aircraft at least part of the energy it needs to take off the aircraft.

In this way, the aircraft does not have to store this energy transmitted by the infrastructure and its mass balance can be saved. This process does not involve any fundamental transformation in the design of the aircraft.

The aircraft propulsion system comprising an on-board energy source designed to transmit a maximum given power, the method may comprise a step of traveling the runway during which the electric motor of said at least one propeller operates at a power greater than said given maximum power, so as to give a catapult effect by the thrust of said at least one propeller.

In this way, it is possible to increase the speed of the aircraft during take-off and therefore reduce the on-board energy required, or to minimise the size of the suitable take-off runways.

The method may also include a step during which, the aircraft having taken off from the runway, the infrastructure still transmits energy to the electric motor of said at least one propeller.

This is the case, for example, if the energy is transmitted by the infrastructure to the aircraft during the entire runway phase, since during part of the climb phase in the runway axis, energy is still transmitted to it by directed energy means or by a cord. This saves even more energy to be loaded into the aircraft.

Brief description of the figures

The present invention will be better understood and other details, characteristics and advantages of the present invention will appear more clearly on reading the description of a non-limiting example which follows, with reference to the appended drawings in which:

presents a schematic perspective view of an electric aircraft according to the state of the art;

presents a schematic perspective view of an electric aircraft on a take-off runway according to a first embodiment of the invention; and

shows a schematic perspective view of an electric aircraft on a take-off runway according to a second embodiment of the invention.

Detailed description

In reference to the , in an embodiment based on the state of the art described above, the aircraft 2 comprises an electric propulsion system with an electric motor 201 driving the blades of a propeller 202, powered by batteries 203 via an electrical network 204, the whole being here installed in the fuselage 205. As in the state of the art, the aircraft 2 is designed to fly under the effect of the thrust of the propeller, comprising the engine 201 and the propeller blades 202, thanks to the lift of its wings 206. The power of the engine 201 of the propeller is defined so as to allow the takeoff of the aircraft on an airport runway, in cooperation with a lift augmentation system formed here of flaps 207 which can be deflected, and to give it a given cruising speed. A control means 208, for example an on-board computer, controls the electrical power supply of the motor 201 to adapt its speed to the different flight phases.

According to the invention, the aircraft 2 comprises an electrical energy capture device 209 connected to the electrical network 204 supplying the engine 201 of the propulsion system. In the example, the capture device 209 comprises a pantograph 210 fixed under the wing 206 and carrying at its free end an electrical contact pad 211 connected to the electricity conduction means 204 by a switch 212. The switch 212 is connected to the control means 208 to manage the transfers of electricity supply to the engine 201 by the battery 203 and via the electricity capture means 209.

The contact pad 211 is configured to slide by rubbing on an electric rail 213 arranged longitudinally on the part of a runway 10 traveled by the aircraft 2 during its takeoff phase, so as to pass the electrical power consumed by the motor 201 from the rail 213 to the contact pad 211.

Preferably, the contact pad 211 has an elongated shape transversely to the longitudinal axis of the aircraft 2. The transverse extension of the contact pad 211 makes it possible to maintain contact between the pad 211 and the rail 213 even if the aircraft 2 is not exactly positioned transversely on the runway 10.

Also preferably, the contact pad 211 is formed of a conductive material that is less hard than the material of the rail 213. Thus, the contact pad 211 will wear preferentially over the rail 213. From an economic and safety perspective, it is preferable to change pads on airplanes than rails on runways.

The pantograph 210 is configured to maintain sliding electrical contact between the contact pad 211 and the rail 213 on the runway 10 while the aircraft 2 travels along the runway 10 to take off by rolling by means of a set of undercarriages 214, absorbing variations in vertical deviation between the aircraft and the runway. Advantageously, the pantograph 211 may have sufficient extension, for example with a telescopic pole not shown, to maintain contact of the pad 211 with the rail 213 when the aircraft 2 has taken off while remaining above the runway 10.

Here, the positioning of the capture device 210 on the aircraft 2 and its shape are designed to position the contact pad 211 laterally on one side of the aircraft 2, beyond the spacing of its running gears relative to the longitudinal axis of the aircraft 2, so as to avoid interference between the rolling means of the aircraft and the rail 213 arranged on a track 10 at the location where the contact pad 211 passes.

Advantageously, the pantograph 210 can be retracted with the skate 211 into a cavity inside the profile of the wing 206, closed by a hatch during flight.

Preferably, the switch 212 is managed by the control device 208 of the propulsion system to ensure a bevel transition of the electricity supply to the engine 201 by the external electricity collection means 209 and the on-board batteries 203.

According to the invention also, the aircraft takes off from an infrastructure, for example an airport, comprising a runway 10 equipped with the rail 213. The rail 213 is here positioned on a lateral edge of the runway 10 and here extends over the entire length of the runway 10. The position of the rail on the runway and the installation of the capture device 210 on the aircraft are shaped so as to allow contact with the skid 211 of the aircraft 2 during its takeoff path, between the start point and the point where it leaves the runway, while preventing the aircraft's running gear from passing over the rail. Depending on the aircraft, the takeoff path may be different. Equipping the runway with a rail over its entire length therefore makes it possible to adapt it to different types of aircraft.

The rail 213, made of conductive metal, is connected to an external source of electrical energy managed by the infrastructure. This source of electricity, not shown, may be an energy plant specific to the airport or power capacitors connected to an external electrical network. The source of electricity is sized so that the rail transmits to the engine 201, via the capture means 210, the energy necessary for the takeoff of the aircraft 2. Depending on the size of the aircraft or aircraft to take off, the energy source and the components of the transfer devices, 213 and 209, must be sized to provide power ranging from a few hundred kilowatts, for tourist aircraft, to approximately a hundred megawatts for airliners, over durations of a few tens of seconds, the time of takeoff.

In an alternative embodiment, not shown, the sliding contact connection for producing the electrical circuit transmitting the current to the motor 201 can be replaced by a plug connection. In this case, the end of the pantograph comprises a plug element which is plugged into a complementary plug element connected to a cable, which is itself connected to the electricity source of the infrastructure. Said cable is installed on a reel and its end carrying the plug element can slide along the runway. The aircraft drives this end during its travel on the runway and the two plug elements detach when the aircraft moves away from the ground.

In reference to the , according to another embodiment, the transmission of electrical energy to the aircraft 2 is done by induction. In this embodiment, the rail on the runway 10 is replaced by cables 215 buried under the runway and supplied with electric current by the electricity source of the infrastructure, as for example in the PRIMOVE ^® system of the BOMBARDIER firm. In this case, the electricity collection device 216 on board the aircraft 2 comprises a coil 217 which, placed near the cables 215 above the runway 10, transforms the magnetic field created by the cables 215 into an electric current to power the engine 201 of the aircraft 2. The collection device 216 then comprises a pantograph 218 which is controlled so as to keep the coil 217 at a nominal distance from the runway 10 as long as the aircraft 2 is taxiing on the runway 10 or remains nearby.

In the example, the capture device 216 is placed under the fuselage of the aircraft, near the rear, substantially on the longitudinal axis. Indeed, the cables 215 being located under the surface of the runway 10, they cannot have any interference with the rolling system 214 of the aircraft 2. The capture device 216 is thus more easily positioned and controllable.

Furthermore, this embodiment avoids wear between elements rubbing against each other. On the other hand, it can provide a less abrupt transition between the power supply by the infrastructure and that by the on-board source 203, easier to manage by the control device 208.

In another embodiment, not shown, the capture device on the aircraft comprises an antenna intended to capture a beam of waves directed towards this antenna, for example a laser wave or microwaves. In this case, the infrastructure comprising the take-off runway also comprises at least one antenna emitting the wave beam directed towards the antenna. In a first variant, it is a single antenna controlled to follow the antenna of the aircraft during its journey on the runway and, possibly, during its climb in the runway axis. In another variant, these are antennas distributed over the length of the runway which send the energy to the aircraft when it passes at their level.

This embodiment can be combined with the previous ones by installing an antenna which follows the aircraft as it climbs along the axis of the runway.

In another embodiment not shown, the battery is unchanged from the embodiments shown in FIGS. 2 and 3 but the thruster, motor 201 and propeller blades 202, is oversized so as to provide a higher maximum thrust at low speed, during takeoff. In this case, for example, the power of the electric motor 201 is higher and the propeller 202 is variable pitch, so as to adapt to the engine speed during takeoff. The energy transmission means 213 from the infrastructure to the aircraft 2, for their part, are sized to transmit to the thruster the power corresponding to said maximum thrust while the aircraft travels the takeoff runway. Similarly, the equipment of the infrastructure, in particular its energy source supplying the means of the runway transmitting the electrical energy to the aircraft, is sized to provide the energy corresponding to the operation of the thruster at maximum power during takeoff of the aircraft.

The invention also relates to a method using these combined embodiments of the aircraft 2 and the infrastructure to provide energy to the aircraft 2 during takeoff. In this method, the aircraft 2 is capable of taking off thanks to its propulsion system but the infrastructure provides it with the energy necessary for takeoff. The method therefore comprises a phase during which the aircraft 2 travels the runway, driven by its propulsion system so as to acquire sufficient speed to take off. During this phase, the method comprises a step during which the energy required for the propulsion system is transmitted to the aircraft by the infrastructure through cooperation between the aircraft capture device 209 and the transmission device 213. According to one embodiment of the method, this step lasts between the start of the aircraft 2, at a point A of the runway 10, and its takeoff, at a point B of the runway 10. The method may comprise a second step during which the infrastructure supplies the aircraft 2 with energy, while the aircraft climbs while remaining substantially in line with the runway 10. This step is possible in particular with the embodiment using antennas for transmission by energy beam. It is also possible with the other embodiments over a short distance, for example when the pantograph 210 has a telescopic extension to hold the shoe 211 or the reel in position when the aircraft 2 deviates from the runway 10. This step takes place from the take-off point B on the runway, along the trajectory of the aircraft, over a distance which depends on the embodiment of the invention.

In one variant, the runway is longer than the runways usually designed for the takeoff of an aircraft that increases its lift during takeoff by deflecting its flaps at the trailing edge of the wings. In this case, thanks to the runway length, the method includes a step during which it accelerates by rolling on the runway and being supplied with energy by the infrastructure up to a speed greater than its takeoff speed. At the end of this step, during a second step, it gradually increases its lift to take off and makes the transition from the power supply by the external electricity source to the internal electricity source. This variant firstly allows the aircraft to store more energy before operating on its onboard energy source. On the other hand, it allows an easier to control transition between the two energy sources.

In another variant, which can be combined with one of the previous variants, the engines of the aircraft propellers are oversized compared to the on-board energy source and the infrastructure transmits energy corresponding to the maximum power of the engines during the runway run. Advantageously, the propeller blades have a variable pitch allowing to optimize its thrust at low aircraft speeds for a high engine speed. In this way, the thrust of the propeller can be increased compared to autonomous use of the aircraft and the latter can reach the limit speed more quickly before leaving the ground.

This makes it possible to increase the speed of the aircraft during take-off and therefore reduce the on-board energy required, or to minimise the size of the suitable take-off runways.

The invention may be preferentially interesting for short-haul airliners, for which energy consumption during the take-off phase represents a representative share of the total consumption in operation. It may allow the use of electrically powered aircraft, which would represent an ecologically advantageous alternative to land transport, even rail. Indeed, this solution only requires the development of structures at the point of departure and at the point of arrival, without having to create passageways through the regions along the length of the route.

Claims (10)

Assembly comprising an aircraft (2) equipped with an autonomous propulsion system comprising at least one propeller driven by an electric motor (201) and an infrastructure comprising a runway (10), the propulsion system and the runway being configured to allow the aircraft to take off, characterized in that the infrastructure comprises a first device (213), emitting energy, in that the aircraft (2) carries a second device (209), configured to capture the energy of the first device (213) and transform it into energy usable by the electric motor (201) of said at least one propeller, the first (213) and second (209) devices being configured to transmit the energy to each other when the aircraft (2) is on at least part of the runway (10). Assembly according to claim 1, characterized in that the electric motor (201) of said at least one propeller has a given energy consumption to ensure the take-off of the aircraft (2), the infrastructure comprises an energy source configured to provide an energy flow corresponding to said given energy consumption to the first device (213), the first (213) and the second (209) device being sized to pass this energy flow. Assembly according to one of the preceding claims, characterized in that said first (213, 215) and second devices (209, 216) comprise components cooperating by contact, by induction, or by transmission of directed waves to transmit the energy intended for the electric motor (201) of said at least one thruster. Assembly according to one of the preceding claims, characterized in that the first device (213, 215) comprises a component intended to cooperate with the second device for the transfer of energy which is installed at the edge of the track or under a surface of the track. Aircraft (2) equipped with an autonomous propulsion system comprising at least one thruster actuated by an electric motor (201), characterized in that it comprises a said second device (209, 216), configured so as, on the one hand, to cooperate with a said first device (213, 215) emitting energy from an infrastructure, said infrastructure comprising a runway (10) intended to be traveled by the aircraft (2) for its takeoff, to capture energy emitted by the latter, and on the other hand, to transform said energy to make it usable by the electric motor (201) of said at least one thruster. Aircraft (2) according to the preceding claim, in which the propulsion system comprises an on-board electrical energy source (203) designed to transmit a maximum given power to the electric motor (201) of said at least one propeller, characterized in that the electric motor (201) of said at least one propeller and said second device (209,216) are designed to absorb a power greater than said maximum power, said at least one propeller comprising thrust increase means configured in particular for aircraft speeds less than or equal to a given take-off speed. Infrastructure comprising a runway (10) intended to be traveled by aircraft for take-off, characterized in that it comprises a said first device (213, 215) comprising a component installed at the edge of the runway or in the runway intended to transfer electrical energy by contact, by induction or by directed wave to a said second capture device (209, 216) on an aircraft, as well as an energy source configured to power said first device. Method for taking off an aircraft from an infrastructure, the assembly being defined according to one of claims 1 to 4, comprising a step of traveling along the runway (10) by said aircraft (2), characterized in that the infrastructure transmits to the electric motor (201) of said at least one propeller of the aircraft at least part of the energy it needs to take off the aircraft. Method according to the preceding claim, characterized in that, the propulsion system of the aircraft (2) comprising an on-board energy source (203) designed to transmit a given maximum power, it comprises a step of traveling the runway (10) during which the electric motor (201) of said at least one propeller operates at a power greater than said given maximum power, so as to give a catapult effect by the thrust of said at least one propeller. Method according to one of claims 8 or 9, characterized in that it comprises a step during which, the aircraft (2) having taken off from the runway, the infrastructure still transmits energy to the electric motor (201) of said at least one propeller.