AIRCRAFT PROPULSION UNIT COMPRISING AN EXTRACTION FAN

Abstract

PROPULSION ASSEMBLY FOR AIRCRAFT COMPRISING AN EXTRACTION FAN The invention relates to an aircraft propulsion assembly (100) which comprises a nacelle (102) with a front opening (110a) and a rear opening (110b), a propeller (104) driven by an electric motor (106), a fuel cell (108) supplying the electric motor (106) with electric current, an inner channel (112) arranged in the nacelle (102) between the front opening (110a) and the rear opening (110b), where the electric motor (106) and the fuel cell (108) are arranged in the inner channel (112), a motorized fan (114) arranged at the rear portion (102b) for sucking in the air present in the inner channel (112) and for expelling it to the outside through the rear opening (110b), and a control unit (116) controlling the motorized fan (114). With such an arrangement, the outside air cools the interior of the nacelle and the dihydrogen is evacuated. Fig. 2

Description

Title of the invention: PROPULSION ASSEMBLY FOR AIRCRAFT COMPRISING AN EXTRACTION FAN Technical field

[0001] The present invention relates to a propulsion assembly for an aircraft, said propulsion assembly comprising a nacelle, a channel passing through the nacelle from front to rear, and a fan arranged at the rear to suck in and exhaust air from the channel to the outside, as well as an aircraft comprising at least one such propulsion system. STATE OF THE PRIOR ART

[0002] In order to move, an aircraft conventionally comprises at least one propulsion unit. In order to reduce pollutant emissions, a propulsion unit is equipped with an electric motor which rotates a propeller. In the nacelle, various elements ensuring the operation of the propulsion unit, such as the engine, electric generators for example dihydrogen fuel cells, are enclosed in the nacelle.

[0003] In such a nacelle, it is necessary to provide cooling means, in particular of the electric generators and the engine, and means of evacuating the dihydrogen in the event of a leak, in particular when the aircraft is on the ground and the movement of the aircraft cannot be relied upon. Statement of the invention

[0004] An object of the present invention is to provide a propulsion unit which comprises means for cooling the interior of the nacelle and evacuating the dihydrogen, in particular when the aircraft is on the ground.

[0005] For this purpose, a propulsion unit for an aircraft is proposed comprising:

[0006] - a nacelle extending between a front portion and a rear portion, wherein the nacelle has a front opening at the front part and a rear opening at the rear part,

[0007] - a propeller mounted to rotate in front of the nacelle,

[0008] - an electric motor arranged to drive said propeller in rotation,

[0009] - a fuel cell generating an electric current for the electric motor at from dihydrogen,

[0010] - an interior channel arranged in the nacelle and extending between the front opening and the rear opening, where the electric motor and fuel cell are arranged in the inner channel,

[0011] - a motorized fan arranged at the rear part so as to suck the air present in the inner channel and expelling it outside the nacelle through the rear opening, and

[0012] - a control unit arranged to control the starting and stopping of the wind motorized fan.

[0013] With such an arrangement, the outside air cools the interior of the nacelle and the di-hydrogen is evacuated.

[0014] Advantageously, the nacelle comprises a lateral opening, and the propulsion assembly comprises a complementary channel extending between the lateral opening and the internal channel and progressing from the front to the rear of the nacelle.

[0015] Advantageously, the propulsion assembly comprises a door mounted to move between a closed position in which it closes the lateral opening and an open position in which it does not close the lateral opening and actuating means controlled by the control unit and arranged to move the door alternately from the open position to the closed position.

[0016] Advantageously, the propulsion unit comprises at least one heat exchanger mounted in the complementary channel.

[0017] Advantageously, the propulsion unit comprises at least one heat exchanger mounted in the internal channel.

[0018] The invention also proposes an aircraft comprising at least one propulsion unit according to one of the preceding variants. Brief description of the drawings

[0019] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0020] [Fig-1] is a side view of an aircraft comprising a propulsion unit according to the invention,

[0021] [Fig.2] is a schematic representation seen from the side and in section of a propulsion unit according to a first variant of the invention, and

[0022] [Fig.3] is a schematic representation seen from the side and in section of a propulsion unit according to a second variant of the invention.

[0023] DETAILED DESCRIPTION OF EMBODIMENTS

[0024] In the following description, the terms relating to a position are taken with reference to an aircraft in a forward position, that is to say as shown in [Fig.l] where the arrow F shows the direction of forward movement of the aircraft.

[0025] [Fig.l] shows an aircraft 10 which has a fuselage 12 on either side of which a wing 14 is fixed. Under each wing 14 is fixed at least one propulsion unit 100 according to the invention.

[0026] In the following description, and by convention, X is the longitudinal axis of the propulsion unit 100 oriented positively in the direction of advancement of the aircraft 10, Y is the transverse axis of the propulsion unit 100 which is horizontal when the aircraft is on the ground, and Z is the vertical axis or vertical height when the aircraft is on the ground, these three axes X, Y and Z being orthogonal to each other.

[0027] Figs. 2 and 3 each show a propulsion unit 100 according to a variant of the invention.

[0028] The propulsion assembly 100 comprises a nacelle 102 which extends between a front part 102a oriented towards the front of the aircraft 10 and a rear part 102b oriented towards the rear of the aircraft 10.

[0029] The nacelle 102 is conventionally composed of panels 130 fixed next to each other on a chassis.

[0030] The propulsion assembly 100 also comprises an internal channel 112 arranged in the nacelle 102. The internal channel 112 can be delimited by internal walls 132 fixed to the chassis as shown in Figs. 1 and 2, or directly by the panels 130 and the internal channel 112 is then the internal part of the nacelle 102.

[0031] The nacelle 102 has a front opening 110a and a rear opening 110b where each opening 110a-b passes through one of the panels constituting said nacelle 102.

[0032] The front opening 110a is arranged at the front portion 102a and is shaped so as to capture the air outside the nacelle 102 and bring it inside the nacelle 102, and more precisely inside the interior channel 112, and the rear opening 110b is arranged at the rear portion 102b and is shaped so as to bring the air present in the nacelle 102, and more precisely inside the interior channel 112, out towards the outside of the nacelle 102.

[0033] The inner channel 112 thus extends between the front opening 110a and the rear opening 110b and ensures the channeling of the outside and fresh air from the front opening 110a to the rear opening 110b as shown by the arrows in Figs. 2 and 3.

[0034] The propulsion assembly 100 also comprises a propeller 104 mounted so as to be able to rotate in front of the nacelle 102, i.e. in front of the front part 102a, and driven in rotation by an electric motor 106. To this end, the electric motor 106 has a motor shaft 106a mechanically connected to the propeller 104 to make it rotate around its axis, which here coincides with the longitudinal axis X.

[0035] The electric motor 106 is housed in the nacelle 102, and more particularly in the internal channel 112.

[0036] To generate the electric current necessary for the operation of the electric motor 106, the propulsion unit 100 comprises a fuel cell 108 generating an electric current from dihydrogen and dioxygen. The fuel cell 108 is also arranged in the inner channel 112 to allow, among other things, take the oxygen necessary for its operation, from the air present in the internal channel 112. The hydrogen is stored in a tank 134 provided for this purpose in the aircraft 10 and a supply pipe 136 ensures the transfer of the hydrogen to the fuel cell 108.

[0037] By arranging the electric motor 106 and the fuel cell 108 in the interior channel 112, the outside air circulating therein ensures at least partial cooling of said electric motor 106 and said fuel cell 108.

[0038] In the event of a leak of dihydrogen at the level of the fuel cell 108, the dihydrogen which could escape then mixes with the air present in the internal channel 112 to be expelled at the level of the rear opening 110b.

[0039] When the aircraft 100 is in flight, the airflow that passes through the nacelle 102 is generated naturally due to the forward movement of the aircraft 10 and the position of the openings 110a-b. The outside air then circulates naturally from front to rear, cooling the electric motor 106 and the fuel cell 108 that are present in the inner channel 112 and, in the event of a leak, the dihydrogen that mixes with the air is also evacuated to the outside.

[0040] The propulsion assembly 100 also comprises a motorized fan 114 which comprises fan blades 114a and a motor 114b, in particular an electric motor. The motorized fan 114 is arranged at the rear portion 102b so as to suck in the air, and possibly the dihydrogen, present in the inner channel 112 and to expel the air, and possibly the dihydrogen, present outside the nacelle 102 through the rear opening 110b. The fan blades 114a are for example arranged just upstream of the rear opening 110b.

[0041] The rotation of the fan blades 114a therefore ensures forced suction of the air at the front opening 110a and forced discharge of the air at the rear opening 110b.

[0042] To control the starting and stopping of the motorized fan 114, the propulsion assembly 100 also comprises a control unit 116 arranged for this purpose.

[0043] Thus, whether the aircraft 10 is in flight or on the ground, the cooling of the electric motor 106 and the fuel cell 108 as well as the evacuation of any traces of dihydrogen are ensured.

[0044] In the embodiments shown in Figs. 2 and 3, the propulsion unit 100 also comprises at least one heat exchanger 124a which is also mounted in the inner channel 112. The heat exchanger(s) 124a ensure the transfer of calories from a hot fluid to a cold fluid consisting of the air circulating in the inner channel 112.

[0045] The hot fluid can come from any device requiring cooling; for example, it can be a heat transfer fluid coming from the electric motor 106 or from the fuel cell 108 through appropriate pipes.

[0046] The heat exchanger 124a is here arranged just behind the electric motor 106 but it can of course be arranged elsewhere in the internal channel 112 depending on requirements.

[0047] In the embodiments shown in Figs. 2 and 3, the electric motor 106 is traversed by passage channels 106b extending through the electric motor 106 from the front to the rear of said electric motor 106. These passage channels 106b are thus open to allow the air flow coming from the front opening 110a and heading towards the rear opening 110b to pass.

[0048] In the variant of [Fig. 3], the nacelle 102 comprises a lateral opening 110c, that is to say between the front opening 110a and the rear opening 110b, and therefore on the periphery of the nacelle 102 passing through one of the panels constituting the nacelle 102.

[0049] The propulsion assembly 100 then comprises a complementary channel 118 which extends between the lateral opening 110c and the internal channel 112, progressing from the front to the rear of the nacelle 102. Thus, the complementary channel 118 captures the outside air through the lateral opening 110c and conducts it to the internal channel 112 before joining the rear opening 110b.

[0050] In the embodiment presented in [Fig. 3], the propulsion unit 100 comprises at least one heat exchanger 124b which is mounted in the complementary channel 118. As previously, the heat exchanger(s) 124b ensure the transfer of calories from a hot fluid to a cold fluid consisting of the air circulating in the complementary channel 118.

[0051] The hot fluid can come from any device requiring cooling; it can, for example, be a heat transfer fluid coming from the electric motor 106 or from the fuel cell 108 via appropriate pipes.

[0052] Here, the propulsion unit 100 comprises a door 120 which is mounted to move between a closed position in which it closes the lateral opening 110c and an open position in which it does not close the lateral opening 110c. Thus, in the closed position, the outside air does not enter the complementary channel 118 and in the open position the outside air enters the complementary channel 118. The open position can be implemented for example when the aircraft 10 is on the ground and the quantity of outside air coming from the front opening 110a is not sufficient for the needs. The closed position is preferably implemented when the aircraft 10 is in flight and the quantity of outside air coming from the front opening 110a is sufficient for the needs.

[0053] Preferably, the door 120 is mounted to move in rotation on the panels 130 around the hinges.

[0054] The propulsion assembly 100 also comprises actuating means 122 which are controlled by the control unit 116 and which are arranged to move the door 120 alternately from the open position to the closed position. The actuating means 122 comprise, for example, a motor which pivots the door 120 in one direction to move it into the open position and in the opposite direction to move it into the closed position.

[0055] According to an exemplary embodiment, the control unit 116 comprises, connected by a communication bus: a processor or CPU (“Central Processing Unit” in English); a RAM (“Random Access Memory” in English); a ROM (“Read Only Memory” in English), for example a Flash memory; a data storage device, such as a hard disk HDD (“Hard Disk Drive” in English), or a storage media reader, such as an SD (“Secure Digital” in English) card reader; at least one communication interface allowing the control unit 116 to interact with avionics equipment of the aircraft 10, in particular the engine 114b and the actuation means 122.

[0056] The processor is capable of executing instructions loaded into RAM from ROM, external memory (not shown), a storage medium, such as an SD card, or a communications network (not shown). When the control unit 116 is powered on, the processor is capable of reading instructions from RAM and executing them. These instructions form a computer program causing the processor to implement the behaviors, steps, and algorithms described herein.

[0057] All or part of the behaviors, steps and algorithms described herein may thus be implemented in software form by executing a set of instructions by a programmable machine, such as a DSP (Digital Signal Processor) or a microcontroller, or be implemented in hardware form by a machine or a dedicated component (chip) or a set of components (chipset), such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specified Integrated Circuit). Generally speaking, the control unit 116 comprises electronic circuitry arranged and configured to implement the behaviors, steps and algorithms described herein.

Claims

Claims

1. A propulsion assembly (100) for an aircraft (10) comprising: - a nacelle (102) extending between a front portion (102a) and a rear portion (102b), wherein the nacelle (102) has a front opening (110a) at the front portion (102a) and a rear opening (110b) at the rear portion (102b), - a propeller (104) mounted rotatably in front of the nacelle (102), - an electric motor (106) arranged to rotate said propeller (104), - a fuel cell (108) generating an electric current for the electric motor (106) from dihydrogen, - an internal channel (112) arranged in the nacelle (102) and extending between the front opening (110a) and the rear opening (110b), wherein the electric motor (106) and the fuel cell (108) are arranged in the inner channel (112),- a motorized fan (114) arranged at the rear portion (102b) so as to suck in the air present in the inner channel (112) and expel it outside the nacelle (102) through the rear opening (110b), and - a control unit (116) arranged to control the starting and stopping of the motorized fan (114).,

2. Propulsion assembly (100) according to claim 1, characterized in that the nacelle (102) comprises a lateral opening (110c), and in that the propulsion assembly (100) comprises a complementary channel (118) extending between the lateral opening (110c) and the internal channel (112) and progressing from the front to the rear of the nacelle (102).

3. Propulsion assembly (100) according to claim 2, characterized in that it comprises a door (120) mounted to move between a closed position in which it closes the lateral opening (110c) and an open position in which it does not close the lateral opening (110c) and actuating means (122) controlled by the control unit (116) and arranged to move the door (120) alternately from the open position to the closed position.

4. Propulsion assembly (100) according to one of claims 2 or 3, characterized in that it comprises at least one heat exchanger (124b) mounted in the complementary channel (118).

5. Propulsion assembly (100) according to one of claims 1 to 4, characterized in that it comprises at least one heat exchanger (124a) mounted in the internal channel (112).

6. Aircraft (10) comprising at least one propulsion unit (100) according to one of the preceding claims.

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