AIRCRAFT PROPULSION ARRANGEMENT WITH AT LEAST ONE PRESSURE RELIEF DEVICE AND AIRCRAFT WITH AT LEAST ONE SUCH PROPULSION UNIT

Description

[0001] The present application relates to an aircraft propulsion assembly comprising at least one overpressure device as well as to an aircraft comprising at least one such propulsion assembly.

[0002] According to an example visible on the figure 1 , an aircraft 10 comprises a fuselage 12, wings 14 which extend on either side of the fuselage as well as propulsion assemblies 16 connected to the wings 14 and positioned below the wings 14. According to a configuration visible on the figure 2 , a propulsion assembly 16 comprises a turboprop 18, a propeller 20 driven in rotation by the turboprop 18 as well as a nacelle 22 in which the turboprop 18 is positioned, the propeller 20 being positioned in front and outside the nacelle 22.

[0003] According to one configuration, the turboprop 18 operating on hydrogen, the aircraft 10 comprises a hydrogen supply system 24. The hydrogen being stored in a cryogenic state, the hydrogen supply system 24 is configured to compress the hydrogen to a very high pressure, vaporize it and then reheat it before supplying the turboprop 18.

[0004] In the event of an incident, the hydrogen supply system 24 can generate a rapid increase in pressure inside the nacelle 22. To withstand such overpressure, the nacelle 22 is reinforced. This solution is not satisfactory because it leads to a significant increase in the mass of the nacelle 22.

[0005] The present invention aims to remedy all or part of these drawbacks.

[0006] To this end, the invention relates to an aircraft propulsion assembly as claimed in claim 1. Patent applications US2020 / 130811 and US2011 / 297787 describe the preamble of claim 1.

[0007] The invention also relates to an aircraft comprising at least one such propulsion assembly.

[0008] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to the appended drawings, among which: Fig. 1 is a perspective view of an aircraft, Fig. 2 is a side view of a propulsion assembly illustrating an embodiment of the prior art, Fig. 3 is a side view of a propulsion assembly illustrating a first embodiment of the invention, Fig. 4 is a schematic top view of part of the propulsion assembly fairing visible on the figure 3 , Fig. 5 is a schematic section along line VV of the figure 4 , Fig. 6 is a schematic top view of a portion of a fairing of a propulsion assembly illustrating another embodiment of the invention, Fig. 7 is a schematic top view of a portion of a fairing of a propulsion assembly illustrating another embodiment of the invention, Fig. 8 is a schematic section along line VIII-VIII of the figure 6 , Fig. 9 is a schematic side view of a portion of a fairing of a propulsion assembly illustrating another embodiment of the invention, Fig. 10 is a schematic top view of part of the fairing visible on the figure 9 , Fig. 11 is a schematic section along line XI-XI of the figure 10 , Fig. 12 is a schematic perspective view of a portion of a fairing of a propulsion assembly illustrating another embodiment of the invention.

[0009] According to an embodiment visible on the figure 3 , a propulsion assembly 30 comprises a motor 32, a propeller 34 driven in rotation by the motor 32 as well as a nacelle 36 which forms an aerodynamic fairing around the motor 32, the propeller 34 being positioned outside and at the front of the nacelle 36.

[0010] The motorization 32 comprises an axis of rotation A32 substantially parallel to that of the propeller 34.

[0011] For the remainder of the description, a longitudinal direction is a direction parallel to the axis of rotation A32 of the motor 32. A transverse plane is a plane perpendicular to the axis of rotation A32 of the motor 32. The concepts front and rear refer to the direction of air flow around the motor 32 in flight, which flows from front to rear.

[0012] According to one application, an aircraft comprises at least one propulsion assembly 30 positioned under a wing 38 of the aircraft and connected to the latter.

[0013] Of course, the invention is not limited to this application or to this positioning for the propulsion assembly 30.

[0014] The propulsion assembly 30 is supplied with fuel by a fuel supply system 40 positioned partly in the nacelle 36. According to one configuration, the fuel is in gaseous form and the fuel supply system is therefore a gaseous fuel supply system. According to another configuration, the fuel is in liquid cryogenic form and the fuel supply system 40 is therefore a liquid cryogenic fuel supply system.

[0015] According to one configuration, the propulsion assembly operating on hydrogen, the fuel supply system 40 comprises at least one element among a high pressure pump, a vaporization system, a heat exchanger, conduits, shut-off valves and buffer tanks. Of course, this list is not exhaustive. In addition, the invention is not limited to hydrogen as fuel.

[0016] The nacelle 36 comprises a primary structure ensuring, among other things, the absorption of forces as well as a secondary structure, in the form of an aerodynamic fairing 46, supported by the primary structure.

[0017] This fairing 46 comprises a set of juxtaposed walls, each having a face in contact with an air flow when the aircraft is in flight.

[0018] According to one embodiment, the fairing 46 comprises a central portion 46.1 positioned under the wing 38 and a rear portion 46.2 offset rearwardly relative to a vertical plane passing through the trailing edge 38.1 of the wing 38.

[0019] According to another embodiment, the fairing 46 does not include any portion offset rearwardly relative to a vertical plane passing through the trailing edge 38.1 of the wing 38.

[0020] The first and second side walls 48.1, 48.2 are substantially symmetrical with respect to a median plane PM (visible on the figure 4 ), substantially vertical, containing the trailing edge 50.

[0021] According to an embodiment visible on the various figures 3 à 11 , the first and second side walls 48.1, 48.2 form, in a transverse plane, an approximately V-shaped shape with a downwardly oriented tip, the trailing edge 50 extending to the central part 46.1 of the fairing 46. According to another embodiment visible on the figure 12 , the trailing edge 50 is substantially vertical and the fairing 46 comprises a lower wall 52' connecting the first and second side walls 48.1, 48.2 to the trailing edge 50.

[0022] Regardless of its configuration, the fairing 46 separates an interior zone and an exterior zone, the engine 32 and at least part of the fuel supply system 40 being positioned in the interior zone.

[0023] According to a characteristic of the invention, the propulsion assembly 30 comprises a pressure relief device 54 configured to occupy an inactivated state, when the interior zone has a pressure lower than a given threshold, in which the pressure relief device 54 forms a substantially fluid-tight barrier between the interior and exterior zones, as well as an activated state, when the interior zone has a pressure greater than or equal to the given threshold, in which the pressure relief device 54 allows the interior and exterior zones to communicate.

[0024] According to one configuration, the fairing 46 comprises first and second side walls 48.1, 48.2 as well as a trailing edge 50 positioned at the rear end of the fairing 46, the side walls 48.1, 48.2 joining at the trailing edge 50. In the presence of a rear portion 46.2 (at the rear of the wing 38), the fairing 46 comprises an upper wall 52, positioned in a substantially horizontal plane, connecting the first and second side walls 48.1, 48.2 and extending to the trailing edge 50.

[0025] The pressure relief device 54 comprises at least one opening 56, passing through the fairing 46, which allows the interior and exterior zones to communicate, as well as, for each opening 56, at least one door 58 configured to occupy a closed position, corresponding to the inactivated state of the pressure relief device 54, in which the door 58 closes the opening 56, and an open position, corresponding to the activated state of the pressure relief device 54, in which the door 58 at least partially clears the opening 56.

[0026] Each door 58 extends in line with the fairing 46 so as to limit aerodynamic disturbances.

[0027] In addition, the overpressure device 54 comprises, for each door 58, at least one articulation 60 connecting the door 58 and a fixed part of the propulsion assembly 30, such as the primary or secondary structure of the nacelle 36, as well as at least one locking / unlocking system 62 spaced from the articulation 60 and configured to occupy a locked state in which the locking / unlocking system 62 maintains the door 58 in the closed position and an unlocked state in which the locking / unlocking system allows the door 58 to move from the closed position to the open position. According to one configuration, the locking / unlocking system 62 is arranged at the end of the door 58 opposite the articulation 60.

[0028] According to one embodiment, the hinge 60 is configured such that the door 58 moves away from the fairing 46 towards the exterior area when it moves from the closed position to the open position.

[0029] According to one configuration, each joint 60 comprises several swan-neck type hinges. According to another configuration, each joint 60 comprises several piano-type hinges.

[0030] According to one arrangement, for each door 58, the articulation 60 has a pivot axis A60 positioned approximately in a transverse plane and at the front of the door 58. This arrangement makes it possible to prevent an air flow flowing around the fairing 46 in flight from forcing the door 58 to open.

[0031] According to one embodiment, the overpressure device 54 comprises, for each door 58, at least one retaining means 64, such as a cable for example, connecting the door 58 to a fixed part of the propulsion assembly and limiting the opening of the door 58 beyond the open position. The retaining means 64 makes it possible to limit the opening of the door 58 to a predetermined passage section.

[0032] Each retaining means 64 has a first end 64.1 connected to the door 58 and spaced from the articulation 60 as well as a second end 64.2 connected to the nacelle 36, in particular to its primary or secondary structure, and spaced from the articulation 60.

[0033] According to one configuration, each locking / unlocking system 62 is configured to automatically switch from the locked state to the unlocked state as soon as the pressure in the interior zone becomes greater than or equal to the given threshold.

[0034] According to another configuration, each locking / unlocking system 62 is controllable. According to one embodiment, the overpressure device 54 comprises at least one hydrogen leak detector, for example taking the form of a hydrogen detector, configured to detect the presence of hydrogen in the interior zone of the fairing 46 or a pressure sensor 66 positioned in the interior zone and configured to measure a pressure in the interior zone, as well as a control 68 provided by the leak sensor or the pressure sensor 66 and configured to control each locking / unlocking system 62 and command a change of state of each locking / unlocking system 62 from the locked state to the unlocked state as soon as the pressure measured by the pressure sensor 66 is greater than or equal to the given threshold or when a leak is detected.Additionally or alternatively, the overpressure device 54 comprises a control operable by a person, such as the pilot for example, positioned in the cockpit, configured to cause a change in state of the overpressure system.

[0035] The pressure relief device 54 may comprise, for each door 58, at least one actuator connected to the door and configured to cause a change in position of the door 58.

[0036] According to one arrangement, the pressure relief device 54 comprises at least one seal 70 interposed between the fairing 46 and each door 58 when the latter is in the closed position.

[0037] According to a first embodiment visible on the figures 3 à 5 , the opening 56 is positioned at the first side wall 48.1. The opening 56 is delimited by a first substantially vertical edge 56.1, positioned in front of the opening 56 and extending to the trailing edge 50, a second substantially horizontal edge 56.2, connecting the first edge 56.1 and the trailing edge 50 as well as a third edge 56.3 which follows the trailing edge 50 and connects the first and second edges 56.1, 56.2. According to one configuration, the second edge 56.2 follows the junction zone connecting the first side wall 48.1 and the upper wall 52.

[0038] According to this first embodiment, the pressure relief device 54 comprises a single door 58 delimited by first, second and third sides which follow, when the door 58 is in the closed position, respectively the first, second and third edges 56.1, 56.2, 56.3 of the opening 56.

[0039] The articulation 60 is positioned at the first edge 56.1 of the opening 56. The overpressure device 54 comprises two locking / unlocking systems 62 distributed over the third edge 56.3 of the opening 56. At least one seal 70 is connected to the nacelle 36, in particular to its primary or secondary structure, and extends along the second and third edges 56.2, 56.3.

[0040] According to a second embodiment visible on the figures 6 And 8 , the opening 56' is positioned at the level of the first and second side walls 48.1, 48.2. The opening 56' is delimited by: a. a first edge 56.1' which extends over the first side wall 48.1 and connects the trailing edge 50 and the top wall 52, b. a second edge 56.2' which extends over the second side wall 48.2 and connects the trailing edge 50 and the top wall 52, the first and second edges 56.1', 56.2' being positioned in the same transverse plane, c. a third edge 56.3' connecting the first edge 56.1' and the trailing edge 50, positioned at the junction area connecting the first side wall 48.1 and the top wall 52, d. a fourth edge 56.4' connecting the second edge 56.2' and the trailing edge 50, positioned at the junction area connecting the second side wall 48.2 and the top wall 52.

[0041] According to this second embodiment, the pressure relief device 54 comprises first and second doors 58, 58' extending respectively the first and second side walls 48.1, 48.2. The first door 58 comprises first, second and third sides which follow, when the first door 58 is in the closed position, respectively the first edge 56.1', the third edge 56.3' and the trailing edge 50 of the opening 56'. The second door 58' comprises first, second and third sides which follow, when the second door 58' is in the closed position, respectively the second edge 56.2', the fourth edge 56.4' and the trailing edge 50 of the opening 56'.

[0042] According to this second embodiment, the pressure relief device 54 comprises at least one first articulation 60 connecting the first door 58 to the first edge 56.1' of the opening 56' as well as at least one second articulation 60' connecting the second door 58' to the second edge 56.2' of the opening 56'.

[0043] The overpressure device 54 comprises locking / unlocking systems 62 distributed on the third sides of the first and second doors 58, 58', located at the trailing edge 50 when they are in the closed position. In addition, the overpressure device 54 comprises a first seal 70 positioned at the third side of the first door 58, interposed between the first and second doors 58, 58' when they are in the closed position, a second seal 70' positioned at the third edge 56.3' of the opening 56', interposed between the first door 58 and the nacelle 36, as well as a third seal 70" positioned at the fourth edge 56.4' of the opening 56', interposed between the second door 58' and the nacelle 36.

[0044] According to a third embodiment visible on the figure 7 and close to that visible on the figure 6 , the overpressure device 54 comprises an opening 56' as well as first and second doors 58, 58' substantially identical to those of the second embodiment. In addition, the nacelle comprises a median reinforcement 72 having a rear edge 72.1 which follows the trailing edge 50 and against which the first and second doors 58, 58' bear in the closed position. According to this third embodiment, the first seal 70 is connected to the median reinforcement 72 and not to the first door 58.

[0045] According to a fourth embodiment visible on the figures 9 à 11 , the opening 56" is positioned at the level of the upper wall 52. It is delimited by a first edge 56.1" positioned in a transverse plane connecting the junction zones which connect the upper wall 52 and the first and second side walls 48.1, 48.2, a second edge 56.2" which follows the junction zone connecting the upper wall 52 and the first side wall 48.1 and which extends from the first edge 56.1" to the trailing edge 50 as well as a third edge 56.3" which follows the junction zone connecting the upper wall 52 and the second side wall 48.2 and extends from the first edge 56.1" to the trailing edge 50.

[0046] According to this fourth embodiment, the pressure relief device 54 comprises a single door 58 delimited by first, second and third sides which follow, when the door 58 is in the closed position, respectively the first, second and third edges 56.1", 56.2", 56.3" of the opening 56".

[0047] The joint 60 is positioned at the first edge 56.1" of the opening 56". The pressure relief device 54 comprises at least first and second locking / unlocking systems 62, 62', at least one first locking / unlocking system 62 being positioned at the second edge 56.2" of the opening 56", at least one second locking / unlocking system 62' being positioned at the third edge 56.3" of the opening 56". According to this fourth embodiment, the pressure relief device 54 comprises a first seal 70, connected to the nacelle 36, which extends along the second edge 56.2" of the opening 56 as well as a second seal 70', connected to the nacelle 36, which extends along the third edge 56.3".

[0048] Of course, the invention is not limited to the embodiments previously described. Thus, as illustrated in the figure 12, the opening 56 and the door 58 may each have more than three edges or sides and have different geometries.

[0049] Whatever the embodiment, the opening 56 must have a sufficient surface area, greater than 500 cm 2< , for example around 4000 cm 2< , to limit the risks of damage to the fairing 46 in the event of excess pressure inside the latter.

Claims

1. Aircraft propulsion unit comprising a motor (32), a fuel supplying system (40) configured to supply fuel to the motor (32), and a fairing (46) that separates an inner zone and an outer zone, the motor (32) and at least part of the fuel supplying system (40) being positioned in the inner zone, the propulsion unit comprising a pressure relief device (54) configured to assume either an inactivated state, when the inner zone exhibits a pressure lower than a given threshold, and in which the pressure relief device (54) forms a substantially leaktight barrier between the inner and outer zones, or an activated state, when the inner zone exhibits a pressure greater than or equal to the given threshold, and in which the pressure relief device (54) comprises at least one opening (56, 56') that goes through the fairing (46) and establishes communication between the inner and outer zones, and, for each opening (56, 56'), at least one door (58) configured to assume a closed position, corresponding to the inactivated state of the pressure relief device (54), in which the door (58) closes off the opening (56, 56'), and an open position, corresponding to the activated state of the pressure relief device (54), in which the door (58) at least partially uncovers the opening (56, 56'), the fairing (46) comprising first and second lateral walls (48.1, 48.2) and a trailing edge (50), characterized in that the lateral walls (48.1, 48.2) meet at the trailing edge (50), and in that the opening (56, 56') of the pressure relief device (54) is positioned in at least one of the first and second lateral walls (48.1, 48.2) and extends to the trailing edge (50).

2. Propulsion unit according to Claim 1, characterized in that the pressure relief device (54) comprises: - for each door (58), at least one articulation (60) connecting the door (58) and a fixed part of the propulsion unit, - at least one locking / unlocking system (62) configured to assume a locked state, in which the locking / unlocking system (62) keeps the door (58) in the closed position, and an unlocked state, in which the locking / unlocking system allows the door (58) to move from the closed position to the open position.

3. Propulsion unit according to the preceding claim, characterized in that each locking / unlocking system (62) is configured to automatically move from the locked state to the unlocked state as soon as the pressure in the inner zone becomes greater than or equal to the given threshold.

4. Propulsion unit according to Claim 2, characterized in that the pressure relief device (54) comprises a controller configured to bring about a change in state of the locking / unlocking system (62).

5. Propulsion unit according to the preceding claim, characterized in that the pressure relief device (54) comprises, for each door (58), at least one actuator connected to the door and configured to bring about a change in position of the door (58).

6. Propulsion unit according to one of Claims 2 to 5, characterized in that the articulation (60) is configured such that the door (58) is moved away from the fairing (46) in the direction of the outer zone when the door (58) moves from the closed position to the open position, the articulation (60) having a pivot axis (A60) positioned approximately in a transverse plane at the front of the door (58).

7. Propulsion unit according to one of Claims 2 to 6, characterized in that the pressure relief device (54) comprises, for each door (58), at least one retaining means (64) connecting the door (48) to a fixed part of the propulsion unit.

8. Propulsion unit according to one of Claims 2 to 7, characterized in that the pressure relief device (54) comprises at least one seal (70) interposed between the fairing (46) and each door (58) when the latter is in the closed position.

9. Propulsion unit according to any one of the preceding claims, characterized in that the opening (56') of the pressure relief device is positioned in the first and second lateral walls (48.1, 48.2), and in that the pressure relief device (54) comprises a first door (58) which extends the first lateral wall (48.1) and a second door (58') which extends the second lateral wall (48.2).

10. Aircraft comprising at least one propulsion unit according to one of the preceding claims.