Aircraft with integrated fuselage and all-electric propulsion

Abstract

The present invention relates to an aircraft (1) comprising: a main fuselage formed of a central wing (10), centered on a longitudinal axis (X10); two lateral wings (20) mechanically connected to the central wing (10); and at least one propulsion system (40); characterized in that the aircraft (1) comprises an electrical energy storage system (30) electrically connected to the propulsion system (40) and providing fully electric propulsion for the aircraft (1). Abstract figure: 1

Description

Title of the invention: Aircraft with integrated fuselage and all-electric propulsion. Technical field

[0001] The present invention relates to a blended wing body (BWB) aircraft with all-electric propulsion. The field of the invention is that of air transport for passengers and / or cargo. Previous art

[0002] Different aircraft architectures are known to date.

[0003] The cylindrical / cigar-shaped fuselage with two lateral wings is the most common design. This design has met the need for long-distance, subsonic flights for decades. However, it also presents major drawbacks. The wings have small lift surfaces, requiring large airports and leading to numerous logistical and boarding complexities. The wings also have a limited wingspan to allow for easy parking at terminals and maneuvering on the ground with minimal difficulty. For example, some large-capacity aircraft models have required extensive airport upgrades / redevelopment in various countries.The small fuselage dimensions, designed to reduce drag, and its nearly circular cross-section, which supports pressurization, sometimes make life on board very uncomfortable (feelings of suffocation, risk of claustrophobia, difficult movement for crew and passengers, complex cabin layout). The concentration of mass in the fuselage relative to its small size results in a very high empty weight. The empty weight to takeoff weight ratio is often between 0.5 and 0.6, meaning that nearly 50% of the propulsion power (related to fuel consumption) is not used for passenger transport.

[0004] The so-called flying wing architecture, generally with a large wingspan, incorporates a sweep to address longitudinal stability issues. The drag generated is the lowest, and this solution offers a better lift-to-drag ratio. Passengers are housed within the thickness of the wing profile, but the wingspan must be considerably increased. However, this makes ground operations more difficult. Furthermore, the non-cylindrical habitable volumes make the structure more complex to build. Finally, due to efficient mass distribution, the empty mass to takeoff mass ratio is approximately 0.4.

[0005] The blended wing body (BWB) architecture has been studied particularly for transonic flight, with a central wing (body) and fixed lateral wings. Such an aircraft has no sweep but nevertheless exhibits excellent longitudinal stability thanks to its special wing profile. Document WO2021123540 describes an example of a BWB aircraft and its advantages. This aircraft can be electrically, thermally, or hybrid-powered. Description of the invention

[0006] The object of the present invention is to provide an improved aircraft.

[0007] To this end, the invention relates to an aircraft comprising: - a main fuselage consisting of a central wing, centered on a longitudinal axis; - two lateral wings mechanically connected to the central wing; and - at least one propulsion system;

[0008] characterized in that the aircraft includes an electric battery system electrically connected to the propulsion system and providing fully electric propulsion of the aircraft.

[0009] Thus, the invention makes it possible to propose a new generation of BWB aircraft, meeting current environmental challenges. These aircraft can be optimized in terms of propulsion, aerodynamics, stability, compactness, flight speed, operating radius, short takeoff / landing capability, and payload.

[0010] According to other advantageous features of the invention, taken individually or in combination:

[0011] The propulsion system comprises: a fairing; a nozzle disposed at the rear of the fairing and centered on a nozzle axis; a drive shaft disposed in the fairing and centered on a drive axis; and a shrouded propeller, mounted on the drive shaft inside the fairing.

[0012] The nozzle axis is inclined relative to the motor axis, with an angle formed between the nozzle axis and the motor axis which is between 1 and 30 degrees, for example equal to 20 degrees.

[0013] According to different variants: - The nozzle axis is inclined upwards relative to the engine axis. - The nozzle axis is inclined to the side relative to the engine axis. - The nozzle axis is inclined downwards relative to the engine axis. - The nozzle axis is inclined upwards and to the side relative to the motor axis. - The nozzle axis is inclined downwards and to the side relative to the motor axis.

[0014] In the lower part, the fairing is integral with the central wing.

[0015] The aircraft includes a fin mounted on the fairing.

[0016] The propulsion system includes a control surface positioned in line with the nozzle.

[0017] The control surface is housed partly in the nozzle and partly outside the nozzle.

[0018] The rudder is mounted on a pivot axis having a lower end housed in part lower part of the fairing, an intermediate section housed in the upper part of the fairing, and an upper end housed in the fin.

[0019] The rudder has a lower part located in the extension of the nozzle and an upper part located in the extension of the fin, above the fairing.

[0020] Between the lower part and the upper part, the rudder has an intermediate hollowed-out part receiving the fairing in the upper part.

[0021] The central wing has a hollow area formed in front of the propulsion system for the air intake and having a profile in tangency with the propulsion system.

[0022] At least one propulsion system is positioned on the central wing.

[0023] The aircraft comprises two propulsion systems mounted on the central wing, respectively to the left and right of a vertical central plane of the aircraft.

[0024] The central wing has a rear door.

[0025] The rear door is located between the two propulsion systems.

[0026] Preferably, the aircraft is configured for the transport of passengers.

[0027] Preferably, the aircraft can be configured to carry between 10 and 30 passengers. Description of the figures

[0028] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0029] [Fig. 1] is a perspective view from the front of an aircraft according to the invention.

[0030] [Fig.2] is a rear perspective view of the aircraft of [Fig. 1].

[0031] [Fig.3] is a top view of the aircraft of [Fig.1].

[0032] [Fig.4] is a rear view of the aircraft of [Fig.1].

[0033] [Fig.5] is a rear side perspective view showing the rear part of the aircraft of [Fig.1], in particular its propulsion systems.

[0034] [Fig.6] is a partial view of the rear part of the aircraft, on the left side of [Fig.5], showing one of the propulsion systems.

[0035] [Fig.7] is a section along line VILVII in [Fig.6], showing the propulsion system.

[0036] [Fig.8] is a cross-section similar to [Fig.6], showing different positions of the rudder equipping the propulsion system.

[0037] [Fig.9] is a top view of the propulsion system of the [Fig.6].

[0038] [Fig. 10] is a section along line XX in [Fig.9], showing the propulsion system.

[0039] [Fig. 11] is a top view similar to [Fig.9], from another angle of view and partially in transparency, with the rudder on the left side.

[0040] [Fig.12] is a top view analogous to [Fig.11], with the rudder on the right side. Detailed description of the invention

[0041] Figures 1 to 12 show a BWB-type aircraft (1) according to the invention, having a longitudinal axis (X10) or roll axis, a transverse axis (Y10) or pitch axis, and a vertical axis (Z10) or yaw axis. The aircraft (1) comprises a main fuselage formed by a central wing (10), centered on the longitudinal axis (X10); and two lateral wings (20) mechanically connected to the central wing (10), on either side of the vertical median plane (Pxz). According to various embodiments, the lateral wings (20) may be fixed to the central wing (10) or pivotable relative to the central wing (10).

[0042] With reference to [Fig. 3], the aircraft (1) may have a length Long of between 4 and 20 meters, for example 12 meters, and a wingspan Env of between 10 and 60 meters, for example 33 meters. Preferably, the ratio between the wingspan Env and the length Long is between 1.5 and 4.

[0043] The BWB architecture of the aircraft (1) allows for a more uniform distribution of aerodynamic lift forces. Since the central wing (10) is lifting, the wings (20) do not need to provide as much lift as in the case of a tubular-fuselage aircraft. Thus, the bending moments transmitted from the wings (20) to the fuselage are less intense. In addition, the large wing cross-section (20) at the junction with the fuselage helps to avoid excessive concentration of mechanical stress. These characteristics contribute to simplifying the transfer of forces and thus allow for two things: reducing the mass of the structure or lengthening the wings (20).

[0044] Thanks to the integrated fuselage architecture and high-mechanical-property composite materials, the aircraft (1) can be designed with a wingspan Env exceeding 33 meters and can carry up to 19 passengers. The wingspan Env-to-passenger ratio therefore exceeds the threshold of 1.7.

[0045] The aircraft (1) can be used for passenger transport, freight transport, rapid rescue operations and military operations, reducing the energy requirements associated with its activities.

[0046] Furthermore, the aircraft (1) is designed according to the “cross-laying” method, which is a geometric method for defining the location of the lateral wings (20) on the central wing (10) within the framework of defining a BWB aircraft. More Specifically, the cross-bracing allows us to define the location of the wing root of the lateral wings (20) relative to the chord of the central wing (10) of the aircraft (1). Depending on the airfoils used on the central wing (10), the position of the root can vary; it will therefore be expressed as a percentage of the chord, with point 0 being the nose of the aircraft (1). Preferably, the root is located at 70% of the chord, but can vary from 50% to 100% depending on the choice of wing airfoil (10, 20).

[0047] The aircraft (1) includes an electrical energy storage system (30) and two propulsion systems (40) electrically connected to the electric battery system (30). The electrical energy storage system (30) may include batteries, capacitors, capacitors, flywheels, or any other suitable means.

[0048] The system (30) is located in the central wing (10). The system (30) provides fully electric propulsion for the aircraft (1). In other words, the aircraft (1) has no thermal or hybrid propulsion.

[0049] The two propulsion systems (40) are mounted on the central wing (10), respectively to the left and right of the vertical central plane (Pxz) of the aircraft (1), symmetrically with respect to this plane (Pxz). A spacing E40 is provided between the two propulsion systems (40). By way of example, this spacing (E40) can be between 2 and 20 meters.

[0050] Each propulsion system (40) comprises a fairing (41); a nozzle (42) disposed at the rear of the fairing (41) and centered on a nozzle axis (A42); a drive shaft (43) disposed within the fairing (41) and centered on a drive axis (A43); and a shrouded propeller (44) mounted on the drive shaft (43) inside the fairing (41). The components of the system (40) do not protrude from the nozzle (42) at the rear. The nozzle (42) can be secured to the fairing (41) by any suitable means; for example, the nozzle (42) can be a component mounted on the rear of the fairing (41).

[0051] In the embodiment shown in Figures 1 to 12, the nozzle axis (A42) is inclined upwards relative to the engine axis (A43), with an angle (c) formed between the nozzle axis (A42) and the engine axis (A43) that is between 1 and 30 degrees, for example, 20 degrees. The angle (c) of the nozzle (42) compensates for the pitching moment generated on the nose of the aircraft (1) by the power and position of the propulsion systems (40).

[0052] According to various variants not shown, the nozzle axis (A42) can be inclined in different ways relative to the drive axis (A43): sideways, downwards, upwards and sideways, or downwards and sideways. In all cases, the nozzle axis (A42) is located within a cone delimited by an angle between 1 and 30 degrees relative to the drive axis (A43). The nozzle (42) inclined sideways compensates for yaw torque.

[0053] Advantageously, the nozzle axis (42) is offset relative to the aircraft's center of gravity (1). The offset between the nozzle axis (42) and the axis (X10) in the vertical plane (Pxz) helps to reduce the pitching moment generated around the pitch axis (Y10), that is, the moment that tends to make the aircraft (1) pitch down, compared to a configuration without offset. This is particularly advantageous during takeoff. Similarly, the offset between the nozzle axis (A42) and the axis (X10) in the horizontal plane (Pxy) helps to reduce the moment generated around the yaw axis (Z10) compared to a configuration without offset. This moment tends to make the nose of the aircraft (1) point to the side opposite the propulsion system—port or starboard. This makes it easier to maintain control of the aircraft (1) in the event of the loss of a propulsion system (40).

[0054] In its lower part, the fairing (41) is integral with the central wing (10). This allows the position of the propulsion axis, corresponding to the nozzle axis (A42), to be lowered, thereby reducing the parasitic pitching moment exerted on the nose of the aircraft (1). Furthermore, this makes the aircraft structure (1) lighter, which reduces propulsion energy consumption and moves the center of gravity forward, thus improving stability.

[0055] The aircraft (1) includes a fin (50) mounted on the fairing (41). This configuration is much more responsive to crosswinds than a cylindrical fairing without a fin, which improves lateral (yaw) stability.

[0056] The propulsion system (40) includes a control surface (60) positioned in line with the nozzle (42). The control surface (60) is blown by the air exiting the nozzle (42). The blown control surface (60) improves lateral control at low speeds, therefore during takeoff and landing. Furthermore, in the event of a failure of one of the propulsion systems (40), the thrust direction of the remaining system (40) reduces the parasitic yaw moment induced by the thrust itself, which improves aircraft control (1). Finally, the positioning of the control surface (60) above the slow boundary layer improves aircraft stability (1).

[0057] In the embodiment shown in the figures, the control surface (60) is partially housed within the nozzle (42) and partially outside the nozzle (42). The control surface (60) is mounted on a pivot axis (61) having a lower end (611) housed in the lower part of the fairing (41), an intermediate section (612) housed in the upper part of the fairing (41), and an upper end (613) housed in the fin (50). The control surface (60) has a lower portion (66) located in line with the nozzle (42) and an upper portion (67) located in line with the fin (50), above the fairing (41). Between the lower portion (66) and the upper portion (67), the control surface (60) has a hollowed-out intermediate portion (67) receiving the fairing (41) at its upper end.

[0058] According to variants not shown, the control surface (60) could be entirely in the nozzle (42), or entirely outside the nozzle (42).

[0059] The central wing (10) has a hollow area (16) formed in front of the propulsion system (40) for air intake. The hollow area (16) has a profile tangent to the propulsion system (40). The fairing (41) has a recessed area (416) above the hollow area (16). This allows for a better distribution of the load transfer, and therefore a reduction in the weight of the central wing (10).

[0060] The central wing (10) has a rear door (80) for boarding passengers or cargo. The rear door (80) is located between the two propulsion systems (40), as shown in [Fig. 4].

[0061] Furthermore, the aircraft (1) can be configured differently from Figures 1 to 12 without departing from the scope of the invention, which is defined by the claims. In particular, the propulsion system (40) can have any configuration suitable for the intended application. Moreover, the technical characteristics of the various embodiments and variants mentioned above can be combined, in whole or in part. Thus, the aircraft (1) can be adapted in terms of cost, functionality, and performance.

Claims

Demands

1. Aircraft (1) comprising: - a main fuselage formed of a central wing (10), centered on a longitudinal axis (X10); - two lateral wings (20) mechanically connected to the central wing (10); and - at least one propulsion system (40); characterized in that the aircraft (1) comprises an electrical energy storage system (30) electrically connected to the propulsion system (40) and providing fully electric propulsion of the aircraft (1).

2. Aircraft (1) according to claim 1, characterized in that the propulsion system (40) comprises: - a fairing (41); - a nozzle (42) disposed at the rear of the fairing (41) and centered on a nozzle axis (A42); - a drive shaft (43) disposed in the fairing (41) and centered on a drive shaft (A43); and - a shrouded propeller (44) mounted on the drive shaft (43) inside the fairing (41).

3. Aircraft (1) according to claim 2, characterized in that the nozzle axis (A42) is inclined with respect to the engine axis (A43), with an angle (c) formed between the nozzle axis (A42) and the engine axis (A43) which is between 1 and 30 degrees, for example equal to 20 degrees.

4. Aircraft (1) according to claim 3, characterized in that the nozzle axis (A42) is inclined upwards with respect to the engine axis (A43).

5. Aircraft (1) according to any one of claims 2 to 4, characterized in that in the lower part, the fairing (41) is integral with the central wing (10).

6. Aircraft (1) according to any one of claims 2 to 5, characterized in that it comprises a fin (50) mounted on the fairing (41).

7. Aircraft (1) according to any one of claims 2 to 6, characterized in that the propulsion system (40) comprises a rudder (60) positioned in the extension of the nozzle (42).

8. Aircraft (1) according to any one of the preceding claims, characterized in that the central wing (10) comprises a hollow area (16) formed in front of the propulsion system (40) for air intake and having a profile in tangency with the propulsion system (40).

9. Aircraft (1) according to any one of the preceding claims, characterized in that the propulsion system (40) is positioned on the central wing (10).

10. Aircraft (1) according to any one of the preceding claims, characterized in that it comprises two propulsion systems (40) mounted on the central wing (10), respectively to the left and right of a vertical central plane (Pxz) of the aircraft (1).

Images