Aircraft comprising at least one fluidic propulsion device integrated into a component of the airframe and method of use

Abstract

An aircraft (100) comprising an airframe including several airframe elements (101, 102, 103, 104) and at least one fluidic propulsion device (3) having a peripheral nozzle (30) defining an internal cavity (33) through which an external airflow (F1) circulates, the peripheral nozzle (30) having openings (32) configured to inject a plurality of high-speed airflows (F2) into the internal cavity (33) so as to accelerate the external airflow (F1) from upstream to downstream, a portion of the peripheral nozzle (30) being integrated into an airframe element (101, 102, 103, 104) so ​​as to allow the acceleration of an external airflow (F1) circulating from upstream to downstream over said airframe element (101, 102, 103, 104) so ​​as to improve its reattachment to said cell element (101, 102, 103, 104). Figure of the abstract: Figure 1

Description

Title of the invention: Aircraft comprising at least one fluid propulsion device integrated into an element of the cell and method of use Technical field

[0001] The present invention relates to the field of aircraft propulsion.

[0002] As is known, an aircraft comprises several propulsion devices comprising a rotating propulsion member such as a turbojet fan or a turboprop propeller in order to accelerate an airflow flowing from upstream to downstream.

[0003] During aircraft flight, an airflow circulates from upstream to downstream along elements of the aircraft's airframe such as a wing, a tailplane or a nacelle of a turbomachine, which generally induces turbulence which increases drag and / or affects lift. In order to eliminate this drawback, it has been proposed to modify the streamlined surface (adding ribs, etc.) to allow optimal reattachment of the boundary layer and improve lift.

[0004] These various solutions are not satisfactory and it is an objective of the present invention to improve the re-bonding of the boundary layer of streamlined surfaces.

[0005] Incidentally, in order to avoid damaging a rotating propulsion member and degrading the operation of a propulsion device during the ingestion of foreign bodies, it has been proposed to use a fluid propulsion device making it possible to accelerate an air flow circulating from upstream to downstream by injecting a high-speed air flow peripherally. A fluid propulsion device does not require a rotating propulsion member and is therefore not likely to be damaged in the event of ingestion, which is advantageous.

[0006] In order to achieve optimal propulsion, it has been proposed to mount a fluid propulsion device to an aircraft fuselage via a support arm / pylon so as to accelerate an upstream airflow undisturbed by the fuselage. PRESENTATION OF THE INVENTION

[0007] The invention relates to an aircraft comprising an airframe and several airframe elements and at least one fluid propulsion device configured to accelerate an external airflow circulating from upstream to downstream, the fluid propulsion device comprising a peripheral nozzle defining an interior cavity, free of obstacles, in which the external airflow circulates, the peripheral nozzle comprising openings configured to inject a plurality of high-speed airflows into the interior cavity so as to accelerate the external airflow from upstream to downstream.

[0008] The aircraft is remarkable in that a portion of the peripheral nozzle is integrated into a cell element so as to allow the acceleration of an external air flow circulating from upstream to downstream on said cell element so as to improve its reattachment to said cell element.

[0009] Thanks to the invention, one or more fluid propulsion devices can be used to allow local reattachments of the boundary layer which is subject to turbulence in the vicinity of a cell element. The resistance to forward movement (drag), the lift and the propulsion are improved. Advantageously, the risk of damage is low given that a fluid propulsion device does not comprise a rotating propulsion member.

[0010] Furthermore, the present invention makes it possible to counter a prejudice of the prior art which aimed to systematically remove a fluid propulsion device from a cell element (wing, fuselage, etc.) in order to avoid being disturbed by turbulence in the vicinity of a cell element.

[0011] Preferably, the interior cavity of the fluid propulsion device is delimited in part by a surface of said cell element. Thus, the boundary layer at the level of the aerodynamic structure of said cell element makes it possible to capture the boundary layer optimally to promote its reattachment.

[0012] Preferably, said cell element defines a lower intrados surface and an upper extrados surface. The fluid propulsion device is mounted on the upper extrados surface. This makes it possible to improve the lift or even the efficiency of the high-lift devices and / or flight controls.

[0013] According to one aspect of the invention, the cell element is chosen from a wing, a tail or a turbomachine nacelle. Integration into a nacelle makes it possible to take advantage of a high-speed airflow from the turbomachine.

[0014] Preferably, the fluid propulsion device extends vertically from said cell element. According to a preferred aspect, the fluid propulsion device has a flattened shape to promote the capture of the external air flow circulating from upstream to downstream on said cell element. This makes it possible to capture the boundary layer optimally to promote its reattachment.

[0015] Preferably, the fluid propulsion device is powered by a system for supplying a high-speed air flow, in particular, by a compression system of the aircraft. According to a preferred aspect, the power supply system is a traditional propulsion device comprising a rotating propulsion member. Thus, the fluid propulsion device makes it possible to provide additional propulsion to a traditional propulsion device.

[0016] Preferably, the supply system is configured to take an external air flow upstream of the fluid propulsion device to accelerate it in one high-speed airflow. Such upstream air sampling helps to promote the reattachment of the boundary layer and thus improve lift.

[0017] According to one aspect of the invention, the feed system comprises a plurality of scoop openings on said cell element which are configured to take an external air flow upstream of the fluid propulsion device to accelerate it into a high speed air flow. Preferably, the cell element comprises a porous skin to capture the external air flow over a large surface area to promote reattachment without inducing turbulence.

[0018] The invention also relates to a method of using an aircraft as presented previously comprising at least one fluid propulsion device of which a portion of the peripheral nozzle is integrated into a cell element, the method comprising at least one step consisting of injecting a plurality of high-speed air flows into the interior cavity of the fluid propulsion device so as to accelerate the external air flow circulating from upstream to downstream on said cell element. PRESENTATION OF FIGURES

[0019] The invention will be better understood on reading the description which follows, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0020] [Fig.l] is a partial schematic representation of an aircraft comprising a plurality of fluid propulsion devices integrated into elements of the wing and the horizontal stabilizer.

[0021] [Fig.2] is a schematic representation seen from upstream of a fluid propulsion device.

[0022] [Fig. 3] is a schematic representation in axial section of the integration of the fluid propulsion device integrated into a wing.

[0023] [Fig.4] is a schematic representation from above of the fluid propulsion device.

[0024] [Fig. 5] is a schematic representation in axial section of the integration of the fluid propulsion device integrated into a wing according to a second embodiment.

[0025] It should be noted that the figures set out the invention in detail for implementing the invention, said figures can of course be used to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0026] With reference to [Fig.l], the invention relates to an aircraft 100, in particular, a aircraft but the invention applies to other types of aircraft, in particular, a helicopter or a drone.

[0027] In a known manner, the aircraft 100 comprises a cell comprising several cell elements, for example, a nose cone, a main box, wings 101 and a tailplane 102. Among the cell elements, a nacelle 103 of a propulsion turbomachine 2 is also included. In this example, the cell elements are in contact with the external air flow F1 circulating from upstream to downstream along a longitudinal axis X oriented from downstream to upstream.

[0028] Still with reference to [Fig.l], the aircraft 100 comprises several fluid propulsion devices 3, in particular, distributed symmetrically on the aircraft 100. In this embodiment, fluid propulsion devices 3 have been presented integrated into a wing 101, into a tailplane 102, into a nacelle 103 and into a fuselage 104 but it goes without saying that fluid propulsion devices 3 could only be present on certain airframe elements. Similarly, a single or several fluid propulsion devices 3 can be mounted on the same airframe element in order to allow optimal reattachment of the external air flow as will be presented later depending on the geometry and positioning of the airframe element 101, 102, 103, 104. According to one aspect of the invention, the wing 101 can also have a rhomboidal shape.

[0029] A fluid propulsion device 3 integrated into a wing 101 will now be presented with reference to FIGS. 2 to 4. It nevertheless goes without saying that the invention applies in a similar manner to any cell element, a tailplane 102, a nacelle 103, a fuselage 104 or to another cell element of the aircraft such as the rear part of the fuselage, aerodynamic protrusions of a helicopter such as mini wings.

[0030] In this example, the wing 101 extends laterally and comprises a lower intrados surface 101 and an upper extrados surface 101e which are in contact with the external air flow F1 flowing from upstream to downstream along a longitudinal axis X. The external air flow F1 is likely to separate from the upper extrados surface 101e depending on the operating conditions, which affects the lift of the wing 101 and limits the propulsion performance. In practice, the separation occurs at the external air flow layer F1 which is closest to the wing 101 and whose speed is low. This layer is called the “boundary layer”. The same applies to all aerodynamic surfaces.

[0031] With reference to [Fig. 2], the fluid propulsion device 3 comprises a peripheral nozzle 30 defining an interior cavity 33, free of obstacles, in which the external air flow F1 circulates as illustrated in [Fig. 3]. The interior cavity 33 extends longitudinally along the axis X and is free of obstacles, which allows a foreign body to be ingested during the flight of the aircraft 100 without risk of damage. In other words, the fluid propulsion device 3 consists of a peripheral nozzle 30.

[0032] With reference to [Fig.2], the peripheral nozzle 30 has a hollow structure connected to a supply system 4 which makes it possible to supply a high pressure air flow F2 which will be presented later.

[0033] With reference to [Fig. 3], the peripheral nozzle 30 comprises openings 32 configured to inject a plurality of high-speed air flows F2 into the interior cavity 33 so as to accelerate the exterior air flow F1 from upstream to downstream. In other words, the exterior air flow F1 is considered to be a low-speed flow with respect to the high-speed air flow F2. The exterior air flow F1 and the high-speed air flow F2 are guided longitudinally in the interior cavity 33 so as to obtain at the outlet an accelerated air flow F3 which improves the reattachment while participating in the propulsion as illustrated in [Fig. 4].

[0034] The openings 32 are formed on an inner wall of the peripheral nozzle 30 so as to allow injection towards the inner cavity 33. Preferably, the openings 32 are positioned in an upstream portion of the peripheral nozzle 30 in order to be able to guide longitudinally downstream the external air flow F1 and the high-speed air flow F2 into the inner cavity 33. The incidence of the openings 32 is adapted to allow optimal acceleration while limiting turbulence. For example, a tangential or substantially tangential incidence is adapted. An angular deviation of less than 20° from the tangential direction is recommended.

[0035] The openings 32 may be in various forms, such as holes, slots, or others. The openings 32 are preferably distributed peripherally to ensure uniform acceleration of the air flow captured by the peripheral nozzle 30.

[0036] According to the invention, a portion of the peripheral nozzle 30 is integrated into the wing 101 so as to allow the acceleration of an external air flow F1 circulating from upstream to downstream on said wing 101 so as to improve its adhesion to said wing 101.

[0037] In other words, this makes it possible to capture the external air flow Fl in contact with the wing 101 which is likely, depending on the flight configuration, to detach by increasing the drag and / or reducing the lift to accelerate it in order, on the one hand, to reattach it and, on the other hand, to participate in the propulsion.

[0038] In this example, the fluid propulsion device 3 is mounted on the upper extrados surface 101e. Thus, as illustrated in FIGS. 2 and 3, the interior cavity 33 of the fluid propulsion device 3 is delimited in part by the upper extrados surface 101e of said wing 101. Thus, the external air flow F1 captured by the fluid propulsion device 3 is that which has been guided by the upper surface 101st extrados and which has a low speed.

[0039] The lower part of the peripheral nozzle 30 is therefore adapted to the shape of the upper extrados surface 101e in order to be integrated therein. The upper part of the peripheral nozzle 30, which projects from the upper extrados surface 101e, preferably has a flattened shape so as to reduce drag as much as possible. For the peripheral nozzle 30, a cross-section is defined relative to the longitudinal axis X which comprises a length extending parallel to the surface of the cell element and a height which extends perpendicular to said length. By flattened shape, we mean a peripheral nozzle 30 whose cross-section comprises a length greater than its height, preferably at least twice as great. The peripheral nozzle 30 thus captures mainly the layer of the external air flow F1 which is close to the wing 101.

[0040] The hollow wall of the peripheral nozzle 30 has a thickness which is calibrated so as to allow sufficient supply of the openings 32 while limiting the drag. The upper extrados surface 101e of the wing 101 thus comprises a supply cavity 301 for high-speed air flow F2 which comprises openings 32 for injecting high-speed air flows F2 into the interior cavity 33.

[0041] The peripheral nozzle 30 is supplied with high-speed air F2 via a supply system 4 of the aircraft 100 which may take various forms. Preferably, the aircraft 100 comprises a compressor which takes an external air flow F1 to accelerate it and supply the peripheral nozzle 30. Preferably, when the aircraft comprises a propulsion device comprising a rotating propulsion member, hereinafter referred to as “conventional propulsion device 2”, it is the latter which fulfills the function of supplying high-speed air flow F2.

[0042] With reference to [Fig. 2], the supply system 4 is connected to the peripheral nozzle 30 by a pneumatic circuit 40 whose length is optimized to limit its mass. The use of a traditional propulsion device 2 as the supply system 4 makes it possible to position one or more fluid propulsion devices 3 near a traditional propulsion device 2 while limiting the length of the pneumatic circuit 40. In the case of a nacelle 103 surrounding a traditional propulsion device 2 and equipped with a fluid propulsion device 3, the length of the pneumatic circuit 40 is very short.

[0043] Preferably, the traditional propulsion device 2 may be in the form of a turbomachine (turbojet, turboprop, etc.), an electric motor or other.

[0044] According to a preferred aspect, the supply system 4 is configured to take an external air flow F1 at the level of the cell element 101, 102, 103 in particular upstream of the fluid propulsion device 3.

[0045] According to one embodiment, with reference to [Fig. 5], the supply system 4 comprises at least one scoop opening 41 formed in the upper extrados surface 101e aligned longitudinally with the fluid propulsion device 3 so as to suck in the external air flow F1 upstream of the fluid propulsion device 3 and limit separation. Such a configuration is advantageous from an aerodynamic point of view and improves lift. According to a preferred aspect, the upper extrados surface 101e comprises a plurality of scoop openings 41 so as to form a porous skin upstream of the fluid propulsion device 3 as illustrated in [Fig. 5]. The supply system 4 thus makes it possible to suck in an external air flow F1 to inject it into the fluid propulsion device 3 after acceleration.

[0046] According to one aspect of the invention, the aircraft 100 comprises, on the one hand, at least one propulsion device comprising a rotating propulsion member, hereinafter referred to as “conventional propulsion device 2”, to provide propulsion for the aircraft 100 and, on the other hand, at least one fluid propulsion device 3 to enable local reattachment of the external air flow F1 to a cell element 101, 102, 103, 104 while enabling participation in the propulsion. Thus, according to this aspect of the invention, the fluid propulsion device(s) 3 enable supplementary propulsion to be provided in parallel with the traditional propulsion device(s) 2.

[0047] The traditional propulsion device 2 may be in the form of a turbomachine connected to a wing, a power generator mounted at the rear of the fuselage, a power generator mounted at the root of a wing or other.

[0048] In such a case, the high-speed air flow F2 of the fluid propulsion device(s) 3 can be supplied directly by one or more traditional propulsion devices 2 which then fulfill the role of the supply system 4. It goes without saying that the high-speed air flow F2 supply system 4 can also be independent of the traditional propulsion device(s) 2.

[0049] According to another aspect of the invention, the aircraft 100 comprises only one or more fluid propulsion devices 3 to allow local reattachment of the external air flow F1 to a cell element 101, 102, 103, 104 and allow propulsion. Thus, according to this aspect of the invention, the fluid propulsion device(s) 3 alone allow propulsion to be provided.

[0050] A method of using an aircraft 100 will now be presented with reference to [Fig. 2]. The method of use comprises at least one step consisting of injecting a plurality of high-speed air flows F2 into the interior cavity 33 of the fluid propulsion device 3 so as to accelerate the external air flow F1 circulating from upstream to downstream on said cell element 101 so as to obtain an accelerated air flow F3 which is reattached and participates in reducing the drag and / or the lift. and propulsion.

[0051] Preferably, the method also comprises a step consisting of taking an external air flow F1 upstream of the fluid propulsion device 3, in particular, via a porous wall of the cell element 101. Preferably, the high-speed air flow F2 is obtained by accelerating the external air flow F1 by the traditional propulsion device 2.

[0052] Thanks to the invention, the turbulence at the level of the elements of the cell is reduced locally thanks to the use of a plurality of fluid propulsion devices 3 which make it possible to improve the lift and to participate in the propulsion. The invention has been presented for an aircraft with a pilot but the invention also applies to an aircraft without a pilot called a "drone".

Claims

Claims

1. An aircraft (100) comprising a cell comprising a plurality of cell elements (101, 102, 103, 104) and at least one fluid propulsion device (3) configured to accelerate an external air flow (F1) flowing from upstream to downstream, the fluid propulsion device (3) comprising a peripheral nozzle (30) defining an interior cavity (33), free of obstacles, in which the external air flow (F1) circulates, the peripheral nozzle (30) comprising openings (32) configured to inject a plurality of high-speed air flows (F2) into the interior cavity (33) so as to accelerate the external air flow (F1) from upstream to downstream, a portion of the peripheral nozzle (30) being integrated into a cell element (101, 102, 103, 104) so as to allow acceleration of an external air flow (Fl) circulating from upstream to downstream on said cell element (101, 102, 103,104) so as to improve its reattachment to said cell element (101, 102, 103, 104), the fluid propulsion device (3) being supplied by a supply system (4) with a high-speed air flow (F2), aircraft (100) characterized in that the supply system (4) comprises a plurality of scoop openings (41) on said cell element (101, 102, 103, 104) configured to take an external air flow (F1) upstream of the fluid propulsion device (3) to accelerate it into a high-speed air flow (F2).,

2. Aircraft (100) according to claim 1, wherein the interior cavity (33) of the fluid propulsion device (3) is delimited in part by a surface of said cell element (101, 102, 103, 104).

3. Aircraft (100) according to one of claims 1 to 2, wherein said cell element (101, 102, 103, 104) defining a lower intrados surface (101i) and an upper extrados surface (101e), the fluid propulsion device (3) is mounted on the upper extrados surface (101e).

4. Aircraft (100) according to one of claims 1 to 3, in which the cell element (101, 102, 103, 104) is chosen from a wing, a tail or a turbomachine nacelle.

5. Aircraft (100) according to one of claims 1 to 4, wherein the fluid propulsion device (3) extends in vertical projection from said airframe element (101, 102, 103, 104).

6. Aircraft (100) according to one of claims 1 to 5, in which the fluid propulsion device (3) has a flattened shape to promote the capture of the external air flow (Fl) circulating from upstream to downstream on said cell element (101, 102, 103, 104).

7. Aircraft (100) according to one of claims 1 to 6, in which the fluid propulsion device (3) is powered by a compression system of the aircraft.

8. Method of using an aircraft (100) according to one of the claims previous ones comprising at least one fluid propulsion device (3) of which a portion of the peripheral nozzle (30) is integrated into a cell element (101, 102, 103, 104), the method comprising a step of injecting a plurality of high-speed air flows (F2) into the interior cavity (33) of the fluid propulsion device (3) so as to accelerate the exterior air flow (F1) circulating from upstream to downstream on said cell element (101, 102, 103).

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