Foldable trailing edge flying wing unmanned aerial vehicle
By designing a foldable trailing edge flying wing drone, the active rotation shaft drives the winglets, wings and tails to fold, forming a wing layout, solving the poor handling performance of the flying wing drone during low-speed flight and complex maneuvering operations. and the problem of low critical velocity of flutter has achieved higher aerodynamic efficiency, maneuverability and high-speed flutter speed.
Patent Information
- Application Number
- CN202421354534.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2025-02-11
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing flying wing drones have poor handling performance when flying at low speeds and performing complex maneuvering operations. The lack of a vertical tail leads to insufficient stability, and the critical velocity of flutter under high-speed flat flight is low.
A foldable trailing edge flying wing drone is designed to fold the winglets, joints and tails through the active rotation shaft to form a joint layout, which increases the stability surface and reduces the wingtip vortex intensity.
Maintain high aerodynamic efficiency in cruise states and improve range; provide additional torque and stability when performing complex maneuvering operations to improve maneuverability; increase critical velocity of flutter during high-speed flight.
Smart Images
Figure CN222452576U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of unmanned aerial vehicles, in particular to a flying wing unmanned aerial vehicle with foldable trailing edge. Background Art
[0002] Flying wing layout UAVs use wing-body fusion technology and usually eliminate the tail. This approach aims to minimize adverse aerodynamic interactions and radar cross-section, thereby significantly improving their aerodynamic performance and stealth capabilities.
[0003] However, in low-speed flight conditions, due to the lack of stability contribution from the vertical tail, it is easier to lose balance, resulting in insufficient lift or directional instability, making the flying wing UAV prone to stalling or loss of control. When performing complex maneuvers such as emergency avoidance, high angle climb, and small radius turn, due to the lack of additional control surfaces, it faces problems such as poor maneuverability, small effective angle of attack range, large turning radius, and long reaction time. Utility Model Content
[0004] The utility model provides a flying wing UAV with a foldable trailing edge, which solves the control performance problems of the existing flying wing UAV when flying at low speed and performing complex maneuvers, and effectively improves the flutter critical speed under high-speed level flight.
[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0006] A foldable trailing edge flying wing UAV comprises a main wing, wherein the main wing comprises an inner section and an outer section, the wingtip of the outer section is connected to a winglet, and the trailing edge of the outer section is connected to a connecting wing and a tail wing; the winglet is connected to the connecting wing through an active rotating shaft, the connecting wing is connected to the tail wing through a passive hinge, and the tail wing is connected to the inner section of the main wing through a passive hinge; the front of the connecting wing and the tail wing is connected to the outer section of the main wing through a locking structure.
[0007] Furthermore, the connecting wing and the tail wing are equal in length in the incoming flow direction, and the length is one third of the chord length of the wing tip of the flying wing.
[0008] Furthermore, the direction of each passive hinge is the same as the incoming flow direction.
[0009] Furthermore, the drone has a flying wing layout when stretched, with a wingspan of 1.7m and a wing area of 0.5m 2 The chord length of the symmetry surface is 0.6m, the chord length at the inflection point of the leading edge of the flying wing is 0.3m, and the chord length of the wingtip is 0.22m.
[0010] Furthermore, the sweep angle of the leading edge of the inner section of the main wing is 60°, and the sweep angle of the leading edge of the outer section of the main wing and the winglet is 16°.
[0011] Furthermore, the drone has a connected-wing layout when folded, with a winglet length of 0.13m, a connected-wing length of 0.5m, and a tail length of 0.2m.
[0012] Furthermore, the maximum folding angle of the tail wing is 98°, and the maximum folding angle of the winglet is 162°.
[0013] The beneficial effects of the utility model are:
[0014] The utility model maintains the stretched shape of the flying wing layout in a cruising state, can obtain higher aerodynamic efficiency, and achieve a higher range.
[0015] When performing complex maneuvers such as emergency avoidance, high angle of attack climb, and small radius turn, the utility model folds the winglets, connecting wings, and tail wings under the drive of the wingtip active shaft to form a connected wing layout. These wing surfaces are converted from being on the same plane to a three-dimensional structure, adding additional stabilizers to the flying wing drone while providing additional torque for the drone to perform complex maneuvers. In addition, the wingtip vortex intensity can be reduced, thereby reducing the induced drag of the drone.
[0016] When the utility model flies at high speed, the unmanned aerial vehicle is converted into a linked wing layout so that the unmanned aerial vehicle can have a higher flutter speed. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0018] Figure 1 It is a three-dimensional diagram of the utility model under the flying wing layout.
[0019] Figure 2 This is the front view of the utility model under the flying wing layout.
[0020] Figure 3 It is a side view of the utility model under the flying wing layout.
[0021] Figure 4 It is a top view of the utility model under the flying wing layout.
[0022] Figure 5 It is a three-dimensional diagram of the utility model under the wing-connected layout.
[0023] Figure 6 This is the front view of the utility model under the wing-connected layout.
[0024] Figure 7It is a side view of the utility model under the wing-connected layout.
[0025] Figure 8 It is a top view of the utility model under the wing-connected layout.
[0026] Fig. 9 The variation of flutter velocity with the tail folding angle under different hinge stiffness.
[0027] Fig.10 The variation of flutter frequency with the tail folding angle under different hinge stiffness.
[0028] Description of Figure Numbers:
[0029] 1. Inner section of the main wing; 2. Outer section of the main wing; 3. Winglet; 4. Connecting wing; 5. Tail wing; 6. Active shaft; 7. Passive hinge. DETAILED DESCRIPTION
[0030] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.
[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.
[0033] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values do not limit the scope of the utility model. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.
[0034] In the description of the present utility model, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present utility model and simplifying the description. Unless otherwise stated, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present utility model: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.
[0035] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0036] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the utility model.
[0037] The utility model provides a technical solution: a foldable trailing edge flying wing drone, such as Figure 1-10 As shown, it includes a main wing (an inner section 1 of the main wing, an outer section 2 of the main wing), a winglet 3, a connecting wing 4, a tail 5, an active shaft 6, and a passive hinge 7. The aircraft is in a double-swept flying wing layout in the extended state, the leading edge sweep angle of the inner section 1 of the main wing is 60°, and the leading edge sweep angles of the outer section 2 of the main wing and the winglet 3 are 16°.
[0038] The foldable trailing edge flying wing UAV can realize the translation and rotation of the winglet 3, the connecting wing 4, and the tail wing 5 relative to the main wing by driving the wingtip active rotating shaft 6 to form a connected wing layout. The winglet 3 is the leading edge of the wingtip of the outer section 2 of the main wing of the flying wing, and the connecting wing 4 and the tail wing 5 are the trailing edge of the outer section 2 of the main wing of the flying wing.
[0039] The main wing includes the inner section of the flying wing and the leading edge of the outer section except the wing tip, which is fixed during the folding process and accounts for 71% of the total wing area.
[0040] The winglet 3 is the leading edge of the wingtip of the outer section of the flying wing, with a length of 130 mm in the wingspan direction. The end close to the symmetry plane of the flying wing is connected to the main wing using a passive hinge 7 in the same direction as the incoming flow, and the wingtip end is connected to the wingtip end of the connecting wing 4 using an active rotating shaft 6.
[0041] The connecting wing 4 is a part of the trailing edge of the outer section of the flying wing, with a length of 500 mm in the span direction and a uniform width in the incoming flow direction, the width of which is 1 / 3 of the chord length of the wing tip of the flying wing. The end close to the symmetry plane of the flying wing is connected to the tail 5 using a passive hinge 7 in the same direction as the incoming flow, and the wing tip end is connected to the wing tip end of the winglet 3 using an active shaft 6, and its leading edge has a fillet with a radius of 5 mm to reduce the resistance after folding.
[0042] The winglet 3 is a part of the trailing edge of the outer section of the original flying wing, with a length of 200 mm in the span direction and a uniform width in the incoming flow direction, the width of which is 1 / 3 of the chord length of the wing tip of the flying wing. The end close to the symmetry plane of the flying wing is connected to the outer trailing edge of the inner section 1 of the main wing by a passive hinge 7 in the same direction as the incoming flow, and the end close to the wing tip is connected to the end of the connecting wing 4 close to the symmetry plane by a passive hinge 7, and its leading edge has a fillet with a radius of 5 mm to reduce the resistance after folding.
[0043] The active rotating shaft 6 is located at the wing tip of the flying wing and is wrapped with a fairing. Its power comes from the stepper motor inside the winglet 3.
[0044] The passive hinge 7 has three locations in the drone, which are used to connect the main wing outer section 2 and the winglet 3, the main wing inner section 1 and the tail 5, and the tail 5 and the connecting wing 4. The passive hinge 7 has two states: locked and unlocked, and the hinge stiffness in the locked state can be selected.
[0045] The passive hinge 7 may have optional stiffnesses of 50 N*m / rad, 100 N*m / rad, 150 N*m / rad, 250 N*m / rad, and 300 N*m / rad. Selecting different hinge stiffnesses can control the critical flutter speed of the drone.
[0046] The linked wing aircraft has a diamond-shaped structure in both the front view and the top view, and has the advantages of light weight, high rigidity, low induced drag, good stability and controllability, and direct lift and side force control. By folding the trailing edge to make the flying wing layout into a linked wing 4 layout, the overall rigidity level of the UAV can be improved. By folding the tail 5 to different degrees and setting appropriate rigidity for each hinge, the flutter critical speed of the UAV during high-speed flight can be increased.
[0047] Example 1
[0048] like Figure 1-10 As shown, a novel foldable trailing edge flying wing UAV, its important components include main wing, left and right winglets 3, left and right connecting wings 4, left and right tail wings 5, left and right active shafts 6, six groups of passive hinges 7, power device, flight controller, fixing pins, etc. Among them, the winglets 3, connecting wings 4 and tail wings 5 are foldable components, the winglets 3 are connected to the main wing through the passive hinges 7, connected to the connecting wings 4 through the active shafts 6, and the tail wings 5 are connected to the main wing and the connecting wings 4 through the passive hinges 7 at both ends.
[0049] The main wing of the novel foldable trailing edge flying wing UAV has an airfoil of NACA65019 on the symmetry plane, with a chord length of 600 mm, an airfoil of the junction section between the inner section 1 of the main wing and the outer section is a NACA0008 symmetrical airfoil, and the inner section 1 of the main wing is a lofted transition between the NACA65019 airfoil and the NACA0008 airfoil; the portion between the above section and the wing tip surface is a NACA0008 symmetrical airfoil.
[0050] The leading edge of the UAV adopts a double-sweep design, and the leading edge sweep angles of the main wing inner section 1 and the main wing outer section 2 are 60° and 16° respectively. The leading edge of the outer wing of the flying wing is divided along the incoming flow direction at a position 130mm away from the wing tip, and the section close to the wing tip is defined as a winglet 3; the trailing edge of the outer wing can be disconnected within a range of equal width in the incoming flow direction, and its width is 1 / 3 of the chord length of the wing tip, dividing the tail 5 and the connecting wing 4, and the lengths of the winglet 3 and the connecting wing 4 in the wingspan direction are 200mm and 500mm respectively.
[0051] The leading edges of the connecting wing 4 and the tail wing 5 have a 5mm fillet to prevent the phenomenon that the windward surface of the leading edges of the two wings is flat due to segmentation, resulting in excessive resistance. The main wing outer section 2 and the winglet 3 can be provided with a rectifying tip on the lower wing surface at the junction with the connecting wing 4 and the tail wing 5. On the one hand, a limit is set for the connecting wing 4 and the tail wing 5 of the drone in the stretched state to prevent the tail wing 5 and the winglet 3 from shifting downward under the action of gravity. On the other hand, it has a rectifying effect, reducing the impact of the gap caused by the fillet of the leading edge of the connecting wing 4 and the tail wing 5 on the aerodynamic efficiency.
[0052] The winglet 3 and the tail 5 are defined as rotating around the passive hinge 7, and the angle at which the wing surface deviates from the stretched state is defined as the folding angle. In terms of geometric relationship, the winglet 3 and the tail 5 of the foldable trailing edge flying wing UAV have a limiting angle. At the limiting folding angle, the winglet 3 and the connecting wing 4 are coplanar. At this time, when the UAV is observed along the incoming flow direction, the plane where the main wing outer section 2, the tail 5 and the connecting wing 4 are located together with the winglet 3 forms an obtuse triangle structure. At the limiting folding angle, the folding angle of the tail 5 is 98°, and the folding angle of the winglet 3 is 162°. At this time, the lower reverse angle of the connecting wing 4 is 18°.
[0053] When the UAV is flying, when it has higher requirements for flight speed and maneuverability than level flight cruising, the conventional flying wing layout is difficult to meet its needs. Driven by the wingtip active shaft 6, the UAV folds the trailing edge and the winglet 3 to form a connected wing layout. The layout has the advantages of stronger maneuverability, higher rigidity, lower induced drag, and higher flutter speed. It has higher environmental adaptability under conditions such as high-speed flight, emergency avoidance, high angle of attack climb, and small radius turn.
[0054] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed by the present invention according to the technical solution and inventive concept of the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A foldable trailing edge flying wing drone, characterized in that: The invention comprises a main wing, wherein the main wing comprises a main wing inner section (1) and a main wing outer section (2); the wing tip of the main wing outer section (2) is connected to a winglet (3); the trailing edge of the main wing outer section (2) is connected to a connecting wing (4) and a tail wing (5); the winglet (3) is connected to the connecting wing (4) through an active rotating shaft (6); the connecting wing (4) is connected to the tail wing (5) through a passive hinge (7); the tail wing (5) is connected to the main wing inner section (1) through a passive hinge (7); the front of the connecting wing (4) and the tail wing (5) is connected to the main wing outer section (2) through a locking structure.
2. The foldable trailing edge flying wing drone according to claim 1, characterized in that: The connecting wing (4) and the tail wing (5) are of equal length in the incoming flow direction, and the length is one third of the chord length of the wing tip of the flying wing.
3. The foldable trailing edge flying wing drone according to claim 1, characterized in that: The direction of each passive hinge (7) is the same as the incoming flow direction.
4. The foldable trailing edge flying wing UAV according to claim 1, characterized in that: The drone has a flying wing layout when in extended state, with a wingspan of 1.7m and a wing area of 0.5m 2 The chord length of the symmetry surface is 0.6m, the chord length at the inflection point of the leading edge of the flying wing is 0.3m, and the chord length of the wingtip is 0.22m.
5. The foldable trailing edge flying wing drone according to claim 4, characterized in that: The leading edge sweep angle of the main wing inner section (1) is 60°, and the leading edge sweep angles of the main wing outer section (2) and the winglet (3) are 16°.
6. The foldable trailing edge flying wing drone according to claim 1, characterized in that: The drone has a wing-jointed layout when in the folded state, with the winglet (3) being 0.13 m long, the wing-jointed (4) being 0.5 m long, and the tail (5) being 0.2 m long.
7. The foldable trailing edge flying wing UAV according to claim 6, characterized in that: The maximum folding angle of the tail wing (5) is 98°, and the maximum folding angle of the winglet (3) is 162°.