Flexible wingtip and wing and aircraft comprising same

Abstract

The invention provides a flexible wingtip, a wing comprising the flexible wingtip and an aircraft, the flexible wingtip comprises a shell and a hollow structure located in the shell, the shell and the hollow structure are both made of a flexible high polymer material, and the cross section of the flexible wingtip is streamlined.

Description

Technical Field

[0001] This application belongs to the field of aircraft, and particularly relates to a flexible wing and an aircraft including the same. Background Technology

[0002] The background description provided herein serves to give a general overview of the background of this application. The work of the currently identified inventors to the extent described in this background section, and aspects of this description that do not constitute prior art at the time of application, are neither expressly nor impliedly acknowledged as prior art in conflict with this application.

[0003] Fixed-wing aircraft, such as manned aircraft or drones, typically rely on the pressure difference created by airflow over the upper and lower surfaces of the wing to generate upward lift. When the lift exceeds the aircraft's weight, it can take off or climb. During flight, the high-pressure airflow on the lower surface of the wing flows around the wingtip to the upper surface, forming vortices known as wingtip vortices. The intensity of these vortices increases with the aircraft's speed. Wingtip vortices contribute to drag, increase energy consumption, and in severe cases, can cause safety accidents.

[0004] In existing technologies, wingtip vortex problems are solved by adding winglets to aircraft. The winglets, tilted upwards relative to the wing body, can readjust the wingtip vortices, moving them further away from the outer edge of the wing and upwards into laminar flow, thus effectively reducing drag and fuel consumption during flight. For example, Chinese patent CN108177761A discloses a fully composite material winglet suitable for high aspect ratio wings. The winglet includes a skin, a foam core, edge sealing ribs, and a cylindrical tube. The skin has a cylindrical cavity structure, the foam core is placed inside the cavity, and the edge sealing ribs are placed at the edge of the cavity. The cylindrical tube is placed inside the foam core, with one end connected to an opening on the outer side of the skin and the other end connected to an opening on the edge sealing rib. A navigation light is installed at the opening on the outer side of the skin and connected to the cylindrical tube. The navigation light's wiring passes through the cylindrical tube, through the opening on the edge sealing rib, and leads to the main wing surface. However, adding winglets increases the weight of the aircraft, raises maintenance costs, and in some cases, increases wing flutter and the risk of collisions. This makes the disadvantages of winglets outweigh the advantages for low-speed, short-duration flight missions.

[0005] Furthermore, 3D printing technology is increasingly being used in aircraft manufacturing, especially in drone manufacturing. Wings generated by 3D printing are typically printed from the wing root to the wingtip, resulting in lower strength at the wingtip. Additionally, due to the lower flexibility of the printing material used, the wingtip is prone to breakage when subjected to air pressure perpendicular to its extension direction.

[0006] Therefore, a new wingtip is needed. Summary of the Invention

[0007] This section presents the selection of inventive concepts in a simplified form, which will be further illustrated in the detailed description below. This section is not intended to identify key or essential features of the claimed subject matter, nor is it intended to assist in determining the scope of the claimed subject matter.

[0008] In view of the problems existing in the prior art, this application provides a flexible wingtip, wherein the flexible wingtip includes a shell and a hollow structure located inside the shell, both of which are made of flexible polymer material, and the cross-section of the flexible wingtip is streamlined.

[0009] Preferably, the hollow structure includes an array of hollow prisms that extend along the length of the flexible wingtip.

[0010] Preferably, the hollow prism is selected from hollow triangular prisms, hollow quadrangular prisms, hollow pentagonal prisms, and hollow hexagonal prisms.

[0011] Preferably, the flexible polymer material is at least one of TPU, TPC, TPA, TPE or silicone.

[0012] Preferably, the shell and the hollow structure are made of the same flexible polymer material or different flexible polymer materials.

[0013] Preferably, the hollow structure is less flexible than the shell.

[0014] Preferably, the hollow structure includes a mounting hole that extends along the length of the flexible wingtip, and the cross-section of the mounting hole is circular and / or rectangular.

[0015] Preferably, the length of the mounting hole is within 1 / 2 of the length of the flexible wingtip.

[0016] Preferably, the mounting holes are positioned close to the housing of the flexible wingtip.

[0017] Preferably, the flexible wingtip is made by 3D printing.

[0018] In another aspect of this application, a wing is also provided, which includes a wing body and a flexible wingtip of this application, and the wing body is connected to the flexible wingtip by a rod.

[0019] Preferably, the wing body and flexible wingtip are integrally formed by 3D printing, wherein the wing body is printed from a rigid material.

[0020] Preferably, the wing body and the flexible wingtip are formed separately.

[0021] In another aspect of this application, an aircraft is also provided, which includes the wings of this application. Attached Figure Description

[0022] Other or additional features, advantages, and details are presented by way of example only in the following detailed description of the embodiments. In the accompanying drawings:

[0023] Appendix Figure 1 The flexible wingtip of this application and the wing including the flexible wingtip are schematically shown;

[0024] Appendix Figure 2 The cross-section of the flexible wingtip is shown schematically;

[0025] Appendix Figure 3 The schematic diagram illustrates an array of hollow prisms at the flexible wingtip; and

[0026] Appendix Figure 4 The illustration schematically shows a comparison of the vortex effects created by aircraft without flexible wingtips and those equipped with flexible wingtips. Detailed Implementation

[0027] The following description is exemplary in nature and is not intended to limit this application, application, or use. Furthermore, it is not intended to be limited by any express or implied theory presented in the foregoing technical field, background art, summary of the invention, or the following detailed description. It should be understood that throughout the drawings, corresponding reference numerals identify similar or corresponding parts or features.

[0028] This application will now be further elaborated. In the following paragraphs, different aspects of this application are defined in more detail. Unless expressly indicated to the contrary, each aspect so defined may be combined with any other aspect(s). In particular, any feature indicated as preferred or advantageous may be combined with any other feature(s) indicated as preferred or advantageous.

[0029] To address the problems in the prior art, this application provides a flexible wingtip. (See attached diagram.) Figure 1 and attached Figure 2 The flexible wingtip 100 according to the principles of this application includes a shell 110 and a perforated structure 120 located inside the shell. Both the shell 110 and the perforated structure 120 can be made of flexible polymer materials. Those skilled in the art will readily understand that flexible polymer materials are polymer materials with good flexibility and plasticity. The perforated structure 120 can reduce the overall weight of the flexible wingtip 100, which is beneficial for reducing energy consumption, and also helps to increase the deformation of the flexible wingtip 100, making it easier for the flexible wingtip 100 to bend under external forces, thus giving the flexible wingtip good deformability. Advantageously, the cross-section of the flexible wingtip 100 is streamlined to reduce flight drag.

[0030] See attached document Figure 2 and attached Figure 3 The hollow structure 120 includes an array of hollow prisms 121, which extend along the length of the flexible wingtip 100, making it easy to bend when subjected to a force perpendicular to it and possessing good shape recovery capability. The hollow prisms 121 can be selected from hollow triangular prisms, hollow quadrangular prisms, hollow pentagonal prisms, hollow hexagonal prisms, or prisms with more than six edges; this application does not impose any limitation on this. In some embodiments, the hollow prisms 121 are preferably triangular or quadrangular prisms. In some embodiments, the hollow prisms 121 are preferably hollow hexagonal prisms, making the cross-section of the hollow array honeycomb-like, thereby giving the flexible wingtip 100 both sufficient toughness and sufficient strength. It should be understood that the cross-sections of the hollow prisms in this application can have the same size or different sizes, and the density of the hollow array can be set according to the specific application scenario. Alternatively, in some embodiments, the hollow structure 120 may include a hollow cylindrical array composed of multiple cylinders, or a hollow elliptical cylindrical array composed of multiple hollow elliptical cylinders.

[0031] See attached document Figure 2 The perforated structure 120 may also include mounting holes extending along the length of the flexible wingtip 100 to connect the flexible wingtip 100 to the wing body via rods. The mounting holes can be circular mounting holes 122 with a circular cross-section or rectangular mounting holes 123 with a rectangular cross-section to mate with rods having different cross-sections. It should be understood that a circular cross-section includes cases with a regular circular cross-section and cases with a generally circular cross-section, and a rectangular cross-section includes cases with a regular rectangular cross-section or cases with a generally rectangular cross-section. Advantageously, the length of the mounting hole is within 1 / 2 of the length of the flexible wingtip 100, for example, between 1 / 3 and 1 / 2, or between 1 / 5 and 1 / 4, to ensure sufficient connection strength between the flexible wingtip 100 and the wing body, and to avoid affecting the flexibility of the flexible wingtip 100 due to excessive insertion of the connecting rod into the flexible wingtip 100.

[0032] See attached document Figure 2 Advantageously, the mounting hole is positioned flush against the housing 110, which eliminates any openwork between the mounting hole and the housing 110 near the edge of the housing 110. This enhances the connection strength between the mounting hole and the housing 110, preventing the mounting hole from cracking or detaching under heavy stress. Furthermore, the flush positioning of the mounting hole against the housing 110 also allows inserted rods to enhance the tensile or compressive strength of the housing at the mounting hole location.

[0033] Advantageously, the flexible polymer material according to the principles of this application is at least one of TPU (thermoplastic polyurethane), TPC (thermoplastic copolyester), TPA (thermoplastic polyamide), TPE (thermoplastic elastomer), or silicone. This allows the flexible wingtip 100 to have good flexibility and can also be manufactured by 3D printing. It should be understood that the shell 110 and the hollow structure 120 can be made of the same flexible polymer material or different flexible polymer materials as needed. In some embodiments, the shell 110 and the hollow structure 120 are made of different flexible polymer materials, and the flexible polymer material used to make the hollow structure 120 is less flexible than the flexible polymer material used to make the shell 110. That is, the hollow structure 120 is less flexible than the shell 110 to avoid excessive deformation of the flexible wingtip 100, so that the deformation of the flexible wingtip 100 can be kept within a reasonable range.

[0034] Advantageously, the flexible wingtip 100 according to the principles of this application is manufactured by 3D printing, thereby avoiding the problems of complex processing steps and low material utilization of traditional processing methods such as injection molding, and reducing processing errors. During the 3D printing process, the printing direction is along the length of the flexible wingtip 100 to facilitate the formation of the hollow structure 120 and ensure the printing quality of the shell.

[0035] See attached document Figure 1 This application also provides a wing, comprising a flexible wingtip 100 and a wing body 200 according to the principles of this application. The wing body 200 may be provided with mounting holes corresponding to the flexible wingtip 100 for inserting connecting rods. The flexible wingtip 100 can be connected to the wing body 200 via the rods to enhance the connection strength. Those skilled in the art will readily understand that the flexible wingtip 100 and the wing body 200 can be integrally formed or separately formed. In both integral and separate forming cases, the flexible wingtip 100 and the wing body 200 can be connected via rods. In some embodiments, the flexible wingtip 100 and the wing body 200 are separately formed, and the flexible wingtip 100 and the wing body 200 can be manufactured separately by 3D printing. In some embodiments, the flexible wingtip 100 and the wing body 200 are integrally formed by 3D printing, and the wing body 200 is printed from a rigid material such as ABS (acrylonitrile-styrene-butadiene copolymer). Advantageously, the rod can pass through the mounting hole of the flexible wingtip 100, through the mounting hole of the wing body 200, and extend towards the root of the wing body 200, so that the wing can be connected to the fuselage via the rod. Advantageously, the rod can be fixed to the mounting hole with adhesive to enhance the connection strength.

[0036] This application also provides an aircraft, which includes a wing according to the principles of this application. The aircraft can be a manned aircraft, an unmanned aircraft, or a drone. Those skilled in the art will readily understand that in the aircraft according to this application, the flexible wingtip can be straight or upturned or slightly upturned, like winglets in the prior art. At low speeds, the vortices are small, and the deformation of the flexible wingtip is minimal, having little impact. However, at higher speeds, the vortices increase, and the flexible wingtip deforms under the influence of the vortices, functioning as a winglet and reducing drag.

[0037] See attached document Figure 4 This diagram illustrates a comparison of the vortex effects generated by an aircraft equipped with flexible wingtips according to this application and by existing aircraft without flexible wingtips. When the pressure difference between the upper and lower surfaces of the aircraft's wing is large, the resulting wingtip vortices are larger. At this time, the flexible wingtips tilt upwards under the influence of air pressure, acting as winglets. Compared to aircraft without flexible wingtips, aircraft equipped with flexible wingtips not only avoid damage to the wingtips from wingtip vortices but also adjust the direction of the wingtip vortices, causing them to move away from the outer edge of the wing and rise above the laminar flow, reducing the intensity of the wingtip vortices and thus effectively reducing drag and energy consumption during flight.

[0038] While at least one exemplary embodiment has been described in the foregoing detailed description, it should be understood that numerous variations exist. It should also be understood that the one or more exemplary embodiments described herein are merely examples and are not intended to limit the scope, applicability, or construction of this application in any way. Rather, the foregoing detailed description will provide convenient guidance to those skilled in the art in implementing one or more exemplary embodiments. It should be understood that various changes, modifications, or alterations can be made to the function and arrangement of elements without departing from the scope of this application as set forth by the appended claims and their equivalents.

Claims

1. A flexible wingtip, characterized in that, The flexible wingtip includes a shell and a hollow structure located inside the shell. Both the shell and the hollow structure are made of flexible polymer material, and the cross-section of the flexible wingtip is streamlined.

2. The flexible wingtip as described in claim 1, characterized in that, The hollow structure includes an array of hollow prisms, which extend along the length of the flexible wingtip.

3. The flexible wingtip as described in claim 2, characterized in that, The hollow prism is selected from hollow triangular prisms, hollow square prisms, hollow pentagonal prisms, and hollow hexagonal prisms.

4. The flexible wingtip as described in claim 3, characterized in that, The flexible polymer material is at least one of TPU, TPC, TPA, TPE, or silicone.

5. The flexible wingtip as described in claim 4, characterized in that, The shell and the hollow structure are made of the same flexible polymer material or different flexible polymer materials.

6. The flexible wingtip as described in claim 5, characterized in that, The hollow structure is less flexible than the shell.

7. The flexible wingtip as described in claim 4, characterized in that, The hollow structure includes mounting holes that extend along the length of the flexible wingtip, and the cross-section of the mounting holes is circular and / or rectangular.

8. The flexible wingtip as described in claim 5, characterized in that, The length of the mounting hole is less than 1 / 2 of the length of the flexible wingtip.

9. The flexible wingtip as described in claim 6, characterized in that, The mounting holes are set close to the shell of the flexible wingtip.

10. The flexible wingtip as described in any one of claims 1-9, characterized in that, The flexible wingtip is made using a 3D printing method.

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