A winglet and an aircraft wing

Abstract

The application relates to a wing tip winglet and an airplane wing, which comprises a transition section, one end of the transition section being assembled on the end face of a wing tip of the airplane wing, the end face of the wing tip of the airplane wing extending to form the transition section, a first arc-shaped section with a partial elliptical shape, one end of the first arc-shaped section being arranged on the other end face of the transition section and being tangent to the transition section, a second arc-shaped section with a partial elliptical shape, one end of the second arc-shaped section being assembled on the other end of the first arc-shaped section, and the wing tip of the airplane wing, the transition section, the first arc-shaped section and the second arc-shaped section forming a curved surface with continuous curvature. In the design, the design parameters of the wing tip winglet are mainly the angle deflection difference value between the first ellipse and the second ellipse and the length of the major axis a, compared with the existing curved wing tip winglet, the design process is simplified, the curvature change of the guide line on the wing tip winglet is more continuous, and the lift-drag ratio of the whole wing is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wing tip winglet, in particular to a wing tip winglet and an airplane wing. BACKGROUND

[0002] The first wing tip winglet is a wing tip device in the form of an end plate simply installed at the wing tip. Since the drag reduction effect is not ideal, it is rarely used in practical applications. Later, the integrated wing tip winglet and shark fin wing tip winglet were gradually developed.

[0003] The design of the wing tip winglet is restricted by many factors, and the determination of the wing tip winglet parameters is one of them, mainly including the wing span (i.e. height) of the winglet, the aspect ratio, the installation angle, the twist angle, the dihedral angle, the root tip ratio, the forward sweep angle of the leading edge, and the backward sweep angle of the trailing edge. The influence of these parameters on the wing drag coefficient is different in degree. According to the research of relevant reference materials, it is found that the wing span, the inclined angle and the load are important factors affecting the induced drag. The wing tip winglet design is mainly used to reduce the induced drag of the airplane.

[0004] The guide line on the traditional wing tip winglet is a straight line, and a curve is used between the winglet and the wing. Although this design can block the flow of the lower surface of the wing to the upper surface and weaken the strength of the wing tip vortex, the lift-drag ratio of the wing tip is still not significant. Meanwhile, there are also wing tip winglets with curved guide lines. The parameters involved in the curved guide line are more, the radius is fixed, the curvature is not continuous, and the design process is complex. SUMMARY

[0005] The present application provides a wing tip winglet and an airplane wing, which can solve the problems of more design parameters, fixed radius, non-continuous curvature and complex design process in designing the curved guide line on the wing tip winglet.

[0006] The technical scheme of the present application is as follows: a wing tip winglet, comprising:

[0007] a transition section, one end of the transition section is assembled on one end surface of a wing tip of a wing, and the one end surface of the transition section and the one end surface of the wing tip of the wing are in shape conformity with each other;

[0008] a first arc-shaped section with a partial elliptical shape, one end of the first arc-shaped section is connected with the other end surface of the transition section, the one end surface of the first arc-shaped section is in shape conformity with the other end surface of the transition section, the first arc-shaped section is defined as a first ellipse, the major axis a of the first ellipse is perpendicular to the quarter chord line c of the wing tip of the wing, and the shape curve of the first arc-shaped section satisfies the formula: Wherein, x1, y1 represent the coordinate values of any point on the first ellipse on the x-axis and y-axis of the local coordinate system respectively, a1 is the long semi-axis length of the first ellipse, and b1 is the short semi-axis length of the first ellipse.

[0009] The second arc-shaped section has a partial elliptical shape, is connected with the other end of the first arc-shaped section, and the wing tip, the transition section, the first arc-shaped section and the second arc-shaped section form a curved surface with continuous curvature, the ellipse where the second arc-shaped section is located is defined as a second ellipse, the second ellipse has the same shape as the first ellipse, the center of the second ellipse is located on the long axis of the first ellipse, the second ellipse is tangent to the first ellipse, and the tangent point is located at the connection between the second arc-shaped section and the first arc-shaped section, and the shape curve of the second arc-shaped section satisfies the formula: Wherein, x2, y2 represent the coordinate values of any point on the second ellipse on the x-axis and y-axis of the local coordinate system respectively, a2 is the long semi-axis length of the second ellipse, and b2 is the short semi-axis length of the second ellipse.

[0010] By adopting the above scheme, the first arc-shaped section with a partial elliptical shape is set to be connected to the end face of the wing tip through the transition section. In the design, since the first arc-shaped section is tangent to the transition section and the long semi-axis is perpendicular to the quarter chord line of the wing tip, the position angle of the first ellipse can be determined according to the shape of the wing tip, and the position and deflection angle of the first arc-shaped section can be determined. At the same time, when designing the second arc-shaped section, only the second ellipse with the same shape as the first ellipse needs to be deflected in angle, and the center thereof needs to be moved along the long axis until it is tangent to the first ellipse. At this time, the tangent point position extends along the side away from the transition section, and the extended arc-shaped section is the second arc-shaped section. The design parameters of the wing tip winglet mainly include the angle deflection difference between the first ellipse and the second ellipse and the long semi-axis a length. Compared with the existing curved wing tip winglet, the design process is simplified, the deflection line curvature on the wing tip winglet changes more continuously, and the lift-drag ratio of the entire wing is improved.

[0011] In one embodiment of the present application, the included angle between the long axis of the first ellipse and the long axis of the second ellipse is defined as an inclination angle α, and the inclination angle α satisfies: 45°≤α≤65°.

[0012] The technical scheme has the advantages that, since the long semi-axis a of the first ellipse is always perpendicular to the quarter chord line c of the wing tip, the oblique included angle of the first ellipse can be improved according to the shape of different wing tips, the oblique included angle of the first arc segment is quickly determined, and then, by adjusting the oblique included angle alpha, that is, the difference between the first arc segment and the second arc segment, the oblique included angle of the second arc segment can also be quickly determined according to different types of wing tips, so that the two form a curvature-continuous curved surface, the determination convenience of the second arc segment is improved, and the relative oblique degree of the first arc segment and the second arc segment is adjusted by limiting the oblique included angle range, so that the curvature change of the whole wing tip winglet is more smooth.

[0013] In one of the embodiments of the present application, the short semi-axes b of the first ellipse and the second ellipse are both 1 / 10 of the wing half-span length.

[0014] By adopting the above scheme, the short semi-axes b of the first ellipse and the second ellipse are limited, so they can be customized according to different types of wing half-span lengths, thus compared with the conventional winglet with a curved upper reverse guide line, one design parameter feature is reduced, and thus the design process is simplified.

[0015] In one of the embodiments of the present application, the two end faces of the transition segment intersect at an intersection line s, and the intersection line s is located on the leading edge or the trailing edge of the wing tip.

[0016] By adopting the above scheme, the device can design two transition segments with different placement angles according to the actual working condition requirements, so as to set the angle deflection direction of the wing tip winglet and the wing in the xoy plane, change the included angle of the wing tip winglet and the flow, reduce the wing tip vortex, and thus reduce the aerodynamic drag.

[0017] In one of the embodiments of the present application, the end faces of the two ends of the transition segment intersect with each other and form an installation angle beta, and the installation angle beta satisfies: 0°<beta≤3°.

[0018] By adopting the above scheme, the installation angle beta range of the transition segment is set, so as to set the angle deflection range of the wing tip winglet and the wing in the xoy plane, further optimize the wing tip angle, and thus reduce the aerodynamic drag.

[0019] In one of the embodiments of the present application, the wing tip torsion angle theta of the wing tip winglet satisfies: -3°≤theta≤3°.

[0020] In one of the embodiments of the present application, the quarter chord line position sweep angle gamma of the wing tip winglet satisfies: 39°≤gamma≤50°.

[0021] By adopting the above scheme, other parameters of the wing tip winglet are limited, so that the wing tip winglet can block the flow of the lower surface of the wing to the upper surface during the flight of the wing, weaken the strength of the wing tip vortex, and improve the lift-drag ratio of the wing.

[0022] In one embodiment of the present application, the transition section comprises:

[0023] The first fixed strip is fixedly assembled on the end face of the first arc-shaped section away from the second arc-shaped section;

[0024] The second fixed strip is fixedly assembled on the end face of the wing tip, and an elastic metal sheet is arranged at one end of the second fixed strip close to the first fixed strip, and the elastic metal sheet is connected and fixed with the first fixed strip;

[0025] The first fixed strip and the second fixed strip are provided with T-shaped sliding grooves on the side close to each other, T-shaped sliding blocks are arranged on both sides of the sliding block and can slide in the T-shaped sliding grooves, and the sliding block is provided with a clamping piece for fixing the sliding block.

[0026] By adopting the above scheme, the transition section is designed as a component that can adjust the opening angle, so that the installation angle β of the transition section can be adjusted according to the actual working condition requirement during use, thereby avoiding the trouble of manufacturing a transition section with a custom angle according to the working condition, and improving the use and design convenience of the device.

[0027] In one embodiment of the present application, the clamping piece comprises:

[0028] The clamping strip is arranged in the strip-shaped sliding groove on the sliding block;

[0029] The elastic piece is arranged in the strip-shaped sliding groove, and the elastic piece is connected and fixed with the clamping strip and the inner wall of the strip-shaped sliding groove, respectively, one side of the second fixed strip is provided with a tooth groove extending along the length direction of the second fixed strip, and one end of the clamping strip can extend into the tooth groove and be clamped with the tooth groove.

[0030] By adopting the above scheme, when the angle of the transition section is adjusted according to the actual working condition requirement, the elastic piece continuously generates a thrust on the clamping strip by using the elasticity of the elastic piece itself, so that one end of the clamping strip can be clamped with the tooth groove, thereby ensuring that the sliding block will not be misoperated after the first fixed strip and the second fixed strip are opened.

[0031] The present application also relates to an airplane wing, and the specific technical scheme is as follows: an airplane wing comprises a wing tip winglet.

[0032] In summary, the present application has at least one of the following beneficial technical effects:

[0033] 1. By setting two first ellipses and second ellipses of the same shape, by changing the included angle between the first ellipses and the second ellipses, so as to change the curvature of the two arc segments determined by the two ellipses, so that the arc surface radius changes continuously when the two arc segments are connected, the curvature of the upper reverse characteristic curve of the whole wing tip winglet is more continuous and smooth, and the air resistance is reduced.

[0034] 2. By setting two arc segments determined by two ellipses, and by using two ellipses which can be determined according to the type of the wing, by changing the skew angle between the two, the arc surface shape of the two arc segments is determined, and then the shape of the whole wing tip winglet can be determined. In this design scheme, the design parameters of the first arc segment and the second arc segment are determined according to the actual half span of the wing, so compared with the existing design scheme, one important design parameter is saved, thereby simplifying the design process.

[0035] 3. By setting a transition section, by setting the included angle range of the two end faces of the transition section, since the transition section is arranged on the end face of the wing, the orientation of the wing end face is changed, and then the angle between the wing tip winglet and the flow is changed, the wing tip vortex is reduced, and the aerodynamic drag of the wing tip winglet is reduced.

[0036] 4. By setting a first fixed strip, a second fixed strip and a sliding block, by setting the first fixed strip and the second fixed strip which can be opened and closed, the first fixed strip and the second fixed strip adjust the installation angle of the whole transition section by opening and closing, and then adjust the angle between the first arc segment and the second arc segment and the flow, so that the device can fine tune the installation angle of the wing tip winglet according to the actual working condition, avoiding the trouble of re-designing and manufacturing, and saving the economic cost. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a front view of a wing tip winglet first ellipse and a second ellipse provided in the first embodiment of the application;

[0038] Figure 2 is a front view of a wing tip winglet when the intersection line is located at the leading edge of the wing tip of the wing in the first embodiment of the application;

[0039] Figure 3 is a plan view of a wing tip winglet when the intersection line is located at the leading edge of the wing tip of the wing in the first embodiment of the application;

[0040] Figure 4 is a front view of a wing tip winglet when the intersection line is located at the trailing edge of the wing tip of the wing in the first embodiment of the application;

[0041] Figure 5is a plan view of a wing tip winglet according to the first embodiment of the present application when the intersection line is located at the trailing edge of the wing tip;

[0042] Figure 6 is a front view of a sweep angle of a wing tip winglet according to the first embodiment of the present application;

[0043] Figure 7 is a front view of a wing tip winglet according to the first embodiment of the present application with or without a twist angle;

[0044] Figure 8 is a front view of a first fixing strip and a second fixing strip of a wing tip winglet according to the second embodiment of the present application;

[0045] Figure 9 is a front view of a T-shaped sliding groove of a wing tip winglet according to the first embodiment of the present application;

[0046] Figure 10 is Figure 8 is an enlarged view of part A.

[0047] BRIEF DESCRIPTION OF DRAWINGS 1, transition section; 11, first fixing strip; 111, elastic metal sheet; 12, sliding block; 121, T-shaped sliding block; 122, engaging member; 1221, clamping strip; 1222, elastic member; 123, strip-shaped sliding groove; 13, second fixing strip; 131, T-shaped sliding groove; 2, first arc-shaped section; 21, first ellipse; 3, second arc-shaped section; 31, second ellipse; 4, wing tip. DETAILED DESCRIPTION

[0048] The following will be described in detail with reference to the accompanying drawings. Figures 1-10 A wing tip winglet and an airplane wing according to the present application will be described in detail.

[0049] Please refer to Figure 1 A wing tip winglet according to the embodiment of the present application is assembled on the end face of a wing tip 4, and comprises a transition section 1, a first arc-shaped section 2 and a second arc-shaped section 3. The transition section 1 is assembled on one end face of the wing tip 4. The shape of the one end face of the transition section 1 is consistent with that of the one end face of the wing tip 4. The first arc-shaped section 2 has a partial ellipse shape. The one end of the first arc-shaped section 2 is connected to the other end face of the transition section 1. The shape of the one end face of the first arc-shaped section 2 is consistent with that of the other end face of the transition section 1. The shape curve of the first arc-shaped section 2 satisfies the formula: wherein x1 and y1 represent the coordinate values of any point on the first ellipse 21 in the local coordinate system x-axis and y-axis respectively, a1 is the long semi-axis length of the first ellipse 21, and b1 is the short semi-axis length of the first ellipse 21.

[0050] The second arc-shaped section 3 has a partial elliptical shape, the other end of the first arc-shaped section 2 is connected with the second arc-shaped section 3, the wing tip 4, the transition section 1, the first arc-shaped section 2 and the second arc-shaped section 3 form a curved surface with continuous curvature, the ellipse where the second arc-shaped section 3 is located is defined as a second ellipse 31, the second ellipse 31 has the same shape as the first ellipse 21, the center of the second ellipse 31 is located on the major axis of the first ellipse 21, the second ellipse 31 is tangent to the first ellipse 21, and the tangent point is located at the connection between the second arc-shaped section 3 and the first arc-shaped section 2, and the shape curve of the second arc-shaped section 3 satisfies the formula: Wherein, x2 and y2 respectively represent the coordinate values of any point on the second ellipse 31 on the x-axis and y-axis of the local coordinate system, a2 is the length of the major semi-axis of the second ellipse 31, and b2 is the length of the minor semi-axis of the second ellipse 31. By using two first ellipses 21 and second ellipses 31 with the same shape, the arc surface shapes of the first arc-shaped section 2 and the second arc-shaped section 3 are determined, so that the device can change the curvature of the first arc-shaped section 2 and the second arc-shaped section 3 by changing the included angle between the two ellipses during design, which is more convenient during design, and the curvature change between the first arc-shaped section 2 and the second arc-shaped section 3 is more continuous, thereby reducing air resistance.

[0051] Please refer to Figure 1 , the included angle between the major axis of the first ellipse 21 and the major axis of the second ellipse 31 is defined as an inclined

[0052] Inclined angle a, the inclined angle a satisfies: 45°≤a≤65°, by adjusting the angle of the inclined angle a, the relative inclination of the first arc-shaped section 2 and the second arc-shaped section 3 is adjusted, by changing the inclined angle between the two ellipses, the relative inclination of the first arc-shaped section 2 and the second arc-shaped section 3 is changed, which is convenient for parameter design of the wing, and is also more convenient in the test link of controlling variables.

[0053] In this embodiment, by changing the value of the inclined angle a and using the fluid mechanics (CFD) simulation software star-ccm+, the resistance coefficient obtained by simulation is used to determine the design parameters when the total machine aerodynamic resistance of the wing is the smallest.

[0054] Please refer to Figure 1 , the length of the minor semi-axis b of the first ellipse 21 and the second ellipse 31 is 1 / 10 of the half-span length of the wing, by limiting the length of the whole winglet, the device can limit the length in the length direction according to different types of wings, thereby reducing the design of the winglet in parameters.

[0055] Please refer to Figures 2-4The end faces of the transition section 1 at the two ends cross each other and form an installation angle β, the installation angle β satisfies: 0°<β≤3°, the end faces of the transition section 1 at the two ends form an intersection line s at the intersection, the intersection line s is located on the leading edge or the trailing edge of the wing tip 4, by setting the transition section 1 capable of being at an angle and setting it at the end face of the wing tip 4, the included angle between the winglet and the airflow can be changed to a certain extent, and the air resistance of the winglet is optimized.

[0056] The end faces of the transition section 1 at the two ends cross each other and form an installation angle β, the installation angle β satisfies: 0°<β≤3°, the end faces of the transition section 1 at the two ends form an intersection line s at the intersection, the intersection line s is located on the leading edge or the trailing edge of the wing tip 4, by setting the transition section 1 capable of being at an angle and setting it at the end face of the wing tip 4, the included angle between the winglet and the airflow can be changed to a certain extent, and the air resistance of the winglet is optimized.

[0057] In the embodiment, please refer to Figure 2 and Figure 3 At this time, the installation angle of the transition section 1 can be set to be towards the leading edge of the wing tip 4, please refer to Figure 4 and Figure 5 At this time, the installation angle of the transition section 1 can be set to be towards the trailing edge of the wing tip 4, so that the winglet can be adjusted in two directions to adapt to different wings.

[0058] Please refer to Figure 7 , the winglet tip twist angle θ of the winglet satisfies: -3°≤θ≤3°, by limiting the winglet tip twist angle of the winglet, the aerodynamic layout of the winglet can be further optimized.

[0059] Please refer to Figure 6 , the quarter-chord line position sweepback angle γ of the winglet satisfies: 39°≤γ≤50°, by limiting the sweepback angle of the winglet, the air resistance between the winglet and the airflow can be further reduced.

[0060] Embodiment 2

[0061] Please refer to Figure 8 , Figure 9 and Figure 10, embodiment 2 and embodiment 1 are basically the same structure, the difference is that: the transition section 1 includes: the first fixed strip 11, the second fixed strip 13 and the sliding block 12, fixedly assembled on the end face of the first arc section 2 away from the second arc section 3, fixedly assembled on the end face of the wing tip 4, the second fixed strip 13 is provided with an elastic metal sheet 111 close to one end of the first fixed strip 11, the elastic metal sheet 111 is connected and fixed with the first fixed strip 11, the first fixed strip 11 and the second fixed strip 13 are provided with T-shaped sliding grooves 131 on the side close to each other, the sliding block 12 is provided with T-shaped sliding blocks 121 which can slide in the T-shaped sliding grooves 131, the sliding block 12 is provided with clamping pieces 122 which can fix the sliding block 12, by setting the first fixed strip 11 and the second fixed strip 13 which can open and close each other, and using the sliding block 12 to assemble between the first fixed strip 11 and the second fixed strip 13, so that the first fixed strip 11 and the second fixed strip 13 can be opened at a certain angle and kept stable, so that the setting range of the installation angle beta of the transition section can be quickly adjusted.

[0062] Wherein, the first fixed strip 11 and the second fixed strip 13 are wrapped with a skin, so that when the device needs to change the width of the transition section 1, only the skin needs to be disassembled and replaced, so that the installation angle beta between the winglet and the wing tip of the wing can be quickly adjusted, compared with the existing technology, the economic cost is lower.

[0063] Please refer to Figure 9 The clamping piece 122 includes: a clamping strip 1221 and an elastic piece 1222, the sliding block 12 is provided with a strip-shaped sliding groove 123 extending towards the second fixed strip 13, the clamping strip 1221 is slidingly assembled in the strip-shaped sliding groove 123, the elastic piece 1222 is arranged in the strip-shaped sliding groove 123, the elastic piece 1222 is connected and fixed with the clamping strip 1221 and the inner wall of the strip-shaped sliding groove 123 respectively, the second fixed strip 13 is provided with a gear slot 131 extending along the length direction of itself on one side, one end of the clamping strip 1221 can extend into the gear slot 131 and be clamped with the gear slot 131, by using the elastic piece and the clamping strip in the device, when the sliding block 12 moves to the specified position between the first fixed strip 11 and the second fixed strip 13, the one end of the clamping strip 1221 is deeply inserted into the gear slot 131 and clamped with the gear slot 131 by the force exerted by the elastic piece 1222 on the clamping strip 1221, so that the sliding block 12 can be stably fixed after moving to the specified position.

[0064] The application also relates to an airplane wing.

[0065] In summary, the wing tip winglet can adjust the angle between the wing tip winglet and the incoming airflow by first setting a transition section 1 at the end face of the wing tip 4, which is in shape with the wing tip winglet and extends out, so as to improve the wing tip winglet tip vortex and reduce the drag on the whole wing.

[0066] In the design, first, the first ellipse 21 is set according to the type shape of the wing, so that the major axis of the first ellipse 21 is always perpendicular to the quarter chord line of the wing, so that the inclination angle of the first ellipse 21 can be quickly and conveniently determined. At the same time, since the minor axis of the first ellipse 21 and the second ellipse 31 can also be determined according to the half span of the wing, therefore, when designing the first ellipse 21 and the second ellipse 31, only the length of the major axis a of the two needs to be designed, and the inclination angle between the first ellipse 21 and the second ellipse 31 is designed, so that the arc surface shape between the first arc section 2 and the second arc section 3 can be quickly determined. Compared with the existing wing tip winglet curve design scheme using multiple circular arcs, the design parameters are less, and the radius of the wing tip winglet changes unfixedly, the curvature of the first arc section 2 and the second arc section 3 changes more continuously, and the air resistance is reduced.

[0067] The above are preferred embodiments of the present application, not to limit the protection scope of the present application, therefore: all equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A winglet, characterized in that, include: Transition section (1), one end of which is fitted onto one end face of the wingtip (4), and the shape of one end face of the transition section (1) matches that of one end face of the wingtip (4); A first arc segment (2) with a partially elliptical shape, one end of the first arc segment (2) is connected to the other end face of the transition segment (1), the shape of the end face of the first arc segment (2) matches the shape of the other end face of the transition segment (1), the ellipse containing the first arc segment (2) is defined as the first ellipse (21), the semi-major axis a of the first ellipse (21) is perpendicular to the quarter chord c of the wingtip (4), and the shape curve of the first arc segment (2) satisfies the formula: Where x1 and y1 represent the coordinates of any point on the first ellipse (21) on the x-axis and y-axis of the local coordinate system, respectively, a1 is the length of the major semi-axis of the first ellipse (21), and b1 is the length of the minor semi-axis of the first ellipse (21). A second arc segment (3) with a partial elliptical shape is connected to the other end of the first arc segment (2). The wingtip (4), transition segment (1), first arc segment (2), and second arc segment (3) form a surface with continuous curvature. The ellipse containing the second arc segment (3) is defined as the second ellipse (31). The second ellipse (31) has the same shape as the first ellipse (21). The center of the second ellipse (31) is located on the major axis of the first ellipse (21). The second ellipse (31) is tangent to the first ellipse (21), and the point of tangency is located at the connection between the second arc segment (3) and the first arc segment (2). The shape curve of the second arc segment (3) satisfies the formula: Where x2 and y2 represent the coordinate values ​​of any point on the second ellipse (31) on the x-axis and y-axis of the local coordinate system, respectively, a2 is the length of the major semi-axis of the second ellipse (31), and b2 is the length of the minor semi-axis of the second ellipse (31). The angle between the major axis of the first ellipse (21) and the major axis of the second ellipse (31) is defined as the inclination angle α, which satisfies: 45°≤α≤65°.

2. The winglet according to claim 1, characterized in that: The length of the minor axis b of both the first ellipse (21) and the second ellipse (31) is 1 / 10 of the wing's half-span.

3. A winglet according to claim 1, characterized in that: The two end faces of the transition section (1) form an intersecting line s at the intersection, and the intersecting line s is located on the leading or trailing edge of the wingtip (4).

4. A winglet according to claim 1, characterized in that: The end faces at both ends of the transition section (1) intersect each other and form an installation angle β, which satisfies: 0° < β ≤ 3°.

5. A winglet according to claim 4, characterized in that: The wingtip twist angle θ of the winglet satisfies: -3°≤θ≤3°.

6. A winglet according to claim 4, characterized in that: The sweep angle γ at the quarter-chord position of the winglet satisfies: 39°≤γ≤50°.

7. A winglet according to claim 1, characterized in that: The transition section (1) includes: The first fixing strip (11) is fixedly assembled on the end face of the first arc segment (2) away from the second arc segment (3); The second fixing strip (13) is fixedly mounted on the end face of the wingtip (4). An elastic metal piece (111) is provided at one end of the second fixing strip (13) near the first fixing strip (11). The elastic metal piece (111) is connected and fixed to the first fixing strip (11). The sliding block (12) has a T-shaped groove (131) on one side of the first fixing bar (11) and the second fixing bar (13) that are close to each other. The sliding block (12) has T-shaped sliders (121) on both sides that can slide inside the T-shaped groove (131). The sliding block (12) has a locking member (122) that can fix the sliding block (12).

8. A winglet according to claim 7, characterized in that: The engaging component (122) includes: The locking strip (1221) has a strip-shaped groove (123) extending toward the second fixed strip (13) on the sliding block (12), and the locking strip (1221) is slidably fitted inside the strip-shaped groove (123); An elastic element (1222) is disposed inside the strip groove (123). The elastic element (1222) is connected and fixed to the inner wall of the locking strip (1221) and the strip groove (123) respectively. A toothed groove (131) extending along its own length direction is provided on one side of the second fixing strip (13). One end of the locking strip (1221) can extend into the toothed groove (131) and engage with the toothed groove (131).

9. An aircraft wing, characterized in that: Including the winglets as described in any one of claims 1-8.

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