Eddy current interference device and method for increasing aircraft lift during landing

Abstract

This invention provides an eddy current interference device for aircraft. The device may include: a sheet-like body comprising a fixed end and a connecting end. The fixed end is positioned behind the landing gear and fixed to its support structure as viewed along the aircraft's flight direction. The connecting end is positioned closer to the landing gear wheels than the fixed end. Multiple elongated elements are distributed along the width of the sheet-like body, with one end connected to the connecting end and the opposite end being a free end. These elongated elements are used to interfere with eddy currents generated at the landing gear during flight. By installing the aforementioned eddy current interference device at the landing gear, eddy currents can be interfered with at a very low cost and with reliable effects verified by wind tunnel testing, thereby increasing aircraft lift during landing and significantly improving landing safety. This invention also relates to a method for increasing aircraft lift during landing.

Description

Technical Field

[0001] This invention relates to the field of aircraft, and more specifically to a vortex interference device for increasing aircraft lift during landing and a method for increasing aircraft lift during landing. Background Technology

[0002] Typically, aircraft need to reduce speed during landing. This is because reducing the aircraft's kinetic energy during landing allows for better control of the landing attitude or avoids collisions with the runway or other obstacles. To reduce kinetic energy, engine throttle must be reduced during landing, decreasing engine power output and thus slowing the aircraft down. This reduced speed decreases the efficiency of lift generated by the aircraft's wings. However, slower speed also makes the aircraft more susceptible to stalling during landing, and controlling a stall requires maintaining sufficient lift to ensure stability.

[0003] An aircraft's approach speed is one of the indicators for evaluating its landing performance. If the approach speed is too high (>140kt), the aircraft is at risk of being downgraded. Therefore, during the aircraft design phase, all feasible measures are taken to reduce the aircraft's approach speed while ensuring safety.

[0004] Therefore, existing aircraft can increase lift by deploying flaps and slats under landing configuration conditions, aiming to gradually reduce speed for landing. It is known that during landing approach, the nose landing gear is deployed, and the detached vortices dragged by the landing gear wheels hit the leading edge at the wing root. This creates an upwash, causing flow separation downstream of the upper wing surface. This results in insufficient lift, forcing the aircraft to increase its landing approach speed.

[0005] In existing technologies, a common approach is to add serrated guide vanes to the tips of the inner slats to disrupt the detached vortex of the aircraft's nose landing gear, thereby improving lift under landing configuration conditions and reducing the aircraft's landing approach speed.

[0006] However, the aforementioned solutions primarily focus on wing modifications, i.e., implementing improvements downstream of the airflow. In particular, the relevant components are fixed, representing a passive control approach. For aircraft already in development, modifying the inner slat structure and installing new components would involve extensive changes to drawings and tooling, significantly increasing time and cycle costs. Furthermore, the sensitivity to differences in the redesigned inner slat flap shape and installation location necessitates wind tunnel testing for selection, leading to additional testing funding and a longer development cycle.

[0007] Therefore, in the field of aircraft, especially for increasing the lift of an aircraft during landing, there has always been a need to achieve this at a lower cost and with less modification to the existing structure. Summary of the Invention

[0008] This invention provides an eddy current interference device for an aircraft. The eddy current interference device may include: a sheet-like body, the sheet-like body including a fixed end and a connecting end, the fixed end being fixed to the support portion of the landing gear behind it when viewed along the flight direction of the aircraft, and the connecting end being closer to the landing gear wheel than the fixed end; and a plurality of elongated elements, which may be distributed along the width direction of the sheet-like body, one end of which is connected to the connecting end, and the opposite end of which may be a free end, the plurality of elongated elements being used to interfere with the eddies generated at the landing gear during flight.

[0009] By installing the aforementioned eddy current interference device at the landing gear, eddy currents, especially detached eddy currents, can be interfered with at a very low cost and with reliable effects verified by wind tunnel tests. This increases the aircraft's lift during landing and significantly improves landing safety. In particular, the eddy current interference device of this invention is an active control method that does not require fundamental structural modifications to existing aircraft. It can be easily integrated with the landing gear of various aircraft, making it highly flexible and adaptable.

[0010] Preferably, the eddy current interference device can be arranged along the width direction between each directional light of the landing gear, wherein the fixed end can be fixed to the crossbar between the directional lights.

[0011] This arrangement allows for easy installation of the eddy current jamming device in a fixed position on the landing gear and provides accommodation space when the eddy current jamming device is not in operation.

[0012] Advantageously, the free end of the elongated element can be located above the wheel, or the free end of the elongated element can be located above the central axis of the wheel.

[0013] By limiting the length of slender components and eddy current interference devices, it is possible to prevent undesirable entanglement of slender components into the landing gear wheels, as this reduces the interference effect of the eddy current interference devices on eddies (e.g., breaking up detached eddies).

[0014] In particular, the sheet-like body and elongated elements may include elastomeric materials; for example, the eddy current interference device may be made of rubber.

[0015] Elastomer materials facilitate the retention of eddy current jamming devices on the landing gear and provide reliable toughness to prevent problems such as breakage of the eddy current jamming devices during operation.

[0016] Advantageously, the elongated element can be integrated with the sheet-like body and can extend from the bottom of the sheet-like body. This structure facilitates the manufacture of the eddy current interference device and ensures a stable connection between the sheet-like body and the elongated element.

[0017] Preferably, the multiple elongated elements can be of the same size, wherein the width of each of the multiple elongated elements can be 1-3 cm, particularly 2 cm.

[0018] Slender elements of the same size are easier to manufacture, while thinner slender elements help to break up eddies, such as detached eddies generated at the landing gear wheels, into smaller, more localized eddies, significantly improving the eddy current interference effect.

[0019] In particular, the length of the sheet-like body can be approximately one-quarter to one-half the length of the elongated element, for example, one-third.

[0020] Making the length of the sheet-like main body smaller than that of the slender element allows the slender element to act more effectively on the disruptive eddies, especially breaking up disintegrating eddies. The length of the sheet-like main body should also not be too small, as this part is mainly used to hold the eddy current disruptor on the landing gear.

[0021] In particular, there can be more than ten slender elements distributed along the width direction.

[0022] By using a large number of slender elements, eddies, especially detached eddies, can be broken into more localized smaller eddies, thereby improving the interference effect and achieving a stable increase in lift.

[0023] Furthermore, the eddy current jamming device may also include a clamping element for pressing the sheet material between the support portion and the clamping element, thereby securing it to the support portion. The clamping element allows the eddy current jamming device, primarily sheet-like, to be reliably secured to the landing gear.

[0024] The present invention also provides a method for increasing the lift of an aircraft during landing, the method comprising: an installation step of installing the vortex interference device as described above on the landing gear of the aircraft, and an operation step of allowing the vortex interference device to move freely after the landing gear is lowered during landing, thereby interfering with the detached vortex generated at the landing gear.

[0025] By employing the eddy current interference device of the present invention, the lift of an aircraft during landing can be significantly improved with very low cost and highly reliable results, thereby enhancing the safety of aircraft landing. In particular, the method of the present invention does not require fundamental structural modifications to existing aircraft, making it highly adaptable.

[0026] Preferably, the method may further include separating a plurality of elongated elements from a piece of material, starting from a predetermined position along the length of the material.

[0027] Eddy current interference devices can be easily manufactured from monolithic materials, especially by separating slender elements from monolithic materials. This method is low-cost and offers better structural stability.

[0028] Advantageously, the installation steps may include rolling up the eddy current jamming device onto a crossbar between the heading lights and locking it with a locking element; the action steps may include releasing the lock and deploying the eddy current jamming device after the landing gear is lowered.

[0029] Locking the eddy current jamming device in place using locking elements prevents accidental detachment or interference with the landing gear itself when it is not needed (e.g., preventing it from getting caught in the wheels). Retraction and extension allow for free (e.g., depending on the current flight state of the aircraft) control of eddies, such as detached eddies. Attached Figure Description

[0030] Figure 1 A side view of an eddy current jamming device according to an embodiment of the present invention is schematically shown, wherein the eddy current jamming device has been mounted on an aircraft landing gear;

[0031] Figure 2 A schematic front view of an eddy current jamming device according to an embodiment of the present invention is shown, wherein the eddy current jamming device is mounted on a crossbar between two landing gear yaw lights;

[0032] Figure 3 A schematic top view of an eddy current interference device according to an embodiment of the present invention is shown, wherein the eddy current interference device is disposed between the landing gear support portion and the clamping element.

[0033] Figure 4A and 4B The diagrams schematically show a comparison of eddy current conditions before and after the application of an eddy current interference device according to an embodiment of the present invention on an aircraft landing gear.

[0034] List of reference numerals in the attached diagram:

[0035] 100 landing gear;

[0036] 110 Navigation Light;

[0037] 120 Main support section;

[0038] 130 wheels

[0039] 132 (the wheel's) central axis;

[0040] 140 crossbar;

[0041] 150 clamping element;

[0042] 160 rivets;

[0043] 200 Eddy Current Interference Device

[0044] 210 Flake body;

[0045] 212 Fixed end;

[0046] 214 Connection terminal;

[0047] 220 Slender components;

[0048] 222 Free end;

[0049] 300a (unbroken) detached vortex;

[0050] 300b: The shattered detached vortex;

[0051] 400 in the width direction;

[0052] 500 ahead. Detailed Implementation

[0053] The present invention will be further described below with reference to specific embodiments and accompanying drawings, but this should not be construed as limiting the scope of protection of the present invention.

[0054] First, this invention primarily relates to the field of aircraft, and more particularly to measures for increasing aircraft lift during landing. Although this invention mainly concerns increasing aircraft lift during landing by interfering with eddies generated at the landing gear, those skilled in the art will understand that the eddy current interference device of this invention can also be applied to specific locations on an aircraft other than the landing gear, as long as a target for interfering with eddies exists at that specific location.

[0055] Secondly, descriptions involving direction, such as "forward," "rear," "below," and "lateral," are all based on the aircraft's orientation during normal flight. For example, "forward" is closer to the nose of the aircraft, while "rear" is closer to the tail, and "lateral" is the direction perpendicular to the aircraft's flight direction or the width of the aircraft.

[0056] Finally, it is worth noting that the numerical values ​​given in the various embodiments are merely examples and are not intended to limit the scope of the invention.

[0057] This invention provides an eddy current interference device 200. Here, the term "eddy current" refers to an eddy current that needs to be interfered with during flight, including but not limited to various detached eddies. The eddy current interference device 200 of this invention is not limited to interfering with eddies at the (front) landing gear 100 of an aircraft. Furthermore, the term "interference" refers to any means of reducing or eliminating the effect or influence of eddies in various ways, including but not limited to blocking, flow obstruction, breaking, shattering, and destruction.

[0058] The eddy current interference device 200 includes a sheet-like body 210 and a plurality of elongated elements 220. Here, the term "sheet-like" means that the thickness of the body is significantly smaller than its other dimensions (length, width), for example, they are not on the same order of magnitude. The term "elongated" means that the width of the element is significantly smaller than its length, for example, they are not on the same order of magnitude.

[0059] The sheet-like body 210 includes a fixed end 212 and a connecting end 214. Here, the term "end" refers to a portion, and not necessarily the very end of the sheet-like body 210, although an end or end portion is preferred. The fixed end 212 and the connecting end 214 are two different ends (parts) of the sheet-like body 210 and are therefore spaced apart from each other. The fixed end 212 is used to secure the landing gear 100 to its support portion behind it, viewed along the aircraft's flight direction, while the connecting end 214 is closer to the wheels 130 of the landing gear 100 than the fixed end 212. Figure 2 It can be seen that the connecting end 214 is located below the fixed end 212 (that is, closer to the plurality of elongated elements 220 than the fixed end 212).

[0060] Here, the support portion of the landing gear 100 can refer to the fixed portion of the landing gear 100 other than the rolling wheels 130. In some embodiments, the fixed end 212 can be fixed to the crossbar 140 between the yaw lights 110 of the landing gear 100, so that the eddy current interference device 200 is arranged between the yaw lights 110 of the landing gear 100 when viewed in the width direction 400. However, this is not limiting; for example, it can also be fixed to other fixed portions of the landing gear 100, such as the main support portion 120 of the landing gear 100. In this invention, it is not excluded that the eddy current interference device 200 is fixed by means of portions other than the fixed end 212; the fixed end 212 is merely one of the main fixed portions.

[0061] Multiple elongated elements 220 are distributed along the width direction of the sheet-like body 210, with one end connected to a connecting end 214 along their length, and the other opposite end being a free end 222. Here, the term "connected" can include being connected in various known ways or because they are integral. "Distributed along the width direction" means that the multiple elongated elements 220 are adjacent to each other along the width direction, and the width direction of each elongated element 220 is the same as or substantially the same as the width direction of the sheet-like body 210. In some embodiments, at least some of the multiple elongated elements 220 are spaced apart from each other along the width direction. In other embodiments, at least some of the multiple elongated elements 220 are abutting each other along the width direction (i.e., not spaced apart). Furthermore, the term "free end 222" means that its movement is not restricted by other components, for example, it can float in flight.

[0062] The eddy current interference device 200 of the present invention is used to interfere with eddies, such as detached eddies, generated at the (front) landing gear 100 during (landing) flight. In operation, the eddy current interference device 200, particularly its multiple elongated elements 220, oscillates with the wind. Each elongated element 220 (e.g., in the form of a strip) oscillates at a different frequency. These elongated elements 220 disrupt the detached eddies (which have a fixed frequency and period) generated at the wheels 130 of the (front) landing gear 100, breaking them down into different, smaller eddies whose energy dissipates rapidly in the flow.

[0063] As by Figures 4A-4B As most clearly shown, without the use of the eddy current interference device 200 of the present invention, a detached vortex is formed behind the wheel 130 of the landing gear 100 (viewed along the flight direction). However, when the eddy current interference device 200 of the present invention is used, the plurality of elongated elements 220 of the eddy current interference device 200 can "break up" at least part of the detached vortex in the eddy current field, making it smaller and more localized. Figure 4B The image shows the broken-off vortex 300b, which reduces the impact of the vortex on the aircraft's lift during landing, thus increasing the aircraft's landing lift.

[0064] exist Figure 2 In the illustrated embodiment, the nose landing gear 100 includes two yaw lights 110 spaced apart from each other along the width direction 400 of the aircraft. A crossbar 140, or beam, is disposed between the yaw lights 110. As previously mentioned, the eddy current interference device 200 is preferably fixed to this crossbar 140. Figure 3 As shown, the eddy current jamming device 200, mainly a sheet material, can be pressed between the support portion and the clamping element 150 using the clamping element 150, thereby fixing the eddy current jamming device 200 to the support portion, for example, the crossbar 140 between the landing gear 100 and the landing gear 110. In other words, the landing gear 100's landing gear 110 and its crossbar 140 are located 500 meters in front of the eddy current jamming device 200, while the eddy current jamming device 200 is located 500 meters in front of the clamping element 150.

[0065] As previously described, the elongated elements 220 can be integral with the sheet-like body 210, wherein each elongated element 220 extends from the base of the sheet-like body 210. In some embodiments, the sheet-like body 210 and the plurality of elongated elements 220 can be formed from a single piece of material, wherein the plurality of elongated elements 220 can be separated from the sheet material at a predetermined position along its length. The predetermined position may be, for example, one-quarter to one-half, particularly one-third, of the length of the sheet material from top to bottom. Separation can be achieved, for example, by cutting, trimming, or various cold and hot processing. After the plurality of elongated elements 220 are separated, the sheet material can be further processed, such as by further trimming to the appropriate width and / or length of the elongated elements 220, without being limited to the dimensions of the sheet material itself, which will not be elaborated here.

[0066] In this invention, the length of the sheet-like body 210 can be approximately one-quarter to one-half the length of the elongated elements 220. Essentially, the length of the sheet-like body 210 is always less than the length of the multiple elongated elements 220. This is partly because it allows the multiple elongated elements 220 with free ends 222 to more effectively disrupt eddy currents behind the wheel 130, and partly because the length of the sheet-like body 210 is designed to ensure a secure connection with the landing gear 100 and to reduce the impact on the function of the eddy current interference device 200 caused by entanglement between the multiple elongated elements 220.

[0067] The dimensions (width, length, etc.) of the multiple elongated elements 220 can be the same or different. Identical elongated elements 220 are convenient to manufacture (e.g., cut from a single piece of material), while different elongated elements 220 can satisfy different local eddy current interference effects along the width direction. For example, the elongated elements 220 located on both sides are shorter to prevent them from getting tangled in the wheels 130 of the landing gear 100. In some embodiments, the width of each of the multiple elongated elements 220 is 1-3 cm, preferably 2 cm.

[0068] It is understood that, in this invention, the number of “multiple” elongated elements 220 should be sufficient to ensure at least partial interference with the eddy currents behind the landing gear 100. In a preferred embodiment, more than ten, for example fifteen or twenty, elongated elements 220 may be distributed along the width direction of the eddy current interference device 200.

[0069] Preferably, the eddy current interference device 200 of the present invention comprises an elastomeric material. For example, the eddy current interference device 200 may be constructed from rubber strips. Preferably, the sheet-like body 210 and the plurality of elongated elements 220 may be made from the same rubber sheet, wherein the plurality of elongated elements 220 can be regarded as multiple rubber strips or strip-shaped belts. The elasticity or hardness of the material of the eddy current interference device 200 can be determined based on flight tests to ensure optimal eddy current interference effect. Preferably, the elastomeric material is generally lightweight and soft in texture.

[0070] According to the present invention, the free ends 222 of the eddy current interference device 200, i.e., the free ends 222 of the plurality of elongated elements 220, when the eddy current interference device 200 is fully relaxed and deployed (naturally hanging) in non-flight conditions, can be located above the wheels 130 of the landing gear 100, or above the central axis 132 of the wheels 130 of the landing gear 100, or at the central axis 132 (the center of the wheel 130) (see...). Figure 1 This is to prevent it from being caught in the wheel 130. It can be understood that during flight, the free ends 222 of the multiple elongated elements 220 can be located at different heights, which is a relatively random process (although it can also be controlled to some extent by designing the dimensions of the individual elongated elements 220, such as their length), mainly depending on the flow conditions of the multiple elongated elements 220 in the vortex, which tends to make the broken vortices different from each other.

[0071] In one example, the upper end of the eddy current jamming device 200 is fixed to the crossbeam of the yaw light 110 of the nose landing gear 100, and the lower end is cut into multiple slender elements 220 (multiple strips of ribbon) evenly and at equal intervals, with the ends of the lower end roughly flush with the center of the wheel 130 of the landing gear 100. The clamping element 150 can be directly fixed to the bracket portion, such as the crossbeam 140 of the yaw light 110, using fasteners such as rivets 160. Figure 3 As shown in the image.

[0072] The method for increasing aircraft lift during landing according to the present invention may include an installation step before flight and an action step during actual flight, i.e., during landing. Furthermore, the method may also include a production step or forming step prior to the installation step (e.g., separating, for example, cutting out, a plurality of elongated elements 220 from a sheet of material, starting from a predetermined position along its length, as previously described).

[0073] The installation steps include mounting the eddy current jamming device 200 onto the aircraft landing gear 100, primarily onto the support structure, such as the crossbar 140 between the wayfinding lights 110. Preferably, for ease of installation, the eddy current jamming device 200 can be rolled up onto the support structure, such as the crossbar 140, during installation to reduce unnecessary contact, interference, or even entanglement between the eddy current jamming device 200, particularly the multiple elongated elements 220, and the wheels 130 or other parts of the landing gear 100. After the eddy current jamming device 200 is rolled up, it can be locked by a locking element (e.g., an electronic lock) to prevent accidental unfolding or detachment, thereby improving safety.

[0074] The action steps include, after the landing gear 100 is lowered upon landing, allowing the eddy current jamming device 200 to move freely, thereby jamming (e.g., breaking up) the detached vortices generated at the landing gear 100. The timing of the specific action steps can be selected by the pilot or pre-programmed for automatic execution in the control program. For example, the action steps may include lowering and deploying the eddy current jamming device 200 by releasing the locking element after the landing gear 100 is lowered. Here, "lowering" and "deploying" refer to actions that prevent the eddy current jamming device 200 from being coiled around a support portion, such as the crossbar 140 of the heading light 110. The term "free movement" here means that the free end 222 of the eddy current jamming device 200 can sway with the wind, rather than that the eddy current jamming device 200 moves completely unrestrained (due to its fixed mounting to the support portion of the landing gear 100, such as the crossbar 140 of the heading light 110).

[0075] In this invention, to improve aircraft lift during landing and thus enhance landing safety, the primary approach focuses on disrupting the eddies, mainly detached eddies, formed at the landing gear 100 during landing. Compared to existing methods for improving aircraft lift during landing, this method is an active control approach and has been verified through wind tunnel testing, achieving satisfactory eddy current disruption at a very low cost. In particular, the method and apparatus of this invention do not require redesigning or altering any structure of existing aircraft, making them applicable to any current aircraft model. They are flexible and convenient to deploy and have excellent adaptability, significantly reducing costs and minimizing the manpower and resources required to improve aircraft lift during landing.

[0076] Although various embodiments of the invention have been described in the accompanying drawings with reference to eddy current interference devices installed at the aircraft landing gear and methods for improving lift during aircraft landing by installing eddy current interference devices, it should be understood that embodiments within the scope of the invention can be applied to other applications on aircraft with similar structures and / or functions that require eddy current interference.

[0077] The foregoing description has already given many features and advantages, including various alternative implementations, as well as details of the structure and function of the apparatus and methods. This document is intended to be exemplary and is not exhaustive or limiting.

[0078] It will be apparent to those skilled in the art that various modifications can be made within the full scope indicated by the broad superordinate meaning of the terms expressed in the appended claims, particularly in terms of structure, materials, elements, components, shapes, dimensions, and arrangements of components, including combinations of these aspects within the scope of the principles described herein. Such various modifications are intended to be included herein, provided they do not depart from the spirit and scope of the appended claims.

Claims

1. An eddy current interference device for aircraft, characterized in that, The eddy current interference device includes: A sheet-like body, the sheet-like body including a fixed end and a connecting end, the fixed end being used to fix to the support portion of the nose landing gear behind it when viewed along the flight direction of the aircraft, and the connecting end being closer to the wheel of the nose landing gear than the fixed end. Multiple elongated elements, comprising an elastomeric material, are distributed along the width of the sheet-like body, with one end connected to the connecting end and the opposite end being a free end. The free end extends in the height direction to the wheel of the nose landing gear. The multiple elongated elements are used to break up detached vortices generated behind the nose landing gear into smaller, more localized vortices during flight, thereby reducing the adverse effects of vortices on the aircraft's landing lift.

2. The eddy current interference device as described in claim 1, characterized in that, The eddy current interference device is arranged along the width direction between each directional light of the nose landing gear, wherein the fixed end is fixed to the crossbar between the directional lights.

3. The eddy current interference device as described in claim 1, characterized in that, The free end of the elongated element is located above the wheel of the front landing gear, or the free end of the elongated element is located above the central axis of the wheel.

4. The eddy current interference device as described in claim 1, characterized in that, The sheet-like body comprises an elastomeric material.

5. The eddy current interference device as described in claim 1, characterized in that, The elongated element is integral with the sheet-like body and extends from the bottom of the sheet-like body.

6. The eddy current interference device as described in claim 1, characterized in that, The plurality of elongated elements are of the same size, wherein the width of each of the plurality of elongated elements is 1-3 cm.

7. The eddy current interference device as described in claim 1, characterized in that, The length of the sheet-like body is one-quarter to one-half the length of the elongated element.

8. The eddy current interference device as described in claim 1, characterized in that, More than ten slender elements are distributed along the width direction.

9. The eddy current interference device as described in claim 1, characterized in that, It also includes a clamping element for pressing the sheet-like body between the support portion and the clamping element, thereby fixing it to the support portion.

10. A method for increasing aircraft lift during landing, characterized in that, The method includes: Installation steps: Install the eddy current jamming device as described in any one of claims 1-9 onto the nose landing gear of the aircraft. Operation steps: After the nose landing gear is lowered during landing, the eddy current interference device is allowed to move freely, thereby interfering with the detached eddy current generated at the nose landing gear.

11. The method as described in claim 10, characterized in that, It also includes separating the plurality of elongated elements from a piece of material, starting from a predetermined position along the length of the piece of material.

12. The method as described in claim 10, characterized in that, The installation steps include rolling the eddy current jamming device onto a crossbar between the yaw lights of the nose landing gear and locking it with a locking element; the operation steps include releasing the lock to lower and deploy the eddy current jamming device after lowering the nose landing gear.

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