A gust load mitigation device based on micro-aircraft and micro-aircraft

Abstract

The embodiment of the present application provides a gust load mitigation device based on a micro-aircraft and a micro-aircraft, which belongs to the field of gust mitigation technology. The gust load mitigation device based on a micro-aircraft includes a wing. Among them, the wing includes: a rigid frame and a flexible wing surface; the flexible wing surface is located on at least one side of the rigid frame; a preload adjustment mechanism, the preload adjustment mechanism is used to adjust the preload of the flexible wing surface, and the flexible wing surface is connected to the rigid frame when adjusted to a preset preload. The micro-aircraft includes a main body and the above-mentioned gust load mitigation device based on a micro-aircraft. In this way, by setting up a gust load mitigation device based on a micro-aircraft and utilizing the unique advantages of the adaptive deformation of the flexible wing surface, the wing surface flow separation can be effectively suppressed, and while the time-averaged lift coefficient is increased, the lift coefficient pulsation can be reduced to achieve gust load mitigation.

Description

Technical Field

[0001] The present application relates to the technical field of gust mitigation, and in particular to a gust load mitigation device based on a micro air vehicle and a micro air vehicle. Background Art

[0002] Micro air vehicles are a type of small, lightweight unmanned aerial vehicles that are compact, flexible, and low-cost. They can be used in a variety of scenarios such as military reconnaissance, environmental monitoring, and emergency rescue, and have important application prospects in the future aviation field. However, due to the low flight speed and altitude of micro air vehicles, they are susceptible to gusts in the atmospheric boundary layer, which can cause flow separation and drastic changes in wing loads, ultimately leading to deterioration of aerodynamic performance and endangering flight stability, controllability, and safety. Therefore, gust mitigation of micro air vehicles has attracted widespread attention in the aviation field.

[0003] Among them, in traditional aircraft design, the design of rigid wings is based on the main flight conditions such as cruising, while taking into account the compromise optimization achieved by important flight processes such as take-off and landing. It can only achieve the optimal aerodynamic performance at limited design points and is difficult to adapt to complex and changeable gust environments. Traditional gust mitigation methods generally require precise coordination of hardware such as sensors and rigid control surfaces with control algorithms to maintain flight stability.

[0004] However, the traditional gust mitigation control system includes sensors, control algorithms, control surfaces, etc., and the system structure is complex. In addition, it is necessary to design special mitigation control algorithms for different flight environments and work tasks, which is costly. Since the control system requires the installation of multiple sets of active control mechanisms, the additional weight is large, and it is often suitable for large aircraft and difficult to apply to micro-aircraft. The rigid trailing edge has structural gaps and sudden changes in curvature, which makes it difficult to ensure the smooth change of aerodynamic force. Summary of the invention

[0005] The embodiment of the present application provides a gust load mitigation device based on a micro-aircraft and a micro-aircraft. By setting up a gust load mitigation device based on a micro-aircraft and utilizing the unique advantages of the adaptive deformation of the flexible wing surface, the flow separation on the wing surface can be effectively suppressed. While improving the time-averaged lift coefficient, the pulsation of the lift coefficient can be reduced, thereby achieving gust load mitigation.

[0006] In order to achieve the above objectives, the embodiments of the present application provide the following technical solutions:

[0007] A first aspect of an embodiment of the present application provides a gust load mitigation device based on a micro air vehicle, comprising:

[0008] The wing comprises: a rigid frame and a flexible wing surface, wherein the flexible wing surface is located on at least one side of the rigid frame;

[0009] The preload adjusting mechanism is used to adjust the preload of the flexible wing surface. When the flexible wing surface is adjusted to a preset preload, it is connected to the rigid frame.

[0010] Based on the above technical solution, the present application can also be improved as follows.

[0011] In one possible implementation, the wing has a windward surface and a leeward surface;

[0012] The flexible wing surface is elastic and can produce elastic deformation. Under the action of aerodynamic load, there is a pressure difference between the windward side and the leeward side of the wing, causing the flexible wing surface to deflect and deform toward the leeward side of the wing through elastic deformation, resulting in an increase in the camber, so that the time-averaged lift of the wing increases;

[0013] When the wing encounters vertical gusts, the flexible wing surface produces adaptive deformation according to the strength of the gust, and balances the additional load brought by the gust by changing the tension inside the flexible wing surface; when the gust strengthens, the curvature of the wing with the flexible wing surface increases, the ability to resist the flow separation caused by the gust is enhanced, the pulsation of the lift coefficient is reduced, and the gust load is reduced.

[0014] In one possible implementation, the flexible airfoil coincides with the rigid frame on one side of the rigid frame;

[0015] Or the flexible airfoil covers part of the rigid frame on one side of the rigid frame;

[0016] Alternatively, the flexible wing surfaces are located on both sides of the rigid frame.

[0017] In a possible implementation, the thickness of the flexible airfoil ranges from 0.2 mm to 2 mm.

[0018] In a possible implementation, the elastic modulus of the material of the flexible wing surface is in the range of 1 MPa to 50 MPa.

[0019] In a possible implementation, the material of the flexible wing surface is made of a high molecular polymer film;

[0020] The high molecular polymer film is a thermoplastic polyurethane elastomer film or a polyvinyl chloride film.

[0021] In a possible implementation, the flexible wing surface and the rigid frame are connected by adhesive, riveting or heat shrink fastening.

[0022] In a possible implementation, the rigid skeleton is in a rectangular, elliptical, trapezoidal or triangular shape.

[0023] In a possible implementation, the preload force adjustment mechanism includes: a first clamp, a second clamp, a base, and a displacement platform;

[0024] The first fixture is located on the base, and the second fixture is located on the translation stage;

[0025] The first clamp is used to clamp one end of the flexible wing surface, and the second clamp is used to clamp the other end of the flexible wing surface;

[0026] The flexible wing surface is stretched by adjusting the translation stage so that the flexible wing surface reaches a preset preload.

[0027] A second aspect of an embodiment of the present application provides a micro air vehicle, comprising a main body and the above-mentioned gust load mitigation device based on the micro air vehicle.

[0028] The embodiment of the present application provides a gust load mitigation device based on a micro-aircraft and a micro-aircraft, wherein the gust load mitigation device based on a micro-aircraft includes a wing. The wing includes: a rigid frame and a flexible wing surface; the flexible wing surface is located on at least one side of the rigid frame; a preload adjustment mechanism, the preload adjustment mechanism is used to adjust the preload of the flexible wing surface, and the flexible wing surface is connected to the rigid frame when adjusted to a preset preload. The micro-aircraft includes a main body and the above-mentioned gust load mitigation device based on a micro-aircraft. In this way, by setting up a gust load mitigation device based on a micro-aircraft and utilizing the unique advantages of the adaptive deformation of the flexible wing surface, the wing surface flow separation can be effectively suppressed, and while the time-averaged lift coefficient is increased, the lift coefficient pulsation can be reduced to achieve gust load mitigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A top view of a gust load mitigation device based on a micro air vehicle provided in one embodiment of the present application;

[0031] Figure 2 A schematic structural diagram of a preload adjustment mechanism of a gust load mitigation device based on a micro air vehicle provided in one embodiment of the present application;

[0032] Figure 3 A cross-sectional schematic diagram of a gust load mitigation device based on a micro air vehicle provided in one embodiment of the present application;

[0033] Figure 4 A schematic diagram of a single-layer structure, a double-layer structure, and a partial structure of a gust load mitigation device based on a micro air vehicle provided in one embodiment of the present application;

[0034] Figure 5 A schematic diagram of the structure of a micro air vehicle with different wing shapes provided in one embodiment of the present application;

[0035] Figure 6 A lift coefficient curve obtained from a wind tunnel force measurement test of a gust load mitigation device based on a micro air vehicle provided in one embodiment of the present application;

[0036] Figure 7 A lift coefficient pulsation curve obtained from a wind tunnel force measurement test of a gust load mitigation device for a micro air vehicle provided in one embodiment of the present application;

[0037] Figure 8 A time-averaged streamline diagram obtained from a wind tunnel force measurement test of a gust load mitigation device based on a micro air vehicle provided in one embodiment of the present application.

[0038] Description of reference numerals:

[0039] 100-Gust load mitigation device based on micro air vehicle;

[0040] 200 - Wing;

[0041] 210-rigid frame; 220-flexible wing surface; 230-windward surface; 240-leeward surface;

[0042] 300-Preload adjustment mechanism;

[0043] 310 - first fixture; 320 - second fixture; 330 - base; 340 - translation stage; 341 - knob;

[0044] 400-MAV;

[0045] 410-Main body. DETAILED DESCRIPTION

[0046] As described in the background technology, the current gust mitigation control system includes sensors, control algorithms, control surfaces, etc., and the system structure is complex. In addition, it is necessary to design special mitigation control algorithms for different flight environments and work tasks, which is costly. Since the control system requires the installation of multiple sets of active control mechanisms, the additional weight is large, and it is often suitable for large aircraft and difficult to apply to micro-aircraft. The rigid trailing edge has structural gaps and sudden changes in curvature, which makes it difficult to ensure the smooth change of aerodynamic force.

[0047] In view of the above technical problems, the embodiments of the present application provide a gust load mitigation device based on a micro-aircraft and a micro-aircraft, wherein the gust load mitigation device based on a micro-aircraft comprises a rigid frame, a flexible wing surface and a preload adjustment mechanism. The flexible wing surface is located on at least one side of the rigid frame, and the flexible wing surface is bonded to the rigid frame. The preload adjustment mechanism is used to adjust the shape of the flexible wing surface so that the flexible wing surface reaches a preset preload. The micro-aircraft comprises a main body and the above-mentioned gust load mitigation device based on a micro-aircraft. In this way, by setting up a gust load mitigation device based on a micro-aircraft and utilizing the unique advantages of the adaptive deformation of the flexible wing surface, the wing surface flow separation can be effectively suppressed, and while the time-averaged lift coefficient is increased, the lift coefficient pulsation can be reduced, thereby achieving gust load mitigation.

[0048] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of this application.

[0049] In the related art, the gust load mitigation device can be set up by a rigid trailing edge deflection method, a full-moving wingtip method, and a variable-camber flexible trailing edge method. Among them, the rigid trailing edge deflection method refers to offsetting the influence of gusts by deflecting the corresponding rigid trailing edge control surface (such as ailerons, elevators, etc.) to produce a lift change that is equal to the magnitude and opposite to the gust disturbance. This method requires the use of sensors such as direction, speed, and acceleration to detect the gust conditions in real time, and then output the control surface deflection signal through a pre-designed mitigation control law, and then achieve gust load mitigation of the wing and the aircraft by deflecting the control surface. The full-moving wingtip method is to connect the full-moving wingtip to the main wing before the aerodynamic center of the wing. When encountering vertical gusts, the full-moving wingtip lowers its head to produce a negative deflection, which reduces the effective angle of attack and reduces the lift caused by the vertical gusts, thereby achieving effective gust mitigation. The variable camber flexible trailing edge method is a wing gust mitigation method based on the variable camber flexible trailing edge. Through the aerodynamic reduction modeling and control scheme design, the variable camber trailing edge gust mitigation control is realized. Compared with the rigid wing control surface deflection method, this method uses the variable camber flexible trailing edge as the control surface, which can keep the aerodynamic surface smooth and continuous while continuously changing the camber, so that the aerodynamic force changes continuously and smoothly.

[0050] However, the gust load mitigation device in the related art has the following disadvantages:

[0051] Among them, in the gust load mitigation device using the rigid trailing edge deflection method and the variable curvature flexible trailing edge method, the control system includes sensors, control algorithms, control surfaces, etc., and the system structure is relatively complex. At the same time, it is necessary to design special mitigation control algorithms for different flight environments and work tasks, which is costly. It is also necessary to install multiple sets of active control mechanisms, which have a large additional weight and are difficult to apply to micro-aircraft. In addition, in the gust load mitigation device using the rigid trailing edge deflection method, there are structural gaps and curvature mutations in the rigid trailing edge. In the gust load mitigation device using the full-moving wingtip method, there is a structural gap between the full-moving wingtip and the main wing. Both are difficult to ensure the smooth change of aerodynamic force.

[0052] In summary, as an important component of an aircraft, the wing plays a vital role in the aerodynamic performance of the aircraft, but traditional rigid wings have become increasingly difficult to meet the needs of advanced aircraft to develop towards multi-task and high efficiency. Existing active gust load mitigation technologies (such as rigid trailing edge deflection method and variable curvature flexible trailing edge method) require the design of a special mitigation control algorithm, which is costly. Active control systems will increase the extra weight of the wing, which is difficult to meet the characteristics of micro-aircraft such as light weight and low cost. In addition, the speed of micro-aircraft is low, and the flight environment is generally in the atmospheric boundary layer near the ground, which belongs to the low Reynolds number category. Complex flow phenomena such as laminar separation and separation bubble rupture under low Reynolds numbers will cause the wing lift coefficient and lift-to-drag ratio to drop sharply, which requires the wing to have a good aerodynamic configuration. The existing full-moving wingtip method is difficult to ensure good aerodynamic performance due to the existence of structural gaps. Therefore, it is necessary to propose a gust load mitigation device suitable for micro-aircraft.

[0053] Therefore, in order to solve the above problems, the embodiment of the present application provides a gust load mitigation device based on a micro-aircraft and a micro-aircraft. By setting a gust load mitigation device based on a micro-aircraft, the unique advantage of the adaptive deformation of the flexible wing surface is utilized to effectively suppress the flow separation on the wing surface, and while increasing the time-averaged lift coefficient, the lift coefficient pulsation can be reduced to achieve gust load mitigation. The specific structure of the gust load mitigation device based on a micro-aircraft and the micro-aircraft provided in the embodiment of the present application is introduced below in conjunction with the accompanying drawings.

[0054] refer to Figure 1 as well as Figure 2In a first aspect, an embodiment of the present application provides a gust load mitigation device 100 based on a micro-aircraft, and the gust load mitigation device 100 based on a micro-aircraft may include a wing 200 and a preload adjustment mechanism 300. The wing 200 may further include a rigid frame 210 and a flexible wing surface 220. The flexible wing surface 220 may be located on at least one side of the rigid frame 210. In a possible implementation, the preload adjustment mechanism 300 can be used to adjust the preload of the flexible wing surface 220. After the flexible wing surface 220 is adjusted to a preset preload by the preload adjustment mechanism 300, the flexible wing surface 220 is connected to the rigid frame 210.

[0055] refer to Figure 3 , when the present embodiment is specifically implemented, the wing 200 may have a windward surface 230 and a leeward surface 240. Among them, the flexible wing surface 220 may have elastic deformation. In this way, the flexible wing surface 220 can deflect and deform toward the leeward surface 240 of the wing 200 through elastic deformation to increase lift and reduce gust loads. In the embodiment of the present application, since the flexible wing surface 220 has elastic deformation, under the action of aerodynamic loads, the flexible wing surface 220 can adaptively change its shape, and the kinematic characteristics of the flexible wing surface 220 are mainly manifested as time-averaged curvature and instantaneous vibration. In a possible implementation, when airflow flows through the flexible wing surface 220 at a positive angle of attack α, since there is always a pressure difference between the windward surface 230 and the leeward surface 240, the high pressure on the windward surface 230 and the low pressure on the leeward surface 240 will cause the flexible wing surface 220 to deflect and deform toward the leeward surface 240 of the wing 200, thereby generating a certain curvature, such as Figure 3 It can be understood that the change in camber caused by the pressure difference between the windward surface 230 and the leeward surface 240 makes the wing 200 more streamlined, thereby generating greater lift and a higher stall angle of attack.

[0056] refer to Figure 4 On the basis of the above embodiment, the flexible wing surface 220 may overlap with the rigid frame 210 on one side of the rigid frame 210, that is, the orthographic projection of the flexible wing surface 220 toward the rigid frame 210 covers the rigid frame 210. In a possible implementation, the flexible wing surface 220 may be located on at least part of the rigid frame 210, and the size of the flexible wing surface 220 on one side of the rigid frame 210 may also be less than or equal to the size of the rigid frame 210. This allows the flexible wing surface 220 to cover part of the rigid frame 210 on one side of the rigid frame 210. Of course, in some other embodiments, the flexible wing surface 220 may also be located on both sides of the rigid frame 210, so that the flexible wing surface 220 is respectively provided on the windward surface 230 and the leeward surface 240 of the wing 200.

[0057] In the embodiment of the present application, when the wing 200 encounters a vertical gust, the flexible wing surface 220 can produce adaptive deformation according to the strength of the gust, and the additional load caused by the gust is balanced by the change of tension inside the flexible wing surface 220. When the gust is strong, the traditional rigid wing is very likely to experience flow separation and stall, and the lift coefficient drops sharply. However, the wing 200 with a flexible wing surface 220 provided in the present application is easier to resist the flow separation caused by strong gusts due to the increase in curvature, and the lift coefficient changes more smoothly. Therefore, the adaptive deformation characteristics of the flexible wing surface 220 enable the flexible wing 200 to have a stronger ability to adapt to the environment than a rigid wing, and can be used to cope with gusts and the like.

[0058] Based on the above embodiment, the thickness of the flexible wing surface 220 can range from 0.2 mm to 2 mm, and the density can be 1.0 g / cm 3 , thereby reducing the weight of the flexible wing 220.

[0059] On the basis of the above-mentioned embodiment, the elastic modulus of the material of the flexible wing surface 220 can be in the range of 1MPa to 50MPa. It is understandable that the elastic modulus can be selected according to the specific work task and flight environment. In order to ensure the structural strength, the elastic modulus should not be too small. However, in order to enable the flexible wing surface 220 to produce sufficient deformation to cope with gusts, the elastic modulus should not be too large. Taking all factors into consideration, the elastic modulus of the material of the flexible wing surface 220 can be selected in the range of 1MPa to 50MPa, so that the flexible wing surface 220 can produce sufficient deformation to cope with gusts on the basis of ensuring the structural strength.

[0060] Based on the above embodiment, the material of the flexible wing surface 220 can be made of a polymer film, that is, the material of the flexible wing surface 220 can be a polymer film with an elastic modulus in the range of 1MPa to 50MPa. In the embodiment of the present application, the polymer film can be a thermoplastic polyurethane elastomer film or a polyvinyl chloride film.

[0061] On the basis of the above-mentioned embodiment, the flexible wing surface 220 and the rigid frame 210 can be connected by means of an adhesive. In the embodiment of the present application, the flexible wing surface 220 and the rigid frame 210 can be connected by using an organic silicone rubber adhesive. Among them, the organic silicone rubber adhesive has good stability, initial adhesion and sustained adhesion, which can not only ensure the bonding strength between the flexible wing surface 220 and the rigid frame 210, but also prevent the flexible wing surface 220 material from being corroded and failing. Of course, in some other embodiments, the flexible wing surface 220 and the rigid frame 210 can also be connected by riveting or heat shrinking fastening. Under the connection method of riveting or heat shrinking fastening, it is necessary to realize the fixed installation of the film skin of the flexible wing surface 220.

[0062] refer to Figure 5 Based on the above embodiment, the shape of the rigid frame 210 can be rectangular, elliptical, trapezoidal or triangular. The shape of the flexible wing surface 220 can be adjusted to match the rigid frame 210, that is, the shape of the flexible wing surface 220 can also be rectangular, elliptical, trapezoidal or triangular, so as to adapt to different shapes of the wing 200.

[0063] Continue to refer Figure 2 On the basis of the above embodiment, if the flexible wing surface 220 needs to be preloaded, the preload adjustment mechanism 300 can be used to stretch the flexible wing surface 220 to an elongated state. The preload adjustment mechanism 300 may include: a first clamp 310, a second clamp 320, a base 330, and a displacement platform 340. In a possible implementation, the first clamp 310 may be located on the base 330, and the second clamp 320 may be located on the displacement platform 340. The first clamp 310 can be used to clamp one end of the flexible wing surface 220, and the second clamp 320 can be used to clamp the other end of the flexible wing surface 220. Of course, in some other embodiments, the positions of the first clamp 310 and the second clamp 320 can be interchanged, that is, the first clamp 310 can be located on the displacement platform 340, and the second clamp 320 can be located on the base 330. In the embodiment of the present application, the positions of the first clamp 310 and the second clamp 320 are not limited. It is understandable that the translation stage 340 may have a knob 341 , and the flexible wing surface 220 may be stretched by adjusting the knob 341 of the translation stage 340 , so that the flexible wing surface 220 reaches a preset preload force.

[0064] On the basis of the above embodiment, when the flexible wing surface 220 reaches the preset preload, the flexible wing surface 220 is evenly bonded to the rigid frame 210 of the wing 200 using an adhesive. When the preload is large, the flexible wing surface 220 is closer to the rigid wing surface, and the deformation of the flexible wing surface 220 under the action of the aerodynamic load is small, which makes it easier for flow separation to occur. When the preload is small, the deformation of the flexible wing surface 220 under the action of the aerodynamic load is large, which makes it easier to suppress flow separation. However, the vibration amplitude of the flexible wing surface 220 is large at this time, which may lead to an increase in the pulsation of the lift coefficient. Therefore, the appropriate preload is selected based on the specific work tasks and flight environment.

[0065] Continue to refer Figure 5In a second aspect of the embodiment of the present application, a micro air vehicle 400 is provided, which may include a main body 410 and the above-mentioned gust load mitigation device 100 based on the micro air vehicle. The gust load mitigation device 100 based on the micro air vehicle may be connected to the main body 410. In a possible implementation, the gust load mitigation device 100 based on the micro air vehicle may be located on both sides of the main body 410.

[0066] In the embodiment of the present application, for example, the typical size parameters of the gust load mitigation device 100 based on a micro-aircraft are taken as an example. Among them, the overall span of the wing 200 can be 350mm, and the chord length can be 100mm. In a possible implementation, the length of the flexible wing surface 220 can be 320mm and the width can be 86mm. The material of the flexible wing surface 220 is polydimethylsiloxane with an elastic modulus of 1MPa, the thickness of the flexible wing surface 220 can be 0.2mm, and the density can be 1.01g / cm 3 Without applying preload force to the flexible wing 220, the flexible wing 220 is bonded to the rigid frame 210 by means of an organic silicone rubber adhesive. Aerodynamic force and flow field measurements are performed in a low-speed wind tunnel based on the above-mentioned actual size parameters. The free flow velocity is 7.5 m / s, and the Reynolds number based on the chord length is 5×10 4 The wind tunnel generates vertical gusts through a pair of periodically oscillating NACA0015 airfoils, with a gust frequency of 4 Hz and a gust ratio (ratio of vertical velocity to stream velocity) of about 0.06. In the embodiment of the present application, the aerodynamic force and flow field characteristics of the wing 200 with a flexible wing surface 220 and the rigid wing are compared.

[0067] In the embodiments of the present application, Figure 6 The lift coefficient curve is obtained by wind tunnel force test. Compared with the rigid wing, the present invention delays the model stall angle from 10° to about 19°, and the lift coefficient increases by 44.6% at most. Figure 7 The lift coefficient pulsation curve obtained from the test. Compared with the rigid wing, the present invention can significantly reduce the lift coefficient pulsation caused by gusts in the range of 0° to 10° attack angle. It can be seen that the adaptive deformation of the flexible wing surface 220 of the present invention can achieve gust load reduction at a small attack angle, and the lift coefficient pulsation can be reduced by 32% at most. Figure 8 2 is a time-averaged streamline diagram of the experimental test, from which it can be seen that, through the method proposed by the present invention, the flow separation of the flexible airfoil 220 on the wing 200 is suppressed, and the flow remains attached.

[0068] In the embodiments of the present application, Figure 7As shown in FIG. 1 , when the angle of attack is greater than 10°, the lift coefficient pulsation of the wing 200 with the flexible wing surface 220 is higher than that of the rigid wing. This is because the instantaneous vibration of the flexible wing surface 220 is significant, resulting in an increase in the unsteady pulsation of the lift coefficient. In practical applications, the vibration amplitude of the flexible wing surface 220 at a large angle of attack can be reduced by increasing the preload or selecting a flexible wing surface 220 with a larger elastic modulus, thereby expanding the angle of attack range of the gust load mitigation of the present invention.

[0069] In the embodiment of the present application, the present invention is based on the principle of adaptive deformation of the flexible wing surface 220. Compared with the existing active mitigation method of gust load, it can avoid the extra weight and high cost brought by the active control system, and has the advantages of light weight, low cost, simple structure, etc., which conforms to the characteristics of the micro-aircraft 400 being small, flexible, and low cost, and is suitable for the micro-aircraft 400. Secondly, the present invention can greatly reduce the gust load on the wing 200 at a small angle of attack (cruise state), and at the same time can ensure the smooth and continuous change of the shape of the wing 200, and can avoid the adverse effects such as flow separation caused by structural gaps and sudden changes in curvature, maintain the stable flight of the wing 200 and the micro-aircraft 400, and improve flight controllability and safety. In addition, while reducing gust loads, the present invention can effectively improve the time-averaged lift coefficient of the wing 200, reduce flow separation on the flexible wing surface 220, delay the stall of the wing 200, and overcome the adverse effects of complex flow phenomena such as laminar separation and separation bubble rupture under low Reynolds number conditions on the wing 200, which will contribute to the widespread application of the micro air vehicle 400 in military reconnaissance, environmental monitoring, emergency rescue and other aspects.

[0070] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0071] It should be noted that the phrases "in specific implementation", "in some embodiments", "in this embodiment", "exemplarily" and the like mentioned in the specification indicate that the described embodiment may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing specific features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments that are explicitly or not explicitly described.

[0072] In general, terms should be understood, at least in part, by the context in which they are used. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, depending, at least in part, on the context. Similarly, terms such as "a," "an," or "the" may also be understood to convey singular usage or to convey plural usage, depending, at least in part, on the context.

[0073] It should be easily understood that “on,” “above,” and “over” in the present disclosure should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above” or “over,” but also may include the meaning of “above” or “over something” with no intervening features or layers therebetween (i.e., directly on something).

[0074] In addition, spatially relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A gust load mitigation device based on a micro air vehicle, characterized in that: include: A wing, the wing comprising: a rigid frame and a flexible wing surface, the flexible wing surface being located on at least one side of the rigid frame; A preload adjustment mechanism, the preload adjustment mechanism is used to adjust the preload of the flexible wing surface, and the flexible wing surface is connected to the rigid frame when adjusted to a preset preload; The flexible airfoil overlaps the rigid frame on one side of the rigid frame; Or the flexible wing surface covers part of the rigid frame on one side of the rigid frame; Or the flexible wing surfaces are respectively located on both sides of the rigid frame; The preload force adjustment mechanism comprises: a first clamp, a second clamp, a base and a displacement platform; The first fixture is located on the base, and the second fixture is located on the translation platform; The first clamp is used to clamp one end of the flexible wing surface, and the second clamp is used to clamp the other end of the flexible wing surface; By adjusting the displacement stage to stretch the flexible wing surface, the flexible wing surface reaches a preset preload force; The translation platform is provided with a knob, and the flexible wing surface is stretched by adjusting the knob of the translation platform so that the flexible wing surface reaches a preset preload force; When the flexible wing surface reaches a preset preload force, the flexible wing surface is evenly bonded to the rigid frame of the wing using an adhesive, or the flexible wing surface is connected to the rigid frame by riveting or heat shrinking; The wing has a windward surface and a leeward surface; The flexible wing surface is elastic and can produce elastic deformation. Under the action of aerodynamic load, there is a pressure difference between the windward surface and the leeward surface of the wing, causing the flexible wing surface to deflect and deform toward the leeward surface of the wing through the elastic deformation, resulting in an increase in camber, so that the time-averaged lift of the wing is increased; When the wing encounters vertical gusts, the flexible wing surface produces adaptive deformation according to the strength of the gusts, and the additional load brought by the gusts is balanced by the change of tension inside the flexible wing surface; when the gusts increase, the curvature of the wing with the flexible wing surface increases, the ability to resist flow separation caused by gusts is enhanced, the pulsation of the lift coefficient is reduced, and the gust load is reduced.

2. The gust load mitigation device based on a micro air vehicle according to claim 1, characterized in that: The thickness of the flexible wing surface ranges from 0.2 mm to 2 mm.

3. The gust load mitigation device based on a micro air vehicle according to claim 1, characterized in that: The elastic modulus of the material of the flexible wing surface is in the range of 1 MPa to 50 MPa.

4. The gust load mitigation device based on a micro air vehicle according to claim 1, characterized in that: The material of the flexible wing surface is made of a high molecular polymer film; The high molecular polymer film is a thermoplastic polyurethane elastomer film or a polyvinyl chloride film.

5. The gust load mitigation device based on a micro air vehicle according to claim 1, characterized in that: The rigid frame is in the shape of a rectangle, an ellipse, a trapezoid or a triangle.

6. A micro aerial vehicle, characterized in that: It comprises a main body and the gust load mitigation device based on a micro air vehicle as described in any one of claims 1 to 5.

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