阅读说明：本技术 一种柔性前缘结构及其设计方法 (Flexible leading edge structure and design method thereof ) 是由 王志刚 杨宇 于 2020-04-09 设计创作，主要内容包括：本申请提供了一种柔性前缘结构,所述柔性前缘结构包括：柔性结构,用于形成机翼前缘的气动外形；以及多个驱动结构,分布式设置在所述柔性结构的内部,在激励信号的激励下能够产生驱动力,所述驱动力作用于所述柔性结构以改变所述柔性结构的气动外形。本申请提供的柔性前缘结构同现有的变弯度机翼前缘装置相比,一方面,可以实现结构与功能的真正一体化,驱动结构不仅作为驱动器,同时还能够作为承载结构,可以有效的降低结构复杂性,降低重量,提高飞机综合性能；另一方面,通过分布式设置的多个驱动机构能够提高变形精度,可以进一步实现多个目标外形的变形控制,真正实现前缘外形的实时优化。(The present application provides a flexible leading edge structure, comprising: a flexible structure for forming an aerodynamic profile of the leading edge of the airfoil; and the driving structures are distributed in the flexible structure and can generate driving force under the excitation of an excitation signal, and the driving force acts on the flexible structure to change the pneumatic appearance of the flexible structure. Compared with the existing variable camber wing leading edge device, on one hand, the flexible leading edge structure can realize the real integration of the structure and the function, and the driving structure not only can be used as a driver, but also can be used as a bearing structure, so that the structural complexity can be effectively reduced, the weight can be reduced, and the comprehensive performance of an airplane can be improved; on the other hand, the deformation precision can be improved through the plurality of driving mechanisms arranged in a distributed mode, the deformation control of a plurality of target shapes can be further realized, and the real-time optimization of the front edge shape is really realized.)

1. A flexible leading edge structure, comprising:

a flexible structure for forming an aerodynamic profile of the leading edge of the airfoil; and

and the driving structures are distributed in the flexible structure and can generate driving force under the excitation of the excitation signal, and the driving force acts on the flexible structure to change the pneumatic shape of the flexible structure.

2. The flexible leading edge structure of claim 1, wherein the flexible structure is made of a metallic material or a resin material.

3. The flexible leading edge structure of claim 1, wherein the driving mechanism is one or more of a shape memory alloy, a piezoelectric stack, a piezoelectric fiber composite, or a pneumatic muscle tube.

4. The flexible leading edge structure of claim 1, further comprising an excitation device coupled to the drive mechanism for generating a signal for exciting movement of the drive mechanism.

5. The flexible leading edge structure of claim 1, further comprising a flexible skin disposed on an outer surface of the flexible structure.

6. The flexible leading edge structure of claim 1, wherein the flexible leading edge structure is fabricated by a 4D additive manufacturing method.

7. A design method for implementing a flexible leading edge structure as claimed in any one of claims 1 to 6, said design method comprising:

obtaining the aerodynamic performance requirements of wings under various flight conditions according to the overall requirements of the airplane;

optimizing an initial profile of a leading edge of the airfoil and a target profile of at least one state according to aerodynamic performance requirements of the airfoil;

constructing a finite element model of the flexible structure, and carrying out finite element meshing on the flexible structure, wherein the driving structure is constructed into a beam unit or a shell unit, and the flexible structure and the driving structure are coupled through multi-point driving constraint so as to realize force transmission;

and taking the target shape as an optimization target, and performing collaborative optimization design on the topology of the flexible structure and the parameters of the driving structure so as to realize accurate shape control, wherein the parameters of the driving structure comprise the position, the installation angle, the geometric length and the driving force of the driving structure.

8. The method of designing a flexible leading edge structure of claim 7, wherein said flight conditions include aircraft cruise, aircraft takeoff, aircraft landing.

9. The method of designing a flexible leading edge structure of claim 7, wherein the method further comprises:

and manufacturing the flexible leading edge structure, and verifying whether the deformation of the flexible leading edge structure meets the target appearance requirement through a test.

Technical Field

The application belongs to the technical field of aerodynamic design of wings, and particularly relates to a flexible leading edge structure and a design method thereof.

Background

The traditional wing can only ensure the optimal aerodynamic efficiency in a cruising state, and in order to meet the aerodynamic requirements under other working conditions, the traditional wing usually realizes the change and adjustment of the aerodynamic shape by a leading edge high lift device based on a rigid hinge. However, the conventional leading edge flap often has gaps, so that the aerodynamic surface is discontinuous, the friction between a sharp part of the structure and air is increased, and the noise of takeoff and approach landing is increased.

In order to realize the continuous and accurate deformation control of the front edge of the deformable wing, various continuous variable camber front edge structures are proposed at home and abroad at present, but the structures are basically based on the structural type of a rigid mechanism or a semi-rigid mechanism, and the problems of complex structure, heavy weight, low reliability and the like exist.

Disclosure of Invention

It is an object of the present application to provide a flexible leading edge structure and a method of designing the same to address any of the above problems.

In one aspect, the technical solution provided by the present application is: a flexible leading edge structure, the flexible leading edge structure comprising:

a flexible structure for forming an aerodynamic profile of the leading edge of the airfoil; and

and the driving structures are distributed in the flexible structure and can generate driving force under the excitation of the excitation signal, and the driving force acts on the flexible structure to change the pneumatic shape of the flexible structure.

In a preferred embodiment of the present application, the flexible structure is made of a metal material or a resin material.

In a preferred embodiment of the present application, the driving mechanism is one or more of a shape memory alloy, a piezoelectric stack, a piezoelectric fiber composite material, or a pneumatic muscle tube.

In a preferred embodiment of the present application, the flexible leading edge structure further comprises an excitation device connected to the drive mechanism for generating a signal for exciting the drive mechanism to move.

In a preferred embodiment of the present application, the flexible leading edge structure further comprises a flexible skin, the flexible skin being arranged at an outer surface of the flexible structure.

In a preferred embodiment of the present application, the flexible leading edge structure is made by a 4D additive manufacturing method.

On the other hand, the technical scheme provided by the application is as follows: a design method for implementing a flexible leading edge structure as in any above, the design method comprising:

s1, obtaining the aerodynamic performance requirements of the wings under various flight conditions according to the overall requirements of the airplane;

s2, optimizing the initial profile of the wing leading edge and the target profile of at least one state according to the aerodynamic performance requirement of the wing;

s3, constructing a finite element model of the flexible structure, and carrying out finite element mesh division on the flexible structure, wherein the driving structure is constructed into a beam unit or a shell unit, and the flexible structure and the driving structure are coupled through multi-point driving constraint to realize force transmission;

and S4, taking the target shape as an optimization target, and performing cooperative optimization design of the shape topology of the flexible structure and the driving structure parameters to realize accurate shape control, wherein the driving structure parameters comprise the position, the installation angle, the geometric length and the driving force of the driving structure.

In a preferred embodiment of the present application, the flight conditions include aircraft cruise, aircraft takeoff, and aircraft landing.

In a preferred embodiment of the present application, the method further comprises: and manufacturing the flexible leading edge structure, and verifying whether the deformation of the flexible leading edge structure meets the target appearance requirement through a test.

Compared with the existing camber-variable wing leading edge device, the flexible leading edge structure and the design method thereof can realize the real integration and intellectualization of the flexible leading edge and can realize the accurate control of a plurality of continuous target shapes: on one hand, the flexible structure and the driving structure are integrally processed and manufactured, so that the structure and the function are really integrated, the driving structure not only serves as a driver, but also serves as a bearing structure, the structural complexity can be effectively reduced, the weight is reduced, and the comprehensive performance of the airplane is improved; on the other hand, the flexible leading edge structure can realize self-adaptive accurate control on the shape of the leading edge of the wing, the deformation precision can be improved through the plurality of driving mechanisms arranged in a distributed mode, the deformation control of a plurality of target shapes can be further realized through the distributed driving mechanisms through the cooperative control system, and real-time optimization of the leading edge shape is really realized.

Drawings

In order to more clearly illustrate the technical solutions provided by the present application, the following briefly introduces the accompanying drawings. It is to be expressly understood that the drawings described below are only illustrative of some embodiments of the invention.

FIG. 1 is a schematic illustration of an original version of a flexible leading edge structure in an embodiment of the present application;

FIG. 2 is a schematic illustration of an initial profile and a target profile of a flexible leading edge structure in an embodiment of the present application;

fig. 3 is a schematic diagram of a scheme of cooperative topology optimization of a flexible leading edge structure in an embodiment of the present application.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application.

In order to achieve the goal of seamless, smooth and continuous deformability of flexible leading edges in the prior art, the present application proposes a flexible leading edge structure based on a distributed drive structure and a design method thereof. In the scheme of this application, through the distributed drive structure that sets up in flexible construction, through the collaborative optimization that drive structure drive flexible construction warp, realize the accurate control of pneumatic appearance.

The flexible leading edge structure provided by the application comprises a flexible structure 1 and a plurality of driving structures 21-23, wherein the flexible structure 1 roughly forms the structural aerodynamic shape of the leading edge of the wing, the driving structures 21-23 are distributed in the flexible structure, the driving structures 21-23 can be controlled to act to generate driving force by exciting the driving structures 21-23, for example, the extending action can be realized, the flexible structure 1 is driven to deform by the generated driving force contacting the flexible structure 1, and the generated deformation can form the aerodynamic shape required by the leading edge of the wing.

In the present application, the flexible structure 1 may be made of a metal material or a resin material, etc., i.e., may form a smooth and continuous aerodynamic shape, and thus has a certain shape retention capability.

In the application, the driving structure may be a block or a rod made of shape memory alloy or piezoelectric fiber composite material, or may be one or a combination of several of pneumatic muscle tubes and other products. For example, the driving structure may be a rod-shaped device made of a shape memory alloy material, or the driving structure may be a piezoelectric fiber composite material, or both the driving structure made of the shape memory alloy material and the pneumatic muscle tube product are used as the driving structure for driving.

It should be noted that the number of driving structures shown in fig. 1 is only an illustration, and may be increased or decreased as needed in the actual use or design process, for example, two, four or more. It will be appreciated that excessive drive configurations may result in increased weight at the leading edge of the wing, and therefore should be used to the extent possible, based on the ability to deform the leading edge.

In this application, the flexible leading edge structure further comprises an excitation device connected to the drive mechanism for generating a signal for exciting movement of the drive mechanism to control the drive mechanism.

In the present application, the flexible leading edge structure may or may not include a skin. When the flexible structure comprises the skin, the skin adopts a flexible skin which is arranged on the outer surface of the flexible structure; when it does not comprise a skin, the flexible structure 1 itself may be made of a corrosion-resistant flexible material to fulfill the function of the skin.

In addition, the present application also provides a design method for implementing the above-mentioned flexible leading edge structure, and the design method of the present application includes:

s1, obtaining the aerodynamic performance requirements of the wings under various flight conditions according to the overall requirements of the airplane; for example, flight conditions may include aircraft cruise, aircraft takeoff, aircraft landing, and the like.

S2, optimizing the initial profile of the wing leading edge and the target profile of at least one state according to the aerodynamic performance requirement of the wing;

s3, constructing a finite element model of the flexible structure, and carrying out finite element mesh division on the flexible structure, wherein the driving structure is constructed into a beam unit or a shell unit, and the flexible structure and the driving structure are coupled through multi-point driving constraint to realize force transmission;

and S4, taking the target shape as an optimization target, and performing collaborative optimization design on the topology of the flexible structure and the parameters of the driving structure, so as to realize accurate shape control, wherein the parameters of the driving structure comprise the position, the installation angle, the geometric length and the driving force of the driving structure.

In addition, the design method of the present application further includes the steps of: taking the obtained design result as input, and carrying out integrated processing on the flexible structure and the driving structure in a 4D additive printing manufacturing mode; and then testing the flexible leading edge structure of the wing with variable camber through a test to determine whether the deformation meets the target appearance requirement.

In the method, the flexible front edge structure is modeled, finite element meshing is carried out on the flexible structure, the driving structure and the flexible structure are coupled through multi-point constraint, driving force is transmitted to the flexible structure, the flexible structure is integrally deformed, and then in order to enable the surface of the flexible structure to achieve an accurate target appearance, the appearance of the flexible structure is subjected to collaborative optimization design through a plurality of design variables such as topology and driving structure parameters, and the like, so that accurate appearance control is achieved.

Referring to the embodiment drawings shown in fig. 1 to 3, since the deformable wing leading edge is generally moved from the initial position to the target position, the embodiment drawings of the present application are optimized by using the droop action of the flexible leading edge structure as the optimization target.

Fig. 1 shows a schematic diagram of an original scheme of a flexible leading edge structure, in which a flexible structure 1 is filled with a gap between a driving structure and the flexible leading edge structure; the optimal design objective of the flexible leading edge structure shown in FIG. 2, wherein the solid line represents the initial state of the aerodynamic profile (e.g., the profile of the leading edge of the wing when the aircraft is cruising), and the dotted line represents the target state of the aerodynamic profile (e.g., the profile of the leading edge of the wing when the aircraft is landing); by performing the cooperative optimization of the topology of the shape of the flexible structure 1 and the parameters such as the position, the installation angle, the geometric length, the magnitude of the driving force and the like of the driving structure, the comprehensive topology scheme of the flexible leading edge structure integrated with a plurality of driving structures can be finally determined, as shown in fig. 3.

It should be noted that in this embodiment, the initial position moves downward to the target position to perform the collaborative optimization design, and the initial position moves upward to the target position to perform the collaborative optimization design according to needs, which is not described herein.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.