A structure-function integrated skin for airfoil variable thickness profile simulation and support

Abstract

An airfoil variable thickness profile simulation and support structure-function integrated skin belongs to the technical field of aviation wind tunnel test. It comprises a fixed base fixedly installed on an airfoil end plate, a front rotating beam and a front end of the fixed base are rotationally connected through a front rotating shaft, a rear rotating beam and a rear end of the fixed base are rotationally connected through a rear rotating shaft, a front translating beam and a rear translating beam are arranged between the front rotating beam and the rear rotating beam from front to rear, the front translating beam and the rear translating beam are respectively connected with the airfoil end plate through linear driving mechanisms, the front translating beam is connected with the front rotating beam through a front connecting rod mechanism, the rear translating beam is connected with the rear rotating beam through a rear connecting rod mechanism, and a silicone rubber skin is attached to the top of the front rotating beam, the front translating beam, the rear translating beam and the rear rotating beam. It has the advantages of high bearing capacity, high reliability and high integration, and through automatic and remote control variable thickness, the model unsteady aerodynamic performance wind tunnel test research is realized, so as to study or verify the time-varying aerodynamic performance of the variable thickness airfoil model.

Description

TECHNICAL FIELD

[0001] The present application relates to a structure-function integrated skin for airfoil variable thickness shape simulation and support, and belongs to the technical field of aviation wind tunnel test. BACKGROUND

[0002] With the rapid development of aerospace technology, the demand for lightweight, high-performance, multifunctional structures is increasing. Variable geometry wing technology breaks the limitations of traditional fixed wing design, and through the integration of bionics, intelligent materials and digital control, it realizes the qualitative leap of aircraft performance. Variable thickness wing is an important research direction in variable geometry wing. By deforming the skin on the surface of the wing, the relative thickness of the wing changes, thereby changing the aerodynamic shape of the wing. The wing shape is adjusted according to the flight state (such as cruising, taking off and landing, and maneuvering) to optimize the lift-drag ratio.

[0003] Variable thickness wings need a driver to apply driving force and driving stroke to change the thickness of the wing. The driving method is a key technology to realize shape change. Common mechanical driving is through motor, gear or lead screw to drive the deformation of the skin or internal support structure. This method has high reliability and strong carrying capacity, but the structure is complex, heavy, and mechanical clearance is easy to occur during movement. Adaptive support technology is a key subsystem for variable geometry wings to achieve efficient and reliable deformation. It adjusts the stiffness, shape or position of the support structure to adapt to different flight states. Currently, intelligent material-driven variable airfoil shape has become the mainstream. Flexible skin can realize seamless flap deformation, reduce airflow separation and turbulence, reduce resistance, maintain smooth and continuous wing surface, reduce turbulence, and improve laminar stability. However, the collaborative design of driving-structure-skin is difficult, and the rigidity control and deformation precision cannot be guaranteed. In the case of realizing large deformation, the material stiffness is often sacrificed, and a high-strength variable thickness wing structure cannot be obtained.

[0004] Therefore, it is urgent to provide a structure-function integrated skin for airfoil variable thickness shape simulation and support, which has the advantages of high carrying capacity, high reliability and high integration, and is suitable for variable thickness airfoil models in high-speed wind tunnels to solve the above technical problems. SUMMARY

[0005] The purpose of the present application is to provide a variable thickness airfoil model suitable for high-speed wind tunnels, which has the advantages of high carrying capacity, high reliability and high integration. Through automatic and remote control of variable thickness, non-steady aerodynamic performance wind tunnel test research is realized, so as to study or verify the time-varying aerodynamic performance of the variable thickness airfoil model. In the following, a brief summary of the present application is given to provide a basic understanding of some aspects of the present application. It should be understood that this summary is not an exhaustive summary of the present application. It is not intended to determine the key or important parts of the present application, nor to limit the scope of the present application.

[0006] The technical scheme of the present application:

[0007] A structure-function integrated skin of airfoil variable thickness profile simulation and support, comprising a front rotating beam, a front translating beam, a rear translating beam, a rear rotating beam, a fixed base, a silicone rubber skin, a front rotating shaft, an airfoil end plate, a rear rotating shaft, a front linkage mechanism, a rear linkage mechanism and a linear drive mechanism, the fixed base is fixedly installed on the airfoil end plate, the front end of the front rotating beam and the fixed base are rotationally connected through the front rotating shaft, the rear end of the rear rotating beam and the fixed base are rotationally connected through the rear rotating shaft, the front translating beam and the rear translating beam are arranged from front to rear between the front rotating beam and the rear rotating beam, the front translating beam and the rear translating beam are connected with the fixed base through the linear drive mechanism respectively, the front translating beam is connected with the front rotating beam through the front linkage mechanism, the rear translating beam is connected with the rear rotating beam through the rear linkage mechanism, and the silicone rubber skin is attached to the top of the front rotating beam, the front translating beam, the rear translating beam and the rear rotating beam.

[0008] Preferably, the front linkage mechanism comprises a front rotating beam connecting rod, a front two-force rod and a front translating beam connecting rod, the two ends of the front two-force rod are hinged to the front rotating beam connecting rod and the front translating beam connecting rod respectively, the front rotating beam connecting rod is fixedly connected with the front rotating beam, and the front translating beam connecting rod is fixedly connected with the front translating beam.

[0009] Preferably, the rear linkage mechanism comprises a rear translating beam connecting rod, a rear two-force rod and a rear rotating beam connecting rod, the two ends of the rear two-force rod are hinged to the rear translating beam connecting rod and the rear rotating beam connecting rod respectively.

[0010] Preferably, the front linkage mechanism is provided with multiple groups and is evenly distributed side by side.

[0011] Preferably, the rear linkage mechanism is provided with multiple groups and is evenly distributed side by side.

[0012] Preferably, the front translating beam and the rear translating beam are driven to move linearly in the vertical direction respectively and independently by the linear drive mechanism.

[0013] The linear motion of the front translating beam is transmitted and converted into the rotary motion of the front rotating beam through the front linkage mechanism, and the linear motion of the rear translating beam is transmitted and converted into the rotary motion of the rear rotating beam through the rear linkage mechanism.

[0014] The combination of the linear motion of the front translating beam and the rotary motion of the front rotating beam, and the combination of the linear motion of the rear translating beam and the rotary motion of the rear rotating beam, jointly change the intermediate thickness of the airfoil profile composed of the silicone rubber skin; wherein, during the variable thickness process, the silicone rubber skin deforms with the motion and always maintains the smoothness and continuity of the airfoil profile.

[0015] The present application has the following beneficial effects:

[0016] 1. The present application utilizes the combined motion of multiple four-bar linkages to convert single normal translation into a combination of translation and rotation, and uses a combination of rotating skin, translating skin and flexible skin to maintain high stiffness support throughout the process of airfoil variable thickness, while achieving the functions of airfoil variable thickness shape simulation and high stiffness support, and avoiding the great extrusion stress caused by chord length changes during the process of airfoil thickness change;

[0017] 2. The present application connects the flexible skin of silicone rubber to the rotating rigid skin and the translating rigid skin, to achieve gap sealing during the motion of rigid skin, and to achieve smooth and continuous transition of the airfoil shape during the process of airfoil variable thickness;

[0018] 3. The present application adjusts the sizes of the links in the four-bar linkage to obtain different airfoil section shapes during the process of variable thickness, and optimizes the variable thickness mode shapes for the target shape, thereby achieving high-precision airfoil variable thickness shape simulation. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a use state diagram of a structure-function integrated skin for airfoil variable thickness shape simulation and support;

[0020] Figure 2 is an assembly schematic diagram of the airfoil variable thickness flexible skin in the thick airfoil state described in the detailed description;

[0021] Figure 3 is an assembly schematic diagram of the airfoil variable thickness flexible skin in the thin airfoil state described in the detailed description;

[0022] Figure 4 is a structure exploded view of the front rotating beam;

[0023] Figure 5 is a structure exploded view of the front link mechanism;

[0024] Figure 6 is a structure exploded view of the rear link mechanism.

[0025] In the figure: 1 - front rotating beam, 2 - front translating beam, 3 - rear translating beam, 4 - rear rotating beam, 5 - fixed base, 6 - silicone rubber skin, 7 - front rotating shaft, 8 - front rotating beam connecting rod, 9 - front two-force rod, 10 - front translating beam connecting rod, 11 - rear translating beam connecting rod, 12 - rear two-force rod, 13 - rear rotating beam connecting rod, 14 - airfoil end plate, 15 - rear rotating shaft, 16 - front linkage mechanism, 17 - rear linkage mechanism, 18 - linear drive mechanism, 1-1 - front edge rotating plate, 1-2 - front edge cover plate, 5-1 - fixed base body, 5-2 - front edge fixed part, 5-3 - rear edge fixed part, 7-1 - first self-lubricating bearing, 7-2 - second self-lubricating bearing, 7-3 - third self-lubricating bearing, 7-4 - fourth self-lubricating bearing, 7-5 - fifth self-lubricating bearing, 7-6 - first screw, 7-7 - second screw, 7-8 - first circlip, 7-9 - second circlip, 7-10 - third circlip. DETAILED DESCRIPTION

[0026] In order to make the objects, technical solutions and advantages of the present application clearer and more comprehensible, the present application will be described below through specific embodiments shown in the drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0027] The connection mentioned in the present application is divided into fixed connection and detachable connection. The fixed connection (i.e. non-detachable connection) includes but is not limited to conventional fixed connection methods such as flange connection, rivet connection, adhesive connection and welding connection, and the detachable connection includes but is not limited to conventional detachable methods such as threaded connection, buckle connection, pin connection and hinge connection, and when the specific connection method is not specifically limited, at least one connection method can be found in the existing connection methods to realize the function, and the person skilled in the art can select it according to the needs. For example: the fixed connection selects welding connection, and the detachable connection selects hinge connection.

[0028] DETAILED DESCRIPTION Figures 1-6To illustrate the present embodiment, the structure-function integrated skin of the present embodiment for simulating and supporting a variable-thickness airfoil profile comprises a front rotating beam 1, a front translating beam 2, a rear translating beam 3, a rear rotating beam 4, a fixed base 5, a silicone skin 6, a front rotating shaft 7, an airfoil end plate 14, a rear rotating shaft 15, a front linkage mechanism 16, a rear linkage mechanism 17, and a linear drive mechanism 18. The fixed base 5 is mounted on the airfoil end plate 14 by means of fasteners such as bolts. The front rotating beam 1 is rotatably connected to the front end of the fixed base 5 by the front rotating shaft 7. The rear rotating beam 4 is rotatably connected to the rear end of the fixed base 5 by the rear rotating shaft 15. The front translating beam 2 and the rear translating beam 3 are arranged from front to rear between the front rotating beam 1 and the rear rotating beam 4. The front translating beam 2 and the rear translating beam 3 are respectively connected to the fixed base 5 by the linear drive mechanism 18. The front translating beam 2 is connected to the front rotating beam 1 by the front linkage mechanism 16. The rear translating beam 3 is connected to the rear rotating beam 4 by the rear linkage mechanism 17. The silicone skin 6 is attached to the top of the front rotating beam 1, the front translating beam 2, the rear translating beam 3, and the rear rotating beam 4. The core function of the silicone skin 6 in the variable-thickness process is to seal the gaps between the moving beams, ensuring that the airfoil profile can smoothly and continuously transition at any thickness, meeting the requirements of aerodynamic tests. The airfoil end plate 14 is fixed to the half-mold mounting wall plate of the supersonic wind tunnel, forming the installation base of the entire model in the wind tunnel. By cooperatively regulating the size and chordwise position of the front rotating beam 1, the front translating beam 2, the rear translating beam 3, the rear rotating beam 4, etc., the precise simulation and optimization of a series of intermediate profiles of the target airfoil during the variable-thickness process can be achieved, thereby accurately reproducing the designed airfoil.

[0029] The linear drive mechanism 18 is a linear motor or a linear electric push rod. One end of the linear drive mechanism 18 is mounted on the fixed base 5, and the other end acts on the front translating beam 2 or the rear translating beam 3, driving the front translating beam 2 or the rear translating beam 3 to achieve lifting movement. Using the principle of four-bar linkage mechanism, the lifting movement of the front translating beam 2 or the rear translating beam 3 drives the front rotating beam 1 or the rear rotating shaft 15 to rotate, and the silicone skin 6 is used for smooth transition, thereby achieving the functions of simulating and supporting the continuously smooth variable-thickness movement profile of the airfoil.

[0030] The fixed base 5 constitutes the static reference system of all moving parts, which includes a fixed base body 5-1, a leading edge fixed part 5-2, and a trailing edge fixed part 5-3. The leading edge fixed part 5-2 and the trailing edge fixed part 5-3 are respectively arranged on the front and rear sides of the fixed base body 5-1. The front rotating beam 1 is rotatably connected to the leading edge fixed part 5-2 of the fixed base 5 by the front rotating shaft 7. The rear rotating beam 4 is rotatably connected to the trailing edge fixed part 5-3 of the fixed base 5 by the rear rotating shaft 15.

[0031] Specifically, to achieve high-reliability rotation, the front rotating beam 1 adopts a split design, consisting of a front edge rotating plate 1-1 and a front edge cover plate 1-2. The front edge rotating plate 1-1 is connected to the front edge cover plate 1-2, which is fixed to the fixed base 5, via five front rotating shafts 7 and five self-lubricating bearings. The five self-lubricating bearings are designated as the first self-lubricating bearing 7-1, the second self-lubricating bearing 7-2, the third self-lubricating bearing 7-3, the fourth self-lubricating bearing 7-4, and the fifth self-lubricating bearing 7-5. The axial fixation of the front rotating shafts 7 is achieved by the first screw 7-6 and the second screw 7-7 at both ends and three retaining rings in the middle. The three retaining rings are the first retaining ring 7-8, the second retaining ring 7-9, and the third retaining ring 7-10. The rear rotating beam 4 adopts the same rotational connection principle and structural design.

[0032] The front linkage mechanism 16 includes a front rotating beam connecting rod 8, a front two-force rod 9, and a front translational beam connecting rod 10. The two ends of the front two-force rod 9 are respectively hinged to the front rotating beam connecting rod 8 and the front translational beam connecting rod 10. The front rotating beam connecting rod 8 is fixedly connected to the front rotating beam 1, and the front translational beam connecting rod 10 is fixedly connected to the front translational beam 2.

[0033] The rear linkage mechanism 17 includes a rear translation beam connecting rod 11, a rear two-force rod 12, and a rear rotating beam connecting rod 13. The two ends of the rear two-force rod 12 are respectively hinged to the rear translation beam connecting rod 11 and the rear rotating beam connecting rod 13, converting the linear motion of the rear translation beam 3 into the rotational motion of the rear rotating beam 4.

[0034] The front linkage mechanism 16 is provided in multiple sets, and is evenly distributed in parallel along the wingspan direction. In this embodiment, three sets are preferred, and the three sets of mechanisms work in parallel to jointly bear the load.

[0035] The rear linkage mechanism 17 is provided in multiple sets, and is evenly distributed in parallel along the wingspan direction. In this embodiment, three sets are preferred, and the three sets of mechanisms work in parallel to jointly bear the load.

[0036] The working process of this embodiment is as follows:

[0037] During wind tunnel testing, commands are sent to the electric cylinder via the ground control system:

[0038] 1. The electric cylinder starts and drives the front translation beam 2 and the rear translation beam 3 to move linearly in the vertical direction independently through the linear drive mechanism;

[0039] 2. The linear motion of the front translation beam 2 is transmitted through the front linkage mechanism 16 and converted into the rotational motion of the front rotating beam 1; the linear motion of the rear translation beam 3 is transmitted through the rear linkage mechanism 17 and converted into the rotational motion of the rear rotating beam 4.

[0040] 3. The middle thickness of the airfoil profile formed by the silicone rubber skin 6 is changed by the combination of the linear motion of the front translating beam 2 and the rotary motion of the front rotating beam 1, and the combination of the linear motion of the rear translating beam 3 and the rotary motion of the rear rotating beam 4;

[0041] 4. During the thickness changing process, the silicone rubber skin 6 deforms with the motion, and always maintains the smoothness and continuity of the airfoil profile. Figure 2 、 Figure 3 The airfoil thickness changeable compliant skin assembly schematic diagram of the thick airfoil and the thin airfoil respectively, high-rigidity support for realizing the thickness changing process is achieved by the combination of the rotating and translating motion, so that the airfoil thickness changeable profile simulation function is realized, and the structural support requirement of the airfoil thickness changeable process is adapted.

[0042] The present application solves the contradiction between the compliant deformation function and the high-rigidity support requirement of the airfoil thickness changeable skin by integrating the driving, transmission and support in the extremely small space, and provides a reliable technical basis for the wind tunnel test examination of the time-varying aerodynamic performance of the morphing aircraft.

[0043] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities according to the mathematical knowledge of arrangement and combination, so the present application does not explain the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present application.

[0044] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Those skilled in the art can make various changes and modifications to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A structural-functional integrated skin for simulating and supporting airfoil-shaped variable thickness, characterized in that: The structure includes a front rotating beam (1), a front translational beam (2), a rear translational beam (3), a rear rotating beam (4), a fixed base (5), a silicone rubber skin (6), a front rotating shaft (7), an airfoil end plate (14), a rear rotating shaft (15), a front linkage mechanism (16), a rear linkage mechanism (17), and a linear drive mechanism (18). The fixed base (5) is fixedly mounted on the airfoil end plate (14). The front ends of the front rotating beam (1) and the fixed base (5) are rotatably connected by the front rotating shaft (7), and the rear ends of the rear rotating beam (4) and the fixed base (5) are connected by the rear rotating shaft (15). The front rotating beam (1) and the rear rotating beam (4) are connected by a front translation beam (2) and a rear translation beam (3) from front to back. The front translation beam (2) and the rear translation beam (3) are connected to the fixed base (5) through a linear drive mechanism (18). The front translation beam (2) is connected to the front rotating beam (1) through a front linkage mechanism (16). The rear translation beam (3) is connected to the rear rotating beam (4) through a rear linkage mechanism (17). The silicone rubber skin (6) is attached to the top of the front rotating beam (1), the front translation beam (2), the rear translation beam (3) and the rear rotating beam (4).

2. The integrated structure-function skin for airfoil variable thickness shape simulation and support according to claim 1, characterized in that: The front linkage mechanism (16) includes a front rotating beam connecting rod (8), a front two-force rod (9) and a front translation beam connecting rod (10). The two ends of the front two-force rod (9) are hinged to the front rotating beam connecting rod (8) and the front translation beam connecting rod (10) respectively. The front rotating beam connecting rod (8) is fixedly connected to the front rotating beam (1), and the front translation beam connecting rod (10) is fixedly connected to the front translation beam (2).

3. The integrated structure-function skin for airfoil variable thickness shape simulation and support according to claim 2, characterized in that: The rear linkage mechanism (17) includes a rear translation beam connecting rod (11), a rear two-force rod (12), and a rear rotating beam connecting rod (13). The two ends of the rear two-force rod (12) are respectively hinged to the rear translation beam connecting rod (11) and the rear rotating beam connecting rod (13).

4. The integrated structure-function skin for airfoil variable thickness shape simulation and support according to claim 3, characterized in that: The front linkage mechanism (16) is provided in multiple sets, and is evenly distributed side by side.

5. The integrated structure-function skin for airfoil variable thickness shape simulation and support according to claim 4, characterized in that: The rear linkage mechanism (17) is provided in multiple sets, and is evenly distributed side by side.

6. The integrated structure-function skin for airfoil variable thickness shape simulation and support according to claim 5, characterized in that: The front translation beam (2) and the rear translation beam (3) are driven to move in a straight line in the vertical direction by the linear drive mechanism (18) respectively and independently; The linear motion of the front translation beam (2) is transmitted through the front linkage mechanism (16) and converted into the rotational motion of the front rotating beam (1); the linear motion of the rear translation beam (3) is transmitted through the rear linkage mechanism (17) and converted into the rotational motion of the rear rotating beam (4). The combination of the linear motion of the front translation beam (2) and the rotational motion of the front rotating beam (1), and the combination of the linear motion of the rear translation beam (3) and the rotational motion of the rear rotating beam (4), work together to change the intermediate thickness of the airfoil shape formed by the silicone rubber skin (6); wherein, during the thickening process, the silicone rubber skin (6) deforms with the motion, always maintaining the smoothness and continuity of the airfoil shape.

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