High-speed wind tunnel airfoil variable thickness model mechanism

Abstract

The high-speed wind tunnel airfoil variable thickness model mechanism belongs to the field of aviation wind tunnel test technology. The present invention is to solve the problems of existing variable thickness models and mechanisms such as large volume, weak load-bearing capacity, and low reliability. It includes a variable thickness model and two sets of transmission mechanisms; the variable thickness model is divided into a fixed part and a flexible skin, the flexible skin and the fixed part form a streamlined hollow airfoil body, the driving end of the transmission mechanism is a horizontally arranged electric cylinder, the output end is an active beam that slides up and down, the flexible skin is connected to the active beam, the piston rod of the electric cylinder is horizontally extended and retracted, and converted into the lifting movement of the flexible skin, so as to realize the thickness range of the variable thickness model of 0mm to 15mm adjustment, and the cross-sectional shape of the wing variable thickness model can be controlled online in real time during the wind tunnel blowing process, providing support for the wind tunnel test research on the unsteady aerodynamic performance of variable thickness aircraft in high-speed wind tunnels.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation wind tunnel testing, and is used for research on wind tunnel testing of unsteady aerodynamic characteristics of variable thickness wings, in particular to a variable thickness model mechanism of a high-speed wind tunnel airfoil. Background Art

[0002] With the rapid development of aerospace technology, modern aircraft operate at various speeds, such as subsonic, transonic, and supersonic. This places increasingly stringent demands on aircraft aerodynamic performance, making it difficult for aircraft to simultaneously maintain good maneuverability, low-speed takeoff and landing capabilities, and fuel economy. Variable-thickness aircraft can control lift and drag characteristics by varying airfoil thickness to adapt to the aerodynamic requirements at different speeds. To investigate the aerodynamic performance of variable-thickness aircraft, wind tunnel tests on unsteady aerodynamic characteristics of variable-thickness models were conducted. The development of a real-time, remotely controlled wind tunnel test model and mechanism for variable-thickness airfoils is of great significance.

[0003] Current variable-thickness wing drive mechanisms primarily include multi-link mechanisms, curved disc structures, and distributed drive mechanisms, all of which can, in principle, achieve variable thickness for the wing profile. Multi-link mechanisms require fewer drive units and have a simpler structure, but they suffer from poor load-bearing capacity, lack linearity in the thickness variation process, and struggle to maintain control over the intermediate thickness variation of the airfoil. Multiple curved discs combined with chord-wise rotating shafts offer greater control flexibility, allowing for multi-point control of the airfoil thickness variation process by designing the shape of each curved disc. However, for wind tunnel test models with limited space and size, it is difficult to simultaneously integrate the drive unit and transmission mechanism. Distributed drive mechanisms employ shape memory alloys, piezoelectric materials, or distributed motors, offering multiple degrees of freedom in variable-thickness airfoil drive. However, these mechanisms also suffer from complex drive structures, poor reliability using smart materials, and space-consuming distributed motors with low output energy density.

[0004] Therefore, existing structural solutions for variable-thickness wing models and mechanisms for high-speed wind tunnels struggle to simultaneously address the miniaturization, high load-bearing capacity, high reliability, and linear output capabilities required by high-speed wind tunnels. With the advancement of aerospace technology, wind tunnel testing of the aerodynamic characteristics of various variant aircraft needs to be rapidly advanced, and the structural technology supporting these tests is in urgent need of improvement. Therefore, resolving the challenges of variable-thickness structural technology and drive technology for high-speed wind tunnel airfoils is urgent. Summary of the Invention

[0005] To address the aforementioned technical issues, the present invention provides a variable-thickness airfoil model mechanism suitable for high-speed wind tunnels. This mechanism offers advantages such as high load-bearing capacity, high reliability, and high integration. By automatically and remotely controlling the thickness of the airfoil, wind tunnel tests can be conducted to investigate the unsteady aerodynamic performance of the model, thereby studying or verifying the time-varying aerodynamic performance of the variable-thickness airfoil model. The technical solutions employed by the present invention are as follows:

[0006] A high-speed wind tunnel airfoil variable thickness model mechanism, comprising a variable thickness model and two sets of transmission mechanisms;

[0007] The variable thickness model is divided into a fixed part and a flexible skin. The transmission mechanism includes an input beam, an output beam and a crankshaft. The crankshaft is rotatably arranged on the fixed part. The input end slider and the output end slider respectively slide along the diameter of the crankshaft, and the sliding paths of the input end slider and the output end slider form an angle. The input beam is hinged to the input end slider, and the output beam is hinged to the output end slider.

[0008] The active beam is arranged to slide vertically, the output beams of the two sets of transmission mechanisms are connected to the two active beams respectively, the front and rear parts of the flexible skin are connected to the two active beams respectively, the electric cylinder is installed on the fixed part, one end of the two horizontally arranged transmission shafts is connected to the piston rods of the two electric cylinders respectively, and the other ends pass through the fixed part and are connected to the two input beams respectively;

[0009] The fixed part is connected to the front end of the balance support rod through a force measuring balance.

[0010] Furthermore, the fixed part includes a leading edge, a lower base plate, a trailing edge, a wing tip plate and a wing root end plate. The flexible skin, the leading edge, the lower base plate and the trailing edge are sequentially combined to form a streamlined hollow airfoil body. The wing tip plate and the wing root end plate correspondingly close the openings at both ends of the hollow airfoil body.

[0011] Furthermore, the crankshaft is rotatably arranged on the lower base plate through a bearing seat.

[0012] Furthermore, the electric cylinder is mounted on the wing root end plate through a support sleeve.

[0013] Furthermore, one end of the transmission shaft passes through the support sleeve and is connected to the piston rod of the corresponding electric cylinder, and the other end passes through the wing root end plate and is connected to the corresponding input beam.

[0014] Furthermore, a sliding support is provided on the lower base plate, and the transmission shaft is in sliding cooperation with the sliding support.

[0015] Furthermore, the input beam and the input end slider are hinged via the input end rotating shaft.

[0016] Furthermore, the output beam and the output end slider are hinged via the output end rotating shaft.

[0017] Furthermore, it also includes an active beam sliding module, which includes a vertical guide rail group and a guide slider group that slide together. The vertical guide rail group is fixed to the lower base plate through a guide rail support, and the two active beams are respectively connected to the guide slider groups of the two active beam sliding modules.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention integrates two independent transmission mechanisms within a 0.6m-scale, 65mm airfoil thickness model, enabling the airfoil thickness to vary in the range of 0mm to 15mm. This approach has high space utilization and allows for real-time online control of the cross-sectional shape of the variable-thickness wing model during wind tunnel blowing, providing support for wind tunnel test research on the unsteady aerodynamic performance of variable-thickness aircraft in high-speed wind tunnels.

[0020] 2. The electric cylinder of the present invention is externally located and transmits power to the interior of the variable thickness model through a transmission shaft. Two high-load electric cylinders are supported on one side of the wing root end plate by a support sleeve and do not contact the internal structure of the wind tunnel wall panel. Only a force balance is used as the load transfer medium between the variable thickness model and the wind tunnel. This enables the wing variable thickness model and wind tunnel mechanism to have a high load-bearing capacity in an extremely small space, while avoiding the additional support stiffness brought by the electric cylinder support on the wind tunnel mechanism, which affects the force measurement.

[0021] 3. The transmission mechanism of the present invention utilizes a transmission mechanism composed of a crankshaft, a slider, and a rotating shaft to convert the longitudinal motion of the electric cylinder into normal motion, greatly improving the internal space utilization of the variable-thickness wing model. The transmission has good load-bearing capacity, reliability, and linear output capability, solving the contradiction between space and load in the variable-thickness wind tunnel test model. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is an axonometric drawing of the present invention;

[0023] Figure 2 It is a schematic diagram of the thin airfoil state of the variable thickness model;

[0024] Figure 3 It is a schematic diagram of the thick airfoil state of the variable thickness model;

[0025] Figure 4 This is a schematic diagram of the corresponding crankshaft state when the variable thickness model is in the thin airfoil state;

[0026] Figure 5 This is a schematic diagram of the corresponding crankshaft state when the variable thickness model is in the thick airfoil state;

[0027] Figure 6 It is a structural diagram of the transmission mechanism;

[0028] Figure 7 It is a schematic diagram of the connection between the electric cylinder and the dynamometer and the wing root end plate of the present invention.

[0029] In the figure, 1. Electric cylinder, 2. Balance support rod, 3. Support sleeve, 4. Drive shaft, 5. Transmission mechanism, 5-1. Input beam, 5-2. Output beam, 5-3. Bearing seat, 5-4. Input end slider, 5-5. Input end rotating shaft, 5-6. Output end slider, 5-7. Output end rotating shaft, 5-8. Crankshaft, 6. Lower base plate, 7. Dynamometer, 8. Active beam, 9. Sliding support, 10. Wing tip plate, 11. Wing root plate, 12. Leading edge, 13. Trailing edge, 14. Flexible skin. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention is described below using specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0031] The connections mentioned in the present invention are divided into fixed connections and detachable connections. The fixed connection refers to a non-detachable connection, including but not limited to conventional fixed connection methods such as hem connection, rivet connection, adhesive connection, and welding connection. The detachable connection refers to but not limited to conventional detachable connection methods such as bolt connection, snap connection, pin connection, and hinge connection. When the specific connection method is not clearly specified, it is assumed that at least one connection method can be found among the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs. For example, a welded connection is selected for a fixed connection, and a bolted connection is selected for a detachable connection.

[0032] The present invention will be further described in detail below with reference to the accompanying drawings. The following embodiments are provided to explain the present invention, but the present invention is not limited to the following embodiments.

[0033] Example: Figures 1 to 7 As shown, the variable thickness model mechanism of the high-speed wind tunnel airfoil is particularly suitable for a variable thickness airfoil model suitable for a 0.6m-level high-speed wind tunnel, including a drive system, a transmission system, a model body and a support system, including a variable thickness model and two sets of transmission mechanisms 5;

[0034] The variable thickness model is divided into a fixed part and a deformable part. The fixed part includes a leading edge 12, a lower bottom plate 6, a trailing edge 13, a wing tip plate 10, and a wing root end plate 11. The deformable part is a flexible skin 14. The flexible skin 14, the leading edge 12, the lower bottom plate 6, and the trailing edge 13 are sequentially enclosed to form a streamlined hollow airfoil. The wing tip plate 10 and the wing root end plate 11 correspondingly close the openings at both ends of the hollow airfoil.

[0035] The transmission mechanism 5 includes an input beam 5-1, an output beam 5-2, a bearing seat 5-3, an input end slider 5-4, an output end slider 5-6, and a crankshaft 5-8. The crankshaft 5-8 is rotatably mounted on the lower base plate 6 via the bearing seat 5-3. A first protrusion and a second protrusion are radially arranged on the crankshaft 5-8. The first protrusion and the second protrusion form an angle. The input end slider 5-4 slides with the first protrusion. The input beam 5-1 is hingedly connected to the input end slider 5-4. The output end slider 5-6 slides with the second protrusion. The output beam 5-2 is hingedly connected to the output end slider 5-6.

[0036] The active beam sliding module 15 includes a vertical guide rail group and a guide slider group that slide together. The vertical guide rail group is fixed to the lower base plate 6 via a guide rail support 16. The two active beams 8 are respectively connected to the guide slider groups of the two active beam sliding modules 15. The two output beams 5-2 are respectively connected to the two active beams 8. The front and rear parts of the flexible skin 14 are respectively connected to the two active beams 8. The two electric cylinders 1 are both mounted on the wing root end plate 11 through the support sleeve 3. One end of the two horizontally arranged transmission shafts 4 passes through the support sleeve 3 and is respectively connected to the piston rods of the two electric cylinders 1. The other ends of the two transmission shafts 4 pass through the wing root end plate 11 and are respectively connected to the two input beams 5-1.

[0037] The wing root end plate 11 is connected to one end of the balance rod 2 through the force measuring balance 7, and the other end of the balance rod 2 is connected to the internal structure of the wind tunnel wall panel. The electric cylinder 1 uses the internal space of the wind tunnel wall panel without contacting its internal structure.

[0038] The leading edge 12, trailing edge 13 and lower base plate 6 of the variable thickness model are fixed, and the flexible skin 14 is independently supported by two active beams 8 and moves up and down to realize the variable thickness process of the variable thickness model. The variable thickness model is installed on the supersonic wind tunnel half-mold mounting wall panel. Each group of independently working transmission mechanisms 5 is driven by an electric cylinder 1 and is matched with a transmission system composed of crankshafts 5-8, sliders and rotating shafts to realize the up and down variable thickness movement of the flexible skin 14. The movable skin part of the model adopts the flexible skin 14 to achieve deformation and load-bearing requirements. The two electric cylinders 1 are installed inside the wind tunnel half-mold mounting wall panel and connected to the wing root end plate 11 through the support sleeve 3.

[0039] The electric cylinder 1 drives the transmission shaft 4 to extend and retract horizontally, thereby driving the input beam 5-1 to move horizontally. When the input beam 5-1 moves horizontally, it drives the input end slider 5-4 to slide on the first protrusion and rotates the crankshaft 5-8, so that the output end slider 5-6 can slide on the second protrusion, and then drive the flexible skin 14 to rise and fall through the active beam 8, realizing the conversion of horizontal linear motion to vertical motion to change the thickness of the model.

[0040] The present invention has the following beneficial effects:

[0041] 1. The present invention integrates two independent transmission mechanisms 5 within a 0.6m-scale, 65mm airfoil thickness model, enabling the airfoil thickness to vary within a range of 0mm to 15mm. This provides high space utilization and allows for real-time online control of the cross-sectional shape of the variable-thickness wing model during wind tunnel blowing, providing support for wind tunnel test research on the unsteady aerodynamic performance of variable-thickness aircraft in high-speed wind tunnels.

[0042] 2. The electric cylinder 1 of the present invention is externally located and transmits power to the interior of the variable thickness model through the transmission shaft 4. Two high-load electric cylinders 1 are supported on one side of the wing root end plate 11 by the support sleeve 3 and do not contact the internal structure of the wind tunnel wall panel. Only the force balance 7 is used as the load transmission medium between the variable thickness model and the wind tunnel. This enables the wing variable thickness model and the wind tunnel mechanism to have a high load-bearing capacity in an extremely small space, while avoiding the additional support stiffness caused by the electric cylinder 1 supported on the wind tunnel mechanism, which affects the force measurement.

[0043] 3. The transmission mechanism 5 of the present invention converts the longitudinal motion of the electric cylinder 1 into normal motion by utilizing a transmission mechanism consisting of crankshafts 5-8, sliders, and a rotating shaft, thereby greatly improving the internal space utilization of the variable-thickness wing model. The transmission has good load-bearing capacity, reliability, and linear output capability, thus resolving the contradiction between space and load in the variable-thickness wind tunnel test model.

[0044] A sliding support 9 is provided on the lower base plate 6 , and the transmission shaft 4 is slidably matched with the sliding support 9 , and the sliding support 9 provides a sliding guide for the transmission shaft 4 .

[0045] The input beam 5-1 and the input end slider 5-4 are hinged through the input end rotating shaft 5-5.

[0046] The output beam 5-2 and the output end slider 5-6 are hinged through the output end rotating shaft 5-7.

[0047] The above embodiments are merely illustrative of the present invention and do not limit its scope of protection. Those skilled in the art may make partial changes thereto, which are within the scope of protection of the present invention as long as they do not exceed the spirit of the present invention.

Claims

1. High-speed wind tunnel airfoil variable thickness model mechanism, characterized by: It includes a variable thickness model and two sets of transmission mechanisms (5); The variable thickness model is divided into a fixed part and a flexible skin (14); the transmission mechanism (5) includes an input beam (5-1), an output beam (5-2) and a crankshaft (5-8); the crankshaft (5-8) is rotatably arranged on the fixed part; the input end slider (5-4) and the output end slider (5-6) respectively slide along the radial direction of the crankshaft (5-8); and the sliding paths of the input end slider (5-4) and the output end slider (5-6) form an angle; the input beam (5-1) is hinged to the input end slider (5-4), and the output beam (5-2) is hinged to the output end slider (5-6); The active beam (8) is arranged to slide vertically, the output beams (5-2) of the two sets of transmission mechanisms (5) are connected to the two active beams (8) respectively, the front and rear parts of the flexible skin (14) are connected to the two active beams (8) respectively, the electric cylinder (1) is installed on the fixed part, and one end of two horizontally arranged transmission shafts (4) is connected to the piston rods of the two electric cylinders (1) respectively, and the other end passes through the fixed part and is connected to the two input beams (5-1) respectively; The fixed part is connected to the front end of the balance support rod (2) via a force measuring balance (7).

2. The high-speed wind tunnel airfoil variable thickness model mechanism according to claim 1, characterized in that: The fixed portion comprises a leading edge (12), a lower base plate (6), a trailing edge (13), a wing tip plate (10) and a wing root end plate (11); the flexible skin (14), the leading edge (12), the lower base plate (6) and the trailing edge (13) are sequentially combined to form a streamlined hollow airfoil body; the wing tip plate (10) and the wing root end plate (11) correspondingly close the two end openings of the hollow airfoil body.

3. The high-speed wind tunnel airfoil variable thickness model mechanism according to claim 2, characterized in that: The crankshaft (5-8) is rotatably mounted on the lower base plate (6) via a bearing seat (5-3).

4. The high-speed wind tunnel airfoil variable thickness model mechanism according to claim 2, characterized in that: The electric cylinder (1) is mounted on the wing root end plate (11) via a support sleeve (3).

5. The high-speed wind tunnel airfoil variable thickness model mechanism according to claim 4, characterized in that: One end of the transmission shaft (4) passes through the support sleeve (3) and is connected to the piston rod of the corresponding electric cylinder (1), and the other end passes through the wing root end plate (11) and is connected to the corresponding input beam (5-1).

6. The high-speed wind tunnel airfoil variable thickness model mechanism according to claim 2, characterized in that: A sliding support (9) is provided on the lower base plate (6), and the transmission shaft (4) is in sliding cooperation with the sliding support (9).

7. The high-speed wind tunnel airfoil variable thickness model mechanism according to claim 2, characterized in that: The input beam (5-1) and the input end slider (5-4) are hinged via the input end rotating shaft (5-5).

8. The high-speed wind tunnel airfoil variable thickness model mechanism according to claim 2, characterized in that: The output beam (5-2) and the output end slider (5-6) are hinged via the output end rotating shaft (5-7).

9. The high-speed wind tunnel airfoil variable thickness model mechanism according to any one of claims 2 to 8, characterized in that: It also includes an active beam sliding module (15), which includes a vertical guide rail group and a guide slider group that are slidably matched. The vertical guide rail group is fixed to the lower base plate (6) through a guide rail support (16), and the two active beams (8) are respectively connected to the guide slider groups of the two active beam sliding modules (15).

Images