Shock wave boundary layer interference and elastic wallboard fluid-solid coupling experiment device

Abstract

The invention discloses a shock wave boundary layer interference and elastic wallboard fluid-solid coupling experimental device which comprises a base, a vertical plate, a top plate, an elastic wallboard mounting plate, an observation window and a shock wave adjusting part. The elastic wallboard mounting plate is provided with an elastic wallboard mounting position, the shock wave adjusting part comprises a lead screw stepping motor, a lead screw nut and a shock wave generator, the lead screw stepping motor is mounted on the top plate, the free end of a lead screw rotating shaft of the lead screw stepping motor is located below the top plate, and the lead screw nut is in threaded connection with the free end of the lead screw rotating shaft; one end of the shock wave generator is hinged to the screw nut through a hinge, and the other end is hinged to the lower surface of the top plate. The device is simple in structure, can realize the experiment of the elastic wallboard under the action of shock waves with different intensities, and is suitable for shock wave / boundary layer interference flow and elastic wallboard fluid-solid coupling experiment research.

Description

Technical Field

[0001] The invention belongs to the field of aerospace experimental technology, and in particular relates to a shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device. Background Art

[0002] Panel flutter and shock wave / boundary layer interference are two core scientific issues in the structural design and optimization of air-breathing aircraft. In the flow field, shock wave / boundary layer interference exhibits highly nonlinear characteristics, and aircraft usually adopt lightweight thin-walled structures to reduce weight and improve performance. Such structures are prone to complex aeroelastic coupling problems in the flow environment. Panel flutter is a self-excited vibration of thin-walled structures on the surface of aircraft under the coupling of inertial force, elastic force and aerodynamic force. Although its nonlinear dynamic characteristics will not immediately cause structural damage, it will accelerate the accumulation of fatigue damage, significantly reduce the service life of structural parts, and pose a potential threat to the flight safety of aircraft. In addition, the aeroelastic response and deformation of thin-walled structures will not only lead to flow separation, but may also further affect the overall performance of the aircraft. However, no special experimental device has been reported so far.

[0003] Therefore, it is necessary to design a fluid-solid coupling experimental device for inlet shock wave / boundary layer interference flow and elastic wall panels to study the aeroelasticity of the inlet wall panels and its influence on the internal flow field structure and inlet performance. Summary of the invention

[0004] In order to solve the problem of lack of experimental equipment in the study of aeroelasticity of inlet wall panels and their influence on internal flow field structure, the present invention provides a shock wave / boundary layer interference and elastic wall panel fluid-solid coupling experimental equipment.

[0005] The shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device of the present invention comprises a base, a vertical plate installed on the base, a top plate installed on the same side of the vertical plate and parallel to each other, and an elastic wall plate mounting plate installed below, an observation window installed on the vertical plate and located between the top plate and the elastic wall plate mounting plate, and a shock wave regulating part installed on the top plate; The elastic wall panel mounting plate has an elastic wall panel mounting position, which is a step hole with a circle of first step surfaces formed by first digging a groove downward in the middle of the elastic wall panel mounting plate and then digging a through hole downward at the bottom of the groove, and the first step surface is used to support and install the elastic wall panel; The shock wave adjustment part includes a screw stepper motor, a screw nut and a shock wave generator. The screw stepper motor is installed on the top plate, the free end of the screw shaft of the screw stepper motor is located below the top plate, the screw nut is threadedly connected to the free end of the screw shaft, one end of the shock wave generator is hinged to the screw nut through a hinge, and the other end is hinged to the lower surface of the top plate; the rotation of the screw shaft of the screw stepper motor drives the screw nut to move, and the movement of the screw nut drives the shock wave outlet of the shock wave generator to shift, and the displacement of the shock wave outlet changes the shock wave exit angle emitted to the elastic wall panel mounting position.

[0006] Furthermore, the observation window includes an observation window mounting port and a plexiglass plate installed in the observation window mounting port, the observation window mounting port opens at one end surface of the vertical plate, the lower inner wall of the observation window mounting port is flat, the upper inner wall is stepped with a second step surface, the bottom inner wall is stepped with a third step surface, the second step surface and the third step surface are both located on the side of the vertical plate close to the elastic wall plate mounting plate, the upper side portion of the plexiglass plate and an end portion away from the opening of the observation window mounting port are fixed on the vertical plate, the top surface of the plexiglass plate is fitted with the second step surface, the end surface of the plexiglass plate away from the opening of the observation window mounting port is fitted with the third step surface, the bottom surface of the plexiglass plate is fitted with the lower inner wall of the observation window mounting port, the plexiglass plate is located on one side of the elastic wall plate mounting plate and is flush with the side of the vertical plate on the elastic wall plate mounting plate, and the upper surface of the elastic wall plate mounting plate is higher than the bottom surface of the plexiglass plate.

[0007] Furthermore, one end of the organic glass plate located at the opening of the observation window mounting port is flush with the end of the vertical plate, and the same end of the organic glass plate, the vertical plate, the top plate and the elastic wall plate mounting plate are all provided with an inclined wedge.

[0008] Furthermore, the angle of the inclined wedge is 20°.

[0009] Furthermore, an adhesive layer for gluing the elastic wall panel is provided on the first step surface of the elastic wall panel installation position, and a protective film is attached to the adhesive layer.

[0010] Furthermore, the groove and the through hole on the elastic wall panel mounting plate are both rectangular, and the ratio of the depth to the length of the groove is 1:100-500.

[0011] Beneficial effects: The shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device of the present invention realizes a simplified structure and low cost through an active shock wave generator, and is suitable for experimental research on dynamic shock waves; the shock wave generator realizes precise angle control through a hinge and a screw stepper motor, so that the experiment can be carried out at different shock wave angles; by making the organic glass plate located on one side of the elastic wall plate mounting plate flush with the vertical plate located on one side of the elastic wall plate mounting plate, it is ensured that the inside of the experimental section is parallel and no step structure appears, thereby reducing the influence of the three-dimensional effect on the elastic wall plate; by making the upper surface of the elastic wall plate mounting plate higher than the bottom surface of the organic glass plate, the lateral displacement of the organic glass plate is limited; by arranging an inclined wedge at the same end of the organic glass plate, the vertical plate, the top plate and the elastic wall plate mounting plate, the vibration and the interference of the detached shock wave on the flow field can be effectively reduced; By designing a 20° wedge angle, the device can maintain structural stability under different experimental conditions and ensure the reliability of experimental data; by arranging an adhesive layer for gluing the elastic wall panel on the first step surface of the elastic wall panel mounting position, and a protective film is attached to the adhesive layer, the aerodynamic elasticity of the inlet duct wall panel under a complex support state and its influence on the internal flow field structure and the inlet duct performance can be studied; by making the grooves and through holes on the elastic wall panel mounting plate rectangular, the depth and length ratio of the grooves is 1:100-500, and by changing the depth and length ratio of the grooves, the vibration characteristics under different dynamic pressure conditions can be studied; this experimental device is suitable for elastic wall panels of different materials (such as elastic wall panels made of stainless steel, aluminum alloy, titanium alloy, and C-SiC composite materials), meets different experimental needs, and increases the applicability and flexibility of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the experimental device of the present invention; Figure 2 It is a right side view of the experimental device of the present invention; Figure 3 It is a front view of the experimental device of the present invention; Figure 4 for Figure 3 Schematic diagram of NN cross section; Figure 5 It is a structural schematic diagram of the elastic wall plate mounting plate of the experimental device of the present invention; Figure 6 It is a structural schematic diagram of the shock wave adjustment part of the experimental device of the present invention; Figure 7 It is a schematic diagram of the structure of the experimental device of the present invention after the shock wave generator is displaced; In the figure: 1. base; 2. vertical plate; 3. elastic wall panel mounting plate; 4. top plate; 5. observation window; 6. screw stepper motor; 7. elastic wall panel mounting position; 8. shock wave generator; 9. hinge; 10. screw nut. DETAILED DESCRIPTION

[0013] The present invention will now be further described in detail by way of embodiments in conjunction with the accompanying drawings, but the present invention is not limited to the embodiments.

[0014] Example 1

[0015] like Figure 1-4 As shown, the present invention is a shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device, including a base 1 evenly distributed with a plurality of through holes extending upward and downward, a vertical plate 2 installed on the base 1, a top plate 4 installed on the same side of the vertical plate 2 and both horizontal, and an elastic wall plate mounting plate 3 below, an observation window 5 installed on the vertical plate 2 and located between the top plate 4 and the elastic wall plate mounting plate 3, and a shock wave regulating part installed on the top plate 4.

[0016] The vertical plate 2 is mounted on the base 1 by bolts. Specifically, the base 1 is provided with a plurality of mounting holes that penetrate vertically, and the bottom surface of the vertical plate 2 is provided with corresponding screw holes. The bolts are passed through the mounting holes of the base 1 and screwed into the screw holes of the vertical plate 2 for fastening. The use of bolts for fastening is a conventional technical means. Similarly, a plurality of mounting holes that penetrate vertically are provided at one end of the top plate 4, and corresponding screw holes are provided on the top surface of the vertical plate 2. The top plate 4 and the vertical plate 2 are fastened by bolts that penetrate the mounting holes of the top plate 4 and screwed into the screw holes on the top surface of the vertical plate 2; a plurality of screw holes are provided on one end surface of the elastic wall plate mounting plate 3, and corresponding mounting holes that penetrate horizontally are provided on the vertical plate 2. The elastic wall plate mounting plate 3 and the vertical plate 2 are fastened by bolts that penetrate the horizontal mounting holes of the vertical plate 2 and screwed into the screw holes of the elastic wall plate mounting plate 3.

[0017] like Figure 5 As shown, the elastic wall panel mounting plate 3 has an elastic wall panel mounting position 7, and the elastic wall panel mounting position 7 is formed by first digging a groove downward in the middle of the elastic wall panel mounting plate 3, and then digging a through hole downward at the bottom of the groove to form a step hole with a circle of first step surfaces, and the first step surface is used to support the installation of the elastic wall panel; the above-mentioned groove and through hole are both rectangular (the length and width of the through hole are respectively smaller than the length and width of the groove), and the depth and length ratio of the groove is 1:100-500.

[0018] The above-mentioned shock wave adjustment part includes a screw stepper motor 6, a screw nut 10 and a shock wave generator 8. The screw stepper motor 6 is installed on the upper surface of the top plate 4. The screw shaft of the screw stepper motor 6 passes through the top plate 4 from top to bottom. The free end of the screw shaft of the screw stepper motor 6 (that is, the front section of the screw shaft) is located below the top plate 4. The screw nut 10 is threadedly connected to the free end of the screw shaft. One end of the shock wave generator 8 is hinged to the screw nut 10 through a hinge 9, and the other end is also hinged to the lower surface of the top plate 4 through a hinge 9 (that is, the shock wave generator 8 is suspended on two hinges 9). The installation of the hinge 9 can refer to the prior art. The rotation of the screw shaft of the screw stepper motor 6 drives the screw nut 10 to move up and down. The up and down movement of the screw nut 10 drives the shock wave outlet of the shock wave generator 8 to shift up and down. The up and down displacement of the shock wave outlet changes the shock wave emission angle emitted to the elastic wall panel mounting position 7 (such as Figure 6 , Figure 7 The length of the free end of the screw shaft must be sufficient to adjust the shock wave exit angle.

[0019] The above-mentioned observation window 5 includes an observation window mounting opening and a rectangular organic glass plate installed in the observation window mounting opening. The observation window mounting opening is open at one end face of the vertical plate 2 and is horizontally U-shaped. The lower inner wall of the observation window mounting opening is flat, the upper inner wall is stepped with a second step surface, and the bottom inner wall is stepped with a third step surface. The second step surface and the third step surface are both located on the side of the vertical plate 2 close to the elastic wall plate mounting plate 3. The upper side part and the end part away from the mounting opening are pre-embedded with a plurality of bolts extending out of one side of the organic glass plate. Corresponding mounting holes are provided on the vertical plate 2. The bolts are passed through the mounting holes of the vertical plate 2 and fastened with nuts to fix the organic glass plate on the vertical plate 2. At the same time, the top surface of the organic glass plate is fitted with the second step surface, the end surface of the organic glass plate away from the observation window mounting opening is fitted with the third step surface, the bottom surface of the organic glass plate is fitted with the lower inner wall of the observation window mounting opening, and the side of the organic glass plate located on the elastic wall plate mounting plate 3 is flush with the side of the vertical plate 2 located on the elastic wall plate mounting plate 3. After the elastic wall panel mounting plate 3 is installed, its upper surface is slightly higher than the bottom surface of the organic glass plate. The end of the organic glass plate located at the opening of the observation window mounting port is flush with the end of the vertical plate 2. The same end of the organic glass plate, the vertical plate 2, the top plate 4 and the elastic wall panel mounting plate 3 is provided with an inclined wedge with an angle of 20°. The organic glass plate can be installed by inserting it from the opening end of the observation window mounting port.

[0020] Example 2

[0021] In Example 1, a glue layer for gluing the elastic wall panel is provided on the first step surface of the elastic wall panel installation position 7, and a protective film is attached to the glue layer; the thickness of the glue layer is 0.1-1 mm. Other than this, it is the same as Example 1.

[0022] The working principle of the present invention is as follows: first tear off the protective film on the glue layer of the elastic wall panel installation position 7 and glue the elastic wall panel, then the incoming flow passes through the shock wave generator 8 to generate an oblique shock wave that is shot into the upper surface of the experimental elastic wall panel, and the angle of the shock wave generator 8 is controlled by the screw stepper motor 6 to realize the response of the experimental elastic wall panel under different incident shock wave angles. The upper and lower walls of the elastic wall panel vibrate and deform under the action of the pressure difference. Under the action of the instantaneous pressure difference, the elastic wall panel vibrates, causing the wall panel curvature to change. The changing wall panel curvature affects the breathing motion of the separation bubble under the shock wave / boundary layer interference. At the same time, a laser can be injected from the observation window 5, and the instantaneous structure of the flow field above the experimental elastic wall panel can be observed using the schlieren measurement system, laying a foundation for the study of shock wave / boundary layer interference characteristics and the aeroelastic study of the elastic wall panel under fluid-solid coupling.

[0023] The various parts of the experimental device of the present invention are connected by threads, which is convenient for disassembly, and the parts in each component are simply matched and can be reused; the shock wave angle of the experimental device of the present invention can be quickly changed, and at the same time, experimental research on various wall panel materials can be realized by replacing the experimental elastic wall panel, providing a reference for the research on shock wave / boundary layer interference characteristics and the wall panel fluid-solid coupling experimental research.

[0024] The above-mentioned technologies not specifically mentioned are all referred to the prior art.

[0025] Based on the above-mentioned ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above-mentioned description. The technical scope of the present invention is not limited to the contents of the specification.

Claims

1. A shock wave / boundary layer interference and elastic wall fluid-solid coupling experimental device, characterized in that: The invention comprises a base (1), a vertical plate (2) mounted on the base (1), a top plate (4) mounted on the same side of the vertical plate (2) and parallel to each other, and a lower elastic wall plate mounting plate (3), an observation window (5) mounted on the vertical plate (2) and located between the top plate (4) and the elastic wall plate mounting plate (3), and a shock wave adjustment portion mounted on the top plate (4); The elastic wall panel mounting plate (3) has an elastic wall panel mounting position (7), wherein the elastic wall panel mounting position (7) is a step hole having a circle of first step surfaces formed by first digging a groove downwards in the middle of the elastic wall panel mounting plate (3) and then digging a through hole downwards at the bottom of the groove, wherein the first step surface is used to support and install the elastic wall panel; The shock wave adjustment unit comprises a screw stepper motor (6), a screw nut (10) and a shock wave generator (8); the screw stepper motor (6) is mounted on the top plate (4); the free end of the screw shaft of the screw stepper motor (6) is located below the top plate (4); the screw nut (10) is threadedly connected to the free end of the screw shaft; one end of the shock wave generator (8) is hinged to the screw nut (10) via a hinge (9); and the other end is hinged to the lower surface of the top plate (4); the screw shaft of the screw stepper motor (6) rotates to drive the screw nut (10) to move; the movement of the screw nut (10) drives the shock wave outlet of the shock wave generator (8) to shift; the shift of the shock wave outlet changes the shock wave exit angle emitted to the elastic wall plate mounting position (7).

2. The shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device according to claim 1 is characterized in that: The observation window (5) comprises an observation window mounting opening and a plexiglass plate mounted on the observation window mounting opening, the observation window mounting opening is opened at one end surface of the vertical plate (2), the lower inner wall of the observation window mounting opening is flat, the upper inner wall is stepped with a second step surface, the bottom inner wall is stepped with a third step surface, the second step surface and the third step surface are both located on a side of the vertical plate (2) close to the elastic wall plate mounting plate (3), the upper side portion of the plexiglass plate and an end portion away from the opening of the observation window mounting opening are fixed on the vertical plate (2), the top surface of the plexiglass plate is bonded to the second step surface, the end surface of the plexiglass plate away from the opening of the observation window mounting opening is bonded to the third step surface, the bottom surface of the plexiglass plate is bonded to the lower inner wall of the observation window mounting opening, the side surface of the plexiglass plate located on the elastic wall plate mounting plate (3) is flush with the side surface of the vertical plate (2) located on the elastic wall plate mounting plate (3), and the upper surface of the elastic wall plate mounting plate (3) is higher than the bottom surface of the plexiglass plate.

3. The shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device according to claim 2 is characterized in that: One end of the organic glass plate located at the opening of the observation window mounting port is flush with the end of the vertical plate (2), and the same end of the organic glass plate, the vertical plate (2), the top plate (4) and the elastic wall plate mounting plate (3) are all provided with an inclined wedge.

4. The shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device according to claim 3 is characterized in that: The angle of the wedge is 20°.

5. The shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device according to claim 4 is characterized in that: An adhesive layer for gluing the elastic wall panel is provided on the first step surface of the elastic wall panel installation position (7), and a protective film is attached to the adhesive layer.

6. The shock wave / boundary layer interference and elastic wall plate fluid-solid coupling experimental device according to claim 5 is characterized in that: The groove and the through hole on the elastic wall plate mounting plate (3) are both rectangular, and the ratio of the depth to the length of the groove is 1:100-500.

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