A replaceable airfoil laminar flow wind tunnel teaching experiment device

Abstract

The utility model relates to the field of experimental device structure discloses a kind of replaceable airfoil laminar flow wind tunnel teaching experimental device, including shell, support rod and wing, the upper end and lower end of the shell are detachably connected with corresponding cover plate;Two the cover plate are provided with several mounting holes, the both ends of the support rod are detachably connected in corresponding mounting hole;The wing is slidably connected on the support rod.The utility model has beneficial effect, the wing is installed or disassembled from the one end of support rod, to meet the wing of different size and shape in experimental device experiment, also by setting several mounting holes on cover plate, to facilitate the both ends of support rod are connected in mounting hole not on the same vertical line, and then adjust the inclination angle (i.

Description

Technical Field

[0001] This utility model relates to the technical field of experimental device structure, specifically to a teaching experimental device for a replaceable airfoil laminar flow wind tunnel. Background Technology

[0002] Students will understand the basic principles of fluid mechanics (such as Bernoulli's law, boundary layer, lift / drag generation mechanisms, etc.). Compared with research-grade wind tunnels, it has a simpler structure, is easier to operate, and emphasizes safety and observability. It is widely used in engineering majors in universities (such as aerospace, mechanical, and mechanics) and in popular science experiments in secondary schools.

[0003] Currently, the wings of the wind tunnel teaching experimental device are fixedly connected inside the device, and the tilt angle of the wings cannot be adjusted. This makes it impossible to experiment with wings of different shapes (models) and different tilt angles (angles of attack), and the teaching experimental device can only meet a limited number of experiments. Utility Model Content

[0004] The technical problem this invention aims to solve is that the existing wind tunnel teaching experimental devices have fixed wings and non-adjustable angle of attack, resulting in a limited number of teaching experiments that can be performed. The purpose is to provide a laminar flow wind tunnel teaching experimental device with interchangeable airfoils, which adjusts the tilt angle (i.e., angle of attack) of the wings by adjusting the installation angle of the support rod, thereby improving the versatility of the experimental equipment and meeting the teaching experiments with different needs.

[0005] This utility model is achieved through the following technical solution: A teaching experimental device for a replaceable airfoil laminar flow wind tunnel includes a shell, a support rod, and an airfoil. The upper and lower ends of the shell are detachably connected to corresponding cover plates. Each of the two cover plates is provided with several mounting holes. The two ends of the support rod are detachably connected to the corresponding mounting holes. The airfoil is slidably connected to the support rod.

[0006] The beneficial effects of this utility model are that by providing detachable cover plates at both the upper and lower ends of the shell, and providing several mounting holes on the cover plates, the wing is slidably connected to the support rod. This allows the wing to be installed or removed from one end of the support rod when it needs to be replaced, so as to meet the experimental needs of wings of different sizes and shapes in the experimental device. Furthermore, by providing several mounting holes on the cover plates, it is possible to connect the two ends of the support rod to mounting holes that are not on the same vertical line, thereby adjusting the tilt angle (i.e., angle of attack) of the wing, thereby increasing the versatility of the experimental equipment and meeting the needs of teaching experiments with different requirements.

[0007] In some embodiments, the mounting holes are evenly distributed along the length of the corresponding cover plate, and the mounting holes on one cover plate are vertically aligned with the corresponding mounting holes on another cover plate. By evenly distributing the mounting holes along the length of the corresponding cover plates, the installation position of the support rod can be adjusted, thereby adjusting the distance between the wing and the wind source. Furthermore, by aligning the mounting holes on one cover plate with the corresponding mounting holes on another cover plate, the support rod can be vertically installed inside the housing to enable experiments on the vertical vertical movement of the wing.

[0008] In some embodiments, the mounting hole is an elliptical hole, the major axis of which is parallel to the long side of the cover plate. Setting the mounting hole as an elliptical hole facilitates the removal of the support rod from the cover plate and allows for tilted installation of the support rod.

[0009] In some embodiments, a transparent observation plate is also included, which is disposed on one side of the housing. By providing a transparent observation plate, the airflow path can be observed intuitively, making the flow field distribution clear at a glance.

[0010] In some embodiments, the system further includes a fan, a mounting housing, and a smoke delivery pipe. The mounting housing is connected to one end of the housing, the fan is connected to the inside of one end of the mounting housing, and the outlet end of the smoke delivery pipe extends into the inside of the mounting housing and is located at the air outlet end of the fan. By providing a smoke delivery pipe, the smoke moves with the airflow, allowing for a more direct and visual observation of the airflow path.

[0011] In some embodiments, a rectifier is also included, one end of which is connected to the mounting housing and the other end is located inside the housing. By setting the rectifier, turbulent and non-uniform airflow is transformed into stable, uniform, and regular flow, providing the required flow field conditions for the experimental process.

[0012] In some embodiments, the inner side of the rectifier is provided with several rectifying grids, and several rectifying holes are provided within the rectifying grids, which are arranged along the length direction of the housing. By providing rectifying holes, uniform resistance is formed to the airflow. Regions with high flow velocity are slowed down due to resistance, while regions with low flow velocity are accelerated under pressure. Ultimately, the flow velocity downstream of the rectifier is more uniformly distributed across the cross-section, meeting the requirements of experiments (such as airfoil aerodynamic characteristic testing) for a uniform flow field.

[0013] In some embodiments, a diffuser duct is further included, comprising a conical section and a horizontal section. The larger end of the conical section is connected to the housing, and the smaller end is connected to the horizontal section. The horizontal section is connected to the mounting housing, and the rectifier is located inside the horizontal section. By setting the horizontal section, the airflow first passes through the rectifier to uniformly distribute the flow field, and then passes through the conical section to achieve a linear attenuation of the airflow velocity (achieving a dynamic pressure-to-static pressure conversion efficiency of 92% based on Bernoulli's equation). The optimized diffuser angle improves the static pressure recovery coefficient while avoiding flow separation.

[0014] In some embodiments, the ratio of the maximum cross-sectional dimension to the minimum cross-sectional dimension of the tapered portion is 14:1. This 14:1 gradually expanding cross-section achieves a linear decrease in airflow velocity (achieving a dynamic-to-static pressure conversion efficiency of 92% based on Bernoulli's equation).

[0015] In some embodiments, the support rod includes at least one, the support rod has a circular cross-section, and the wing is provided with at least one connecting hole, the connecting hole engaging with the pivot hole of the support rod. By providing the support rod, when the air is still, the wing, under the influence of gravity, will slide onto the bottom plate of the air duct. When the fan is started, according to Bernoulli's principle, the pressure on the lower surface of the wing is greater than the pressure on the upper surface, and the wing will generate lift. When the lift is greater than the weight of the wing, the wing will rise. The stronger the wind, the greater the lift. Eventually, the wing rises to its highest point and is blocked by the cover plate at the top of the air duct.

[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects: 1. The wings can be installed or removed from one end of the support rod to accommodate wings of different sizes and shapes in the experimental setup. Several mounting holes are also provided on the cover plate to allow the two ends of the support rod to be connected to mounting holes that are not on the same vertical line, thereby adjusting the tilt angle (i.e., angle of attack) of the wings. This increases the versatility of the experimental equipment and meets the needs of teaching experiments with different requirements.

[0017] 2. By setting up a transparent observation panel, the airflow path can be observed intuitively, making the flow field distribution clear at a glance.

[0018] 3. By setting up a smoke delivery pipe, the smoke moves with the airflow, allowing for a more direct and intuitive observation of the airflow path.

[0019] 4. A linear decrease in airflow velocity is achieved through a gradually expanding cross section of 14:1 (achieving a dynamic pressure-to-static pressure conversion efficiency of 92% based on Bernoulli's equation). Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a structural diagram of the present utility model; Figure 2 This is an exploded view of the present invention; Figure 3 This is a structural diagram of the wing when it is installed at an angle in this utility model; Figure 4 This is a structural diagram of the wing when it is vertically installed in this utility model.

[0021] The attached diagram shows the markings and corresponding component names: 10 housing, 11 cover plate, 111 mounting hole, 12 transparent observation plate, 13 diffusion duct, 20 rectifier, 21 partition plate, 30 equipment compartment, 31 smoke conveying pipe, 32 mounting shell, 33 fan, 34 baffle, 40 support base, 50 wing, 51 support rod. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0023] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] In the description of this utility model, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.

[0025] The terms "first," "second," etc., used in this utility model are merely for clarity of description and are not intended to limit any order or emphasize importance. Furthermore, the term "connection" as used herein, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0026] Example like Figures 1-4 As shown, this embodiment provides a replaceable airfoil laminar flow wind tunnel teaching experimental device, including a shell 10, a support rod 51, and an airfoil 50. The upper and lower ends of the shell 10 are detachably connected to corresponding cover plates 11. Each cover plate 11 has several mounting holes 111, and both ends of the support rod 51 are detachably connected to the corresponding mounting holes 111. The airfoil 50 is slidably connected to the support rod 51. This allows for the installation or removal of the airfoil 50 from one end of the support rod 51 when it needs to be replaced, accommodating airfoils of different sizes and shapes for experimentation within the experimental device. Furthermore, the mounting holes 111 on the cover plates 11 allow the two ends of the support rod 51 to be connected to mounting holes 111 that are not on the same vertical line, thereby adjusting the tilt angle (i.e., angle of attack) of the airfoil 50, increasing the versatility of the experimental equipment and meeting the needs of different teaching experiments.

[0027] See Figures 1-4 The mounting holes 111 are evenly distributed along the length of the corresponding cover plate 11, and the mounting holes 111 on one cover plate 11 are vertically aligned with the corresponding mounting holes 111 on the other cover plate 11. By evenly distributing the mounting holes 111 along the length of the corresponding cover plate 11, the installation position of the support rod 51 can be adjusted, thereby adjusting the distance between the wing 50 and the wind source. Furthermore, by aligning the mounting holes 111 on one cover plate 11 with the corresponding mounting holes 111 on the other cover plate 11, the support rod 51 can be vertically installed inside the housing 10, enabling experiments on the vertical up-and-down movement of the wing 50.

[0028] See Figures 1-4 The mounting hole 111 is an elliptical hole, and the major axis of the elliptical hole is parallel to the long side of the cover plate 11. By setting the mounting hole 111 as an elliptical hole, it is convenient to pull the support rod 51 out of the cover plate 11 and to facilitate the inclined installation of the support rod 51.

[0029] See Figure 1 and Figure 2 It also includes a transparent observation plate 12, which is disposed on one side of the housing 10. By providing the transparent observation plate 12, the airflow path can be observed intuitively, making the flow field distribution clear at a glance.

[0030] See Figure 1 and Figure 2 It also includes a fan 33, a mounting housing 32, and a smoke delivery pipe 31. The mounting housing 32 is connected to one end of the housing 10, the fan 33 is connected to the inner side of one end of the mounting housing 32, and the outlet end of the smoke delivery pipe 31 extends into the inner side of the mounting housing 32 and is located at the air outlet end of the fan 33. By setting up the smoke delivery pipe 31, the smoke moves with the airflow, allowing for a more intuitive observation of the airflow path.

[0031] See Figure 1 and Figure 2 It also includes a rectifier 20, one end of which is connected to the mounting housing 32, and the other end is located inside the housing 10. By setting the rectifier 20, the turbulent and non-uniform airflow is transformed into a stable, uniform, and regular flow, providing the required flow field conditions for the experimental process.

[0032] See Figure 1 and Figure 2 The rectifier 20 has several rectifier grids on its inner side, and several rectifier holes are arranged within the rectifier grids along the length of the housing 10. By setting the rectifier holes, a uniform resistance is formed to the airflow. Areas with high flow velocity are slowed down by the resistance, while areas with low flow velocity are accelerated by the pressure. Ultimately, the flow velocity downstream of the rectifier 20 is more uniformly distributed across the cross-section, meeting the requirements of experiments (such as airfoil aerodynamic characteristic testing) for a uniform flow field. The rectifier grid is composed of several perpendicularly intersecting baffles 21. The thickness of the baffles 21 is 0.8 mm, which can reduce the turbulence coefficient to below 0.15, achieving more than 85% laminarization of the airflow, effectively eliminating eddies and ensuring that the uniformity of the outlet airflow is within ±5%.

[0033] See Figure 1 and Figure 4 It also includes a diffuser duct 13, which comprises a conical section and a horizontal section. The larger end of the conical section is connected to the housing 10, and the smaller end is connected to the horizontal section. The horizontal section is connected to the mounting housing 32, and the rectifier 20 is located inside the horizontal section. By setting the horizontal section, the airflow first passes through the rectifier 20 to create a uniform flow field, and then passes through the conical section to achieve a linear attenuation of the airflow velocity (achieving a dynamic pressure-to-static pressure conversion efficiency of 92% based on Bernoulli's equation). The optimized diffuser angle improves the static pressure recovery coefficient while avoiding flow separation.

[0034] See Figure 1 and Figure 4 The ratio of the maximum to the minimum cross-sectional dimension of the conical section is 14:1. This 14:1 gradually expanding cross-section achieves a linear decrease in airflow velocity (achieving a dynamic-to-static pressure conversion efficiency of 92% based on Bernoulli's equation).

[0035] See Figure 3 and Figure 4 The support rod 51 includes at least one component, and the cross-section of the support rod 51 is circular. The wing 50 is provided with at least one connecting hole, which mates with the axle hole of the support rod 51. By providing the support rod 51, when the air is still, the wing 50 will slide onto the bottom plate of the air duct under the action of gravity. When the fan 33 is started, according to Bernoulli's principle, the pressure on the lower surface of the wing 50 is greater than the pressure on the upper surface, and the wing 50 will generate lift. When the lift is greater than the weight of the wing 50, the wing 50 will rise. The stronger the wind, the greater the lift. Finally, the wing 50 rises to its highest point and is blocked by the cover plate 11 at the upper end of the air duct. See Figures 1-3 The present invention also includes an equipment compartment 30, which is connected to the outer end of the mounting shell 32. The smoke generator, the power supply for the fan 33, etc., are all installed inside the equipment compartment 30. A smoke switch, a power switch, and a fan 33 speed control knob are installed on the outer shell of the equipment compartment 30 to turn the fan 33 and the smoke generator on and off.

[0036] See Figure 2 It also includes a baffle 34, which is connected to the end of the mounting housing 32 away from the rectifier 20 and located at the end of the fan 33 away from the air outlet.

[0037] See Figures 1-4 It also includes a support base 40, which is connected to the lower end of the housing 10 away from the fan 33, so that the housing 10 can be installed horizontally. The fan in this utility model is a server-grade brushless motor for heat dissipation, with a high power output of 32W (12V / 2.7A). It adopts fourth-generation PWM pulse width modulation technology to achieve stepless fan speed adjustment from 20% to 100%, and while maintaining a maximum air volume of 45CFM, it controls the operating noise to below 25dB, achieving industrial-grade quiet standards.

[0038] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A replaceable airfoil laminar wind tunnel teaching experiment device, characterized in that, include: The housing has corresponding cover plates detachably connected to both its upper and lower ends; The support rod has several mounting holes on both cover plates, and both ends of the support rod are detachably connected to the corresponding mounting holes. The wing is slidably connected to the support rod.

2. The interchangeable airfoil laminar flow wind tunnel teaching experiment device according to claim 1, characterized in that, The mounting holes are evenly distributed along the length of the corresponding cover plate, and the mounting holes on one cover plate are vertically aligned with the corresponding mounting holes on the other cover plate.

3. The interchangeable airfoil laminar flow wind tunnel teaching experiment device according to claim 2, characterized in that, The mounting hole is an elliptical hole, and the major axis of the elliptical hole is parallel to the long side of the cover plate.

4. The replaceable airfoil laminar flow wind tunnel teaching experimental device according to claim 1, characterized in that, It also includes a transparent observation panel, which is disposed on one side of the housing.

5. The interchangeable airfoil laminar flow wind tunnel teaching experiment device according to claim 1, characterized in that, It also includes a fan, a mounting housing, and a smoke delivery pipe. The mounting housing is connected to one end of the housing, the fan is connected to the inside of one end of the mounting housing, and the outlet end of the smoke delivery pipe extends into the inside of the mounting housing and is located at the air outlet end of the fan.

6. The interchangeable airfoil laminar flow wind tunnel teaching experiment device according to claim 5, characterized in that, It also includes a rectifier, one end of which is connected to the mounting housing and the other end is located inside the housing.

7. The interchangeable airfoil laminar flow wind tunnel teaching experiment device according to claim 6, characterized in that, The rectifier has several rectifier grids on its inner side, and several rectifier holes are provided in the rectifier grids. The rectifier holes are arranged along the length direction of the housing.

8. The interchangeable airfoil laminar flow wind tunnel teaching experiment device according to claim 6, characterized in that, It also includes a diffusion duct, which includes a conical section and a horizontal section. The large end of the conical section is connected to the housing, and the small end is connected to the horizontal section. The horizontal section is connected to the mounting housing, and the rectifier is located inside the horizontal section.

9. The interchangeable airfoil laminar flow wind tunnel teaching experiment device according to claim 8, characterized in that, The ratio of the maximum cross-sectional dimension to the minimum cross-sectional dimension of the tapered portion is 14:

1.

10. The interchangeable airfoil laminar flow wind tunnel teaching experiment device according to any one of claims 1-9, characterized in that, The support rod includes at least one, the cross-section of the support rod is circular, and at least one connecting hole is provided on the wing, the connecting hole cooperating with the phase hole of the support rod.

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