Modularized 3D printing low-speed demonstration wind tunnel

Abstract

The invention relates to a modular 3D printing low-speed demonstration wind tunnel, and belongs to the field of wind tunnel technologies and education equipment. In order to solve the problems that an existing wind tunnel is high in cost, fixed in structure and difficult to popularize, full-modular design is adopted, an air inlet channel section, a honeycomb rectification section, a screen steady flow section, a contraction acceleration section, a test section, a diffusion section and other core assemblies are manufactured through the 3D printing technology, all the modules are rapidly assembled through standardized connecting pieces, and flexible configuration and upgrading are supported. The cross section of the wind tunnel test section is 102 mm * 102 mm, the overall length is 1.1-1.6 m and adjustable, the maximum wind speed is 4-15 m / s, and PLA or PETG materials are used for printing. The device has the advantages of being low in cost, easy to manufacture, high in safety and excellent in airflow quality, and is suitable for STEM education, scientific demonstration and experiment teaching.

Description

Technical Field

[0001] This invention relates to the field of wind tunnel technology, specifically a low-speed wind tunnel for STEM education, scientific demonstrations and experiments, and in particular a demonstration wind tunnel that adopts a modular design and is manufactured using 3D printing technology. This wind tunnel is characterized by its simple structure, low cost, ease of manufacturing and assembly, and is suitable for aerodynamic visualization demonstrations in homes, schools, museums and other settings. Background Technology

[0002] As an important aerodynamic experimental device, wind tunnels are widely used in scientific research and teaching in aerospace, automotive engineering and other fields. Traditional wind tunnels are usually made of metal or composite materials, which are complex in structure, expensive, and require professional sites and operating skills, making them difficult to popularize in educational or public demonstration scenarios. In recent years, with the rise of DIY culture, some simple wind tunnel solutions designed by amateur enthusiasts have emerged. However, these solutions often have problems such as poor cost control, high manufacturing complexity, and inconsistent manufacturing quality, which limit their widespread application.

[0003] In addition, existing low-speed wind tunnels are insufficient in terms of modularity and customizability. Most designs adopt an integral structure, which makes it difficult to flexibly adjust or upgrade according to specific needs, such as changing the size of the test section to adapt to different flow rate requirements. At the same time, traditional manufacturing methods such as CNC machining or manual production are costly and dependent on specialized equipment, which is not conducive to large-scale promotion.

[0004] In recent years, the rapid development of 3D printing technology has made low-cost, rapid prototyping possible. In particular, the widespread adoption of medium-sized FDM 3D printers has made it feasible to manufacture large structural components. However, there is currently no mature design that combines 3D printing with modular wind tunnels to achieve a "print-to-use" solution. This invention aims to solve the above problems by providing a highly modular, easy-to-3D-print low-speed demonstration wind tunnel that can be produced using ordinary home 3D printers and supports flexible configuration and upgrades.

[0005] Based on the shortcomings of the prior art, this invention achieves lightweight, low-cost, and highly operable wind tunnels through modular design and 3D printing optimization. Summary of the Invention

[0006] Technical problems to be solved The main objective of this invention is to address the limitations of existing low-speed wind tunnels in terms of cost, modularity, and ease of manufacture. Specifically, it includes: 1. reducing the manufacturing cost and complexity of wind tunnels to make them suitable for non-professional environments such as homes and schools; 2. providing a highly modular design that allows users to flexibly assemble, disassemble, and upgrade components according to their needs; 3. optimizing the wind tunnel structure to facilitate production using ordinary 3D printers while ensuring airflow quality and demonstration effects; and 4. enhancing the safety and ease of operation of wind tunnels to make them suitable for children and beginners.

[0007] Technical solution The present invention discloses a modular 3D-printed low-speed demonstration wind tunnel, the core of which is to adopt a modular architecture, decompose the wind tunnel into multiple independent functional modules, each of which is manufactured by 3D printing and assembled by standardized connectors. The overall structure includes an air intake section, a honeycomb rectification section, a screen flow stabilization section, a contraction acceleration section, a test section, a diffusion section, and a power system, etc. The modules are connected by clamps or magnetic connections to ensure airtightness and ease of assembly.

[0008] 1. The wind tunnel has an overall length of 1.1 meters, and the test section has a cross-section of 102 millimeters. The wind tunnel is 102 mm thick and can reach a maximum airflow velocity of 4.0 m / s. All structural components are manufactured using common 3D printing materials such as PLA or PETG, with a total material consumption of approximately 5-6 kg. The wind tunnel design is compatible with various 3D printer bed sizes; the basic version requires a print bed of at least 256 mm. It is 256 mm thick, but through modular design, it can be adapted to fit sizes as small as 180 mm. Its 180mm print bed makes it suitable for entry-level home 3D printers.

[0009] Key modules include: 1. Intake section: As the airflow inlet, it adopts a tapered design to reduce flow loss.

[0010] 2. Honeycomb rectifier section: The built-in honeycomb structure is used to straighten the airflow and reduce turbulence.

[0011] 3. Screen flow stabilization section: Equipped with multiple layers of screens to further stabilize the airflow.

[0012] 4. Contraction Acceleration Section: The airflow is accelerated to the test section by the contraction of the cross section.

[0013] 5. Test section: Transparent or open design to facilitate placement of test models and visualization.

[0014] 6. Diffusion section: the airflow outlet section.

[0015] 7. Power system: Driven by a standard 140 mm PC fan, with support for speed control.

[0016] Furthermore, the wind tunnel supports various module expansions, such as a smoke laser flow visualization system (including a smoke injection uniform release device and a laser illumination device), as well as force balance and velocity measurement modules. Safety is a primary concern, with features such as protective shields and low-voltage operation to ensure safe use by children.

[0017] Beneficial effects The present invention has the following advantages over the prior art: 1) Low cost and high operability: Manufacturing is carried out through 3D printing, which has low material costs and does not require professional equipment. Ordinary users can complete the manufacturing and assembly.

[0018] 2) Highly modular: The modular design allows users to select or upgrade specific components as needed, such as replacing test sections or adding other modules, which improves flexibility and scalability.

[0019] 3) Excellent aerodynamic performance: Through honeycomb rectification and screen flow stabilization design, the uniformity of airflow and low turbulence in the test section are ensured, meeting the demonstration requirements.

[0020] 4) Safety and ease of use: The low wind speed design and protective measures make it suitable for children to operate and support STEM education and science popularization activities.

[0021] 5) Environmental adaptability: The compact size and lightweight design facilitate transportation and storage, making it suitable for a variety of occasions.

[0022] The specific implementation method is described in detail below with reference to the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a modular 3D printing low-speed demonstration wind tunnel according to the present invention.

[0024] Figure 2 This is a 3D model of the air intake section.

[0025] Figure 3 This is a 3D model diagram of the cellular rectifier section.

[0026] Figure 4 This is a 3D model diagram of the stabilizing section of the screen.

[0027] Figure 5 This is a schematic diagram of a variant of the screen flow stabilization section with a smoke injection port.

[0028] Figure 6 This is a 3D model diagram of the contraction acceleration segment.

[0029] Figure 7 This is a 3D model of the test section.

[0030] Figure 8 This is a 3D model diagram of the diffusion section.

[0031] Figure 9 This is a 3D model diagram of the extended diffusion section.

[0032] Figure 10 This is a 3D model of the protective shield.

[0033] Figure 11 This is a 3D model of the large connecting clamp.

[0034] Figure 12 This is a 3D model of a small connecting clamp.

[0035] Figure 13 It is a 3D model of a high support frame.

[0036] Figure 14 It is a 3D model of a low support frame.

[0037] The following will be combined with the appendix Figures 1 to 14 The specific implementation methods are described in detail. Detailed Implementation

[0038] The invention will now be described in further detail with reference to the accompanying drawings. This embodiment uses a basic wind tunnel as an example, with an overall length of 1.1 meters and a test section size of 102 millimeters. 102 mm, maximum wind speed 4.0 m / s. Users can adjust the settings according to their needs by referring to the upgrade options.

[0039] Overall Structure Overview like Figure 1 As shown, the modular 3D-printed low-speed demonstration wind tunnel of the present invention consists of multiple modules connected in series, including an air inlet section 1, a honeycomb rectifying section 2, a screen flow stabilizing section 3, a screen flow stabilizing section 4 (equipped with a smoke injection and uniform release device), a contraction acceleration section 5, a test section 6, a diffusion section 7, a power system 8 (fan unit), an extended diffusion section 9, and a protective cover 10. Except for the power system 8, which is connected to the diffusion section 7 and the extended diffusion section 9 using standard screws, all other modules have flanges at their connecting edges and are connected by clamps (such as...). Figure 11 and Figure 12 The large connecting clamp 11 and the small connecting clamp 12 shown ensure airtightness and rigidity. The wind tunnel adopts a lightweight design, with a total weight of approximately 10 kg, and can be supported by a high support frame 13 or a low support frame 14. Figure 13 and Figure 14 It provides support and adapts to different presentation heights.

[0040] The wind tunnel operates as follows: airflow is drawn in through inlet section 1, rectified by honeycomb rectifier section 2 and screen stabilization sections 3 and 4, accelerated in contraction acceleration section 5, enters test section 6 for model testing, and finally exits through diffuser sections 7 and 9. The power system 8 uses a standard 140mm PC fan, driven by an external power supply, supporting PWM speed control for wind speed regulation. All modules are manufactured using 3D printing; PETG or PLA are recommended printing materials due to their high strength, ease of printing, and environmental friendliness. Recommended printing parameters: layer height 0.2mm, infill rate 20%, to ensure structural strength and aerodynamic smoothness.

[0041] Detailed description of the air intake section Intake section 1 is the wind tunnel's entrance module, and its design directly affects airflow intake efficiency. For example... Figure 2 As shown, this section adopts a tapering design with a relatively large inlet cross-section (e.g., 150 mm). 150 mm), the exit section matches the subsequent module (102 mm). (102 mm). This design reduces inlet loss and prevents airflow separation. The module wall thickness is set to 3 mm, and the internal surfaces need to be polished or coated during 3D printing to reduce frictional resistance.

[0042] Intake section 1 has high manufacturing compatibility and can be manufactured in 256 mm diameter sections. It prints entirely on a 256mm print bed. For smaller printers, this section can be divided into two parts, assembled by pins and adhesive; the segmented design reduces the minimum print bed requirement to 180mm. 180 mm. In practical applications, a filter screen can be added to this section to prevent foreign objects from entering.

[0043] Detailed description of the cellular rectifier section The honeycomb rectifying section 2 is used to eliminate large-scale turbulence in the airflow and ensure consistent airflow direction. For example... Figure 3 As shown, this section integrates a honeycomb structure, with each honeycomb consisting of multiple hexagonal units, each unit measuring 10 millimeters. 10 mm in diameter and 50 mm in depth. The honeycomb structure is 3D printed in one piece using PLA material to balance strength and weight.

[0044] The modular design of the cellular rectifier section 2 allows users to easily replace cells of different sizes to adapt to varying flow rate requirements. In terms of manufacturing, support material is used during the printing of the cellular structure, and is later manually removed to ensure internal unobstructed flow.

[0045] Detailed description of the screen flow stabilization section The screen-controlled flow stabilization sections 3 and 4 further stabilize the airflow and reduce small-scale turbulence. For example... Figure 4As shown, this section contains multiple layers of screens (usually 2-3 layers), with a mesh size of 40-60 mesh, made of nylon or metal mesh, and is placed at the junction between the modules of the honeycomb rectifier section 2 and the screen flow stabilizer sections 3 and 4, and is fixed with large connecting clamps.

[0046] To improve the demonstration effect, this invention also provides a variant with uniform smoke injection and release function. For example... Figure 5 As shown, the screen flow stabilization section 4 can integrate a smoke injection and uniform release device, which is connected to a smoke generator. The smoke generator uses a mixture of vegetable glycerin and propylene glycol, which is heated by a battery to produce smoke for flow visualization.

[0047] Detailed explanation of the contraction acceleration segment The contraction acceleration section 5 is a crucial part of the wind tunnel, responsible for accelerating the airflow to the test section 6. For example... Figure 6 As shown, this section adopts a curved tapering design, with the inlet cross-section matching the screen flow stabilization section (102 mm). 102 mm), the exit section is slightly smaller than the test section (e.g., 95 mm). (95 mm), with a contraction ratio of 1.1:1. This design, based on Bernoulli's principle, efficiently accelerates airflow while preventing flow separation.

[0048] For the 3D printing of the shrinkage acceleration section 4, attention should be paid to the smoothness of the internal surface. It is recommended to use ABS material and polish it with acetone to reduce friction loss. The module is approximately 200 mm long and can be adapted to a small print bed through its segmented design.

[0049] Detailed description of the test section Test section 6 is the core demonstration area of ​​the wind tunnel, used to place test models (such as aircraft airfoils, car models, etc.). Figure 7 As shown, this section uses a transparent acrylic or open frame design for easy observation and photography. The cross-sectional dimension is 102 mm. 102 mm in diameter and 300 mm in length, with a slot on top for model support or sensor mounting.

[0050] The modular design of Test Section 6 allows users to replace test sections with different sizes, such as larger cross-sections for group demonstrations. Models can be secured in various ways, including magnetic attachment and clamping, and are compatible with LEGO or standard scale models. To enhance visualization, LED panels or laser sheet light sources can be installed around the test section, working in conjunction with a smoke system to display a streamer spectrum.

[0051] Detailed description of the diffusion section Diffusion section 7 and extended diffusion section 9 are used to slow down the airflow, restore pressure, and reduce energy loss. For example... Figure 8 and 9 As shown, the diffuser section and the extended diffuser section adopt a gradually expanding design, with the inlet cross-section matching the test section and the outlet cross-section enlarged to 150 mm. 150 mm diameter, with a diffusion angle of 5 degrees to prevent flow separation. Diffusion section 7 and extended diffusion section 9 are directly connected to the power system 8 (fan unit). The fan is a 140 mm PC fan, driven by an external 12V power supply, supporting PWM speed control to achieve adjustable airflow from 0-4 m / s. A protective cover 10 is added to the outside of the fan. Figure 10 ( ), prevent contact, and ensure safety.

[0052] Connection and support system The connection between modules uses large connecting clamp 11 and small connecting clamp 12. Figure 11 and Figure 12 The clamps are 3D printed and secured with screws. The support system includes a high support frame 13 and a low support frame 14. Figure 13 and Figure 14 The height is adjustable, making it suitable for desktop or standing operation.

[0053] Manufacturing and assembly process The manufacturing and assembly process of a wind tunnel is as follows: 1) 3D Printing Modules: Use an FDM 3D printer to print each module sequentially. Recommended printing parameters: Diameter 0.4 mm, layer height 0.2 mm, printing temperature 230°C for PETG and 200°C for PLA. After printing, remove the supports and perform surface treatment (such as sanding).

[0054] 2) Assemble the modules: Connect the modules in sequence and secure them with clamps. Apply silicone sealant to the joints to ensure airtightness.

[0055] 3) Install the power system: Connect the fan unit to the diffuser section, and turn on the power supply and speed controller.

[0056] After assembly, testing is conducted: the fan is turned on, the fan speed is adjusted, and smoke visualization is used to check the uniformity of airflow. Typical applications include measuring model drag and observing vortex generation.

Claims

1. A modular 3D printing low-speed demonstration wind tunnel, characterized in that: It includes an inlet section, a honeycomb rectifying section, a screen flow stabilizing section, a contraction acceleration section, a test section, and a diffusion section. Each section is manufactured independently through modular design and assembled into a complete wind tunnel using standardized connectors or clamps. All sections are manufactured using 3D printing technology and PLA or PETG materials. The overall length of the wind tunnel is 1.1 meters, the test section has a cross-section of 102 mm × 102 mm, and the maximum airflow velocity is 4.0 m / s.

2. The modular 3D printing low-speed demonstration wind tunnel according to claim 1, characterized in that: The air intake section adopts a tapered design, with the inlet cross-section larger than the outlet cross-section; the honeycomb rectifier section integrates a honeycomb structure, with each honeycomb unit measuring 10 mm × 10 mm; the screen flow stabilization section contains multiple layers of screens; the contraction acceleration section has a curved contraction profile with a contraction ratio of 1.1:1; the test section is transparent or open, facilitating model placement and visualization; the diffusion section has a gradually expanding design with a diffusion angle of 5 degrees.

3. The modular 3D printing low-speed demonstration wind tunnel according to claim 1, characterized in that: The sections are connected by clamps.

4. The modular 3D printing low-speed demonstration wind tunnel according to claim 1, characterized in that: It also includes a power system, which is a 140 mm PC fan driven by an external power supply and supports PWM speed control.

5. The modular 3D printing low-speed demonstration wind tunnel according to claim 1, characterized in that: The wind tunnel is designed with a protective cover and support frame to ensure operational safety; it supports module upgrades, including the addition of a smoke laser flow display system, sensors, or force balance systems for educational demonstrations and experimental measurements.

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