"The true method of knowledge is experiment" - William Blake

Towards the end of my junior year, my physics teacher challenged the class to work on a final project that would encompass all that we have learned over the year. We had the choice to learn something new, hone a specific discipline, or develop a method to teach the class about a specific subject. In my mind, I knew that I wanted to find a project that encompassed all three of these criteria. This is how I, along with my classmate Ian Kelley, stumbled upon building our first wind tunnel.

Going into this project, we did not know much about wind tunnels, much less how to build one. After our build, we published a guide on Instructables (available here). Within a few days, it grew on a humongous, unanticipated scale. We were able to receive feedback from individuals that were experts in the field of aerodynamics and fluid dynamics. Inspired by their support and constructive criticism, we went back to the drawing board and asked ourselves what could we do to improve our design. After a long iterative process, we were able to compile and assimilate the suggested ideas and started to build. This ible is meant more as a guide to learn from and is meant to work in tandem to the first guide. Some specific details may be left out intentionally to allow for a certain degree of independence and creativity. Experiment!.

Without a further ado, I would like to present our DIY Wind Tunnel 2.0, Project Paperclip.

Step 1: What Is a Wind Tunnel?

Although wind tunnels are not as prevalent as other high precision instruments, they have huge implications on the everyday lives of everyone and everything on Earth and beyond. From cars, airplanes, and space-faring vehicles, to buildings, bridges, and skyscrapers, knowledge and understanding gained from wind tunnel research provides a conduit for mankind's drive for innovation.

Now how does a wind tunnel work? Well the physics behind it are based off of the work of Daniel Bernoulli, a Swiss physicist. Many might remember him from the equation that you learned in physics back in high school of constant= P + 1/2 p v^2 + p g h. An equation he helped contribute to, the continuity expression in physics of A1V1=A2V2. This provides the foundation of wind tunnels by showing how if you decrease the cross sectional area, your speed subsequently increases.

Photo Credits:
#1: http://www.seriouswheels.com/pics-2005/2005-Pagani-Zonda-F-n-Wind-Tunnel-1600x1200.jpg
#2: http://airfactsjournal.com/files/2012/09/wind-tunnel.jpg
#3: http://www.efluids.com/efluids/gallery/gallery_pages/HW019/Werle_19.jpg
#4: http://www.cdn.sciencebuddies.org/Files/503/9/wind-tunnel_F.jpg
#5: https://www.grc.nasa.gov/www/k-12/airplane/Images/tuntest.jpg
#6: http://3.bp.blogspot.com/-9omxPSGsnr4/UM9nx3kN0sI/AAAAAAAAT8M/iRJpWE3bkiA/s1600/open-circuit-wind-tunnel.jpg

Nice job jamesabt007,<br><br>However I would like to know how long the Dry Ice lasts.<br><br>Regards, Stephen
What is the Reynolds number for
<p>It's for determining if the flow is straight and laminar or if it's all swirly and turbulent. Basically if the thickness of a fluid is too low compared to the flow speed the flow will become turbulent.</p>
<p>Hello!<br>Current senior in high school looking to make a closed wind tunnel for a project. How do you recommend we get started with designing the sizes and materials?</p>
<p>Thanks! Took me a couple days to finish.</p>
<p>Thank you so much for this instructable! I am making a wind tunnel of my own right now based off of yours. Just finished the test section!</p>
<p>Very good job!! This has inspired me to make one as well.<br>However, I am really new to the concept of aerodynamics and really need some guidance for my university project.<br><br>The size of the testing section needs to be 60cm x 60cm (or 24&quot; x 24&quot;). I am aiming to achieve a windspeed approximately at 10-20 m/s. So my question is what kind of fan do I need? Would I need some thing like an industrial fan such as this: http://www.bunnings.com.au/dynabreeze-60cm-blue-industrial-drum-fan_p4440780<br><br>Or should i make some thing like this so I can control the fan speed with PWM :<br>https://www.instructables.com/id/PC-Box-Fan/<br><br>So for a 120mm fan, the flow rate is usually between 50~75 CFM. I have no idea how to convert this to m/s and if I use 25 fans, would this mean I just need to add the CFM together?<br><br>I am afraid that the industrial maybe too strong and the PC fan box may not be strong enough. Please give me some guidance.<br><br>Thank you for your time and help :) </p>
<p>For anyone who has successfully built this wind tunnel: how much time did it take?</p>
<p>I guess the fans CFM is important so i was wondering if you knew what yours was so i could have a base point?</p>
<p>I am doing this project because I need to test a few of my designs...It is missing a bit of needed information like the angles of the cut parts and the lengths of parts of it</p>
<p>I am doing this project because I need to test a few of my designs...It is missing a bit of needed information like the angles of the cut parts and the lengths of parts of it</p>
<p>Cool, what speed you can get in the test section?</p>
<p>If I remember correctly, we were able to hit a range of speeds from 5m/s to 13m/s.</p>
<p>Before I worked at Instructables, I worked at the Fluid Mechanics Lab at the NASA Ames Research Center, operating huge wind tunnels all day. I'm very impressed with your project and that you were able to use so many recycled materials and get good results! Great job!</p>
<p>I gotta say, I am pretty speechless... being able to impress one of the great members I look up to on Instructables. Weirdly enough, when I mentioned that I write Instructables for my Olin Candidates weekend, one of my interviewers mentioned that she was a friend of yours. Olin is such a great school, it's definitely given you the chance to work at such cool places like Ames research facility. I hope I can visit or even work there one day too! </p>
<p>Oh cool! Who was your interviewer? It's a small school, as you know, so most people within a couple grades of each other know each other, haha.</p>
<p>Very clever and brilliant idea. Very well explained - the effort put in is clearly visible! Thanks for sharing :-) Voted!</p>
<p>Thank you so much!</p>
<p>Very well done. I like the clever use of the straws to make your honeycomb baffle. </p>
<p>Thank you for your kind words. Yet I would not dare take credit for such a great idea provided by the awesome Instructables community memebers who helped me out on my first guide. </p>
<p>Brilliant, well done.</p>
<p>Thank you!</p>
all i have to say is Woah!
<p>Mission, accomplished. :)</p>
Good work fellas
<p>Thank you!</p>
awesome project. keep learning. very well explained
<p>I sure to hope keep learning and sharing with others. Thank you!</p>
<p>Hello, I have also made a wind tunnel and tried to use smoke in it, however the smoke &quot;disintigrated&quot; because my wind speeds were too high. </p><p>What are the wind speeds in your tunnel and how did you make the smoke? </p>
<p>That's nice. Although it seems you bought some unnecessarily fancy&amp;expensive LED strips which could be replaced by a much cheaper, monochrome version, and probably an equally(if not more) expensive remote controller which could be replaced by a simple DC power supply that costs a couple bucks.</p><p>I love how you laminarized the flow by just stacking straws, when I made my mini-windtunnel, I tried gluing together a cardboard mesh for this purpose and it had awful performance.</p><p>Also, liquid nitrogen is a viable (if not better) alternative to dry ice as a means of fog generation, if you have access to it (I don't have access to dry ice, so it's actually the only option for me). A great way to make thick fog is to continuously boil water (for example, by jury-rigging an electric boiler/teapot, just don't let it boil ALL the water inside, and you'll be fine) and pass the steam through a container of liquid N₂/Dry Ice/Ordinary ice (sprinkle some salt on it for lower temperature!)/etc.</p>

About This Instructable




Bio: In my free time, I enjoy building/modifying/dismantling anything I can get my hands on. I am currently an engineering student at UCLA and ... More »
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