Building a Homemade Wind Tunnel for High School Project | Aerodynamics DIY

[arriluk97]

Hi guys!

I am doing a project for my High School, here in Spain, that is obligatory for everyone. As a love everything related with planes and aerodynamics I've decided to create this wind tunnel. Is approximately 2,15 meters long and it weights around 10 kilos. It is made 100% of wood and it creates a wind speed of 115 km/h when the body is completely close. It isn't finished yet but it is almost. I show to you this project to ask you a question. As you know, to get reliable results, you should have a regular wind flow and in the first part of the tunnel, you need to have something to create this wind flow. I was thinking of sticking straws but I need 6000 of them and that is too much, what else do you recommend to get the regular wind flow? Thank you for your help!

PS: You can tell me what do you think about this project! :)

 

[berkeman]

Welcome to the PF.

Very nice work! You might look at different kinds of packaging materials, to try to find something that has many parallel compartments. I've seen packaging for cardboard box contents that has a number of cardboard panels that interlock to form individual compartments. You could even make something similar yourself, with rectangular flat cardboard or plastic pieces with slots cut 1/2 way across them at regular intervals. Then hook them together at the slots to form an x-y array of channels.

I'll try to find a picture of what I mean a bit later today...

 

[berkeman]

If you do a Google Images search on Honeycomb Cardboard, you will get some good hits to explore. Some pics:

Honeycomb Cardboard 1 http://harhurlreastless.blog.com/2014/05/11/honeycomb-cardboard/

Honeycomb Intersecting Rectangular Boards http://timberhunt.com/product/technology16.html

You can try other similar Google Images searches to find other potential diffuser structures for your wind tunnel. Have fun!

 

[marcusl]

That's a nice project! I have seen homemade wind tunnels that use a clever flow straightening structure that you can make yourself very easily and inexpensively. I'll try to describe it. Take a large, flat, thin, paper card--approximately the thickness of cardboard that breakfast cereal boxes are made of, for example. Fold it back and forth to produce a "fan-fold". Now place this between two flat cards, with a few dabs of glue to hold it together. It will look something like this:

__________________________
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

Forgive the rendering--imagine no gaps. Dimensions of one to a few cm should be fine.
Now put another fanfold on top, and another flat card, and so on until you fill your space.

__________________________
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

The length (into and out of the paper) should be long enough to straighten the flow but not so long that the pressure drop becomes large.

You should probably insert this between the front cone and the test space.

 

[arriluk97]

Thank you for all your support and your ideas! I will think about it because this kind of honeycombs are a better idea than the straws! Although I will need a lot of cardboard!

 

[berkeman]

Thank you for all your support and your ideas! I will think about it because this kind of honeycombs are a better idea than the straws! Although I will need a lot of cardboard!

If you look around at packaging stores, you may be able to find the material already made for not much money...

 

[arriluk97]

If you look around at packaging stores, you may be able to find the material already made for not much money...

I have been looking at it but the main problem is that the honeycomb is not as wide as I need. For example if I use straws I need one 6 times larger than its diameter, and the honeycomb is quite short. I will look for it again!

 

[arriluk97]

So guys, I write in this post again, after a while, just to announce that I have finished my wind tunnel and now is completely operative! I leave you a link if you want to check it! Thank you for all support during the project!

 

[berkeman]

Very nice work! So you did end up going with the straws then for the diffuser? :-)

 

[arriluk97]

Very nice work! So you did end up going with the straws then for the diffuser? :)

Yes! I thought it would be easier using straws! Because the honeycomb was to short... Now I am planning to keep on working and design my own cars!