Desktop Windtunnel
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- čas přidán 26. 10. 2020
- I am not sure why I made this. Just a bit of fun during lockdown and to satisfy my natural curiosity!
It's an opportunity to try to photograph some cool images of airflow in different situations. I am not expecting to make any new discoveries!
I have already found that the slo-mo feature on my smart phone takes interesting shots of the smoke but the best pictures are stills taken with 1/4 or 1/2 second exposures. In these pictures the smoke trails are smoothed into lines which are clearer to see. - Věda a technologie
Wow that's really cool! Now I kind of want to make one even though I don't really have a use for one.
Yes, that's exactly how I came to make it! It just needed to be made, (even though I don't i have a use for it!).
Superb. The e-cigi makes it so safe and easy. The entry design is so elegant, so retro. Excellent video.
I’ve been wanting to build one for year but no one has shown such a simple and elegant solution to making one. I plan on changing a few things like the way to generate smoke and have the ability to move the smoke left to right for items that may not be even all the way across like car bodies over headlights vs dead center of the vehicle. But thank you for this. This is something anyone should be able to do and tweak to their own likings or specs thanks to just showing your design 👏🏻
the flow is turbulent even before striking the test object🤔
The error consist in pushing the smoke inside, that's causing turbulence. The right way to do it is keeping the smoke in a neutral pressure reservoir and let the venturi effect suck the smoke in.
@@electronicscaosThe wind tunnel should also be reversed, meaning installing the fan on the venturi side rather than the narrow end
e-cigarette for smoke Brilliant. Looking to do this in my High School. Thanks
Hi Mark, that's a great build! Simple, but sufficient and a damn ingenious idea to actually make use of those vapes - I'm sometimes tempted to call the firefighters when extreme vapers open their car doors. However I have one hint perhaps to make it better, you might use a (planar) Laser (Example Bosch DIY PLT 2) it has a halfround lens in the laser path of the beam and I have already used it to watch mesmerising flow of mist in the evening over lawn for example and air being uplifted by heat convection. Those laser planes can actually visualise a cut through air and you can just tilt the plane to investigate not only in one 2D-plane but also in the z-direction. The lasers used in this Bosch PLT2 are actually quite powerful.
neatly done Mark ,many thanks for sharing
What needless fun. Happy to have stumbled by. Scaled down (quite a bit) more, I almost see a mass novelty item waiting to happen.
What a great idea. Perhaps incorporating a pencil sharpener!
I like the phrase 'needless fun' it sums up all my projects on my channel, 'Markwaller99'!
This is bloody brilliant
That is awesome. The vape as the smoke maker is very clever
I wish I was smart enough to build one for a guy I met in Alberta who’s building one big enough that he’s looking at my tool truck as housing for the generator. Super smart stuff. Thanks for the vid.
Love this, what a great build. I make model/high power rockets and I'm going to build one to look at different nosecone profiles.
That is impressive. Neat work there
The fan should be on the venturi side of the tunnel pullint air out. And subsequently the test object rotated accordingly; this ensures the flow does not come into the tunnel already turbulent.
ecig is genius! Well done.
This is really cool!
This is very cool!
Amazing job.
thank you for your video, i now know what's missing in my wind tunnel : the straws
That's so cool!
Great build. Super!
Would be nice to have no test object to see true laminar flow. Love the slow motion shots.
So Cool !!
That’s badass.
Very cool project.
E-Cig is a great idea!
We get it, you vape
Hello, thanks for the video. What type of compressor are you using, and where to get a similar one? Many thanks.
This is lovely! I'd love for my students to do this project; are there any resources you can recommend that might help them with the construction.
I seriously considered building one like this just for fun, but I don't really have anything I need it for so I didn't. I couldn't think of a good way to make smoke though. Honestly I have no idea how regular wind tunnels do it. The only one I've used wasn't set up for that.Using an e-cig is so simple yet brilliant.
The only snag with e-cigs is the smell. I didn't want to fill my workshop with nicotine so I chose a sweet fruit vape flavour - and now my workshop smalls of mangoes! I also tried one of those ultra sound mist generators - but it did not produce enough mist.
My current curiosity is to wonder if I could upend then whole thing into the vertical - and film a falling sycamore seed!
@@ttstam Good idea. It would not smell of Mangoes!
@@MarkWaller Instead of only using propylene glycol, you could use a mix of propylene glycol and vegetable glycerin. More vegetable glycerin can produce more fog but can also make the liquid thicker.
@@bass2762 Thanks, good idea!
Insane...
Very nice
Fantastic
I love it, what inspired you to make it
what type of foam is used in the venturi?
Hi mark, is there a way we connect to get a more detailed understanding of the windtunnel
Than u sir
What flavour smoke is that anyway?
cool!
I’m going to make one similar. One question, how would you make the smoke trails smooth and laminar?
This is great! I would like to recreate it to test golf discs. Which mean the chamber would have to be larger to accommodate the size of the disc.
Maybe you can suggest a way to spin the disc while it's in the chamber.
I am imagining some sort of spindle with levers to change the angle of the disc (like a helicopter)
Also, I am thinking of how to measure the air velocity???
I would measure windspeed by videoing the smoke and measuring how far it travels over one (or ten) frames. It is not necessary to spin the disc, because the only function of the spin is to make the aerofoil stable in the air. The air flow will be the same whether the disc spins or not. You could motorise the disc on a thin spindle but it would be tricky to do and would serve little purpose! However, as fun as this project was, do not expect too much. There will always be some eddies in the airflow.
Mark, any chance you have a parts list for this? It really is a fantastic project!
There is no parts list as such because I put it together from things I mostly had already, however I bought some of the bits from ebay as follows...
The Aquarium air pump I used was one of these…
www.ebay.co.uk/itm/USB-Mini-Air-Pump-Water-Pump-Oxygen-Aerator-Aquarium-Fish-Tank-Portable-Home-UK/402419542163?hash=item5db212e893:g:O6cAAOSwixNfVyQN
The e cigarette was…
www.ebay.co.uk/itm/e-cig-cigarette-ce4-eGo-T-shisha-1100mAh-battery-vape-pen-charger-atomiser-kit/253790449905?hash=item3b1716f0f1:g:EAwAAOSweVNbYcYB
The fan was a brushless 12V one like this…
www.ebay.co.uk/itm/DC-12V-120mm-x32mm-Blower-Cooling-Fan-Centrifugal-Turbo-Brushless-Fans-Cooler/232977792053?hash=item363e8efc35:g:cloAAOSwXMxbz9pA
The motor controller was this one…
www.ebay.co.uk/itm/Mini-DC-Motor-Speed-Control-Driver-Board-3V-35V-5A-PWM-Controller-LED-dimmer/163091515028?hash=item25f9030694:g:GLUAAOSwXudbHZdk
Everything else was made from stuff I had lying around in my shed. By the way, I decided in the end that the wall of straws introduced more turbulence than it removed, so I cut it out! Also, the best laminar flow was generated with the windspeed quite low, which I achieved by partially blocking the fan vent.
If I did it again I would put more distance between the fan and the main chamber, because some of the turbulance I was getting was coming from the fan.
Good luck with your project
@@MarkWaller HI Mark, Would you like to sell this wind tunnel to me? Please let me know. Thanks
sorry to ask another question, but how did you glue the straws in place (if you glued them at all)
thank you
I cut paper straws to lengths of about 2 cms each and just glued them into position. After the first two rows of straws it gets quite sticky, and unstable so it is best to let it dry before starting the next two rows. Having said that I took out the straws in the end as they inroduced small eddies of their own. It is proved best to just let the air flow in a laminar fashion without the wall of straws.
How do the tubes straighten the flow and make the flow laminar? I mean once the flow passes the tubes there should create vortices and eddies because every tube has the biggest velocity vector at centre or am i getting something wrong? But actually in the real facilities turbulance grids are used. The straws seem to act more as turbulance grid.
You are right. The idea was to stop any large eddies but of course the straws create small eddies of their own. You can see this in the video. In a way it is a turbulance grid creating turbulence on a small scale which decays quickly and resolves to laminar flow. The eddies are on a very small scale and do not show up in long exposure photos. In the end I removed the straws and it did not seem to be much different! The larger tubes at the other end do work to stop the fan causing a spiral flow in the chamber
I recently made a larger version wind tunnel and found that using straws as a wind modifier simply slows down the venturi flow. So I took them off and now the flow, although more "raggedy" and not as laminar, actually provides an environment that is more faithful to an actual outdoors scenario, complete with eddys, turbulence and wind bouncing around. If the item one is testing will be used out in the real world, I think utilizing real world conditions is a better bet. After all, there won't be any straws up in the clouds to make your flight more "laminar".
Yes. I agree. I went through exactly the same thoughts and took the straws out. I think it is better now! Great minds...etc!
hi, love the video. but i was wondering how you made the smoke injector, specifically the part with the 4 tubes. i have been trying to figure it out as im doing the same project.
thanks!
same with the venturi
I used 3mm brass tubes. One tube from below splits into four or five venturi outlets. To reduce the turbulence around the tubes, I sandwiched them in a balsa cowling with an aerofoil streamlined shape. If the air flow speed and the smoke flow speed are matched the the turbulence is minimised. I hope this helps.
@@MarkWaller thank you so much for the help!
How much it cost to do
hello i would like to recreate this for my physics skilled work, how did you do it with the aquarium pump and the e cigarette?
I bought a cheap (blue) air pump and a cheap e-cigaarette. The cig was mounted inside a piece of (white) plastic piping so the air flow goes in the right direction. You can see both in in the picture. The button on the cig is accessible through the side of the white pipe. The white pipe comes apart to allow the cig to be refilled and charged.
@@MarkWaller okay thanks! :D
Excusme sir, can you tell / explain part for making smoke for detailed? I have project to build homemade windtunnel. Thankyou sir
The smoke comes froma cheap e-cigarette with a small aquarium air pump to drive the air flow. The pump will only blow, (not suck) so I had to enclose and seal the e-cigarette in a piece of plastic piping to blow the air through it in the right direction. The e-cigarette smoke is activated by a push button on its side so I arranged a small mechanism in the side of the pipe so the button can be pressed to activate the smoke while inside its sealed tube chamber. I hope this helps you.
Can you buy one already built.@@MarkWaller
Your project is very cool! Did you use a computer fan to pull the air out?
Hi, why are you using a brushless fan? Thanks
Any fan would do but brushless motors are more powerful and I found this one online for a sensible price.
@@MarkWaller but my doubt is that i dont know what fan i have to buy, because i do need a suction fan, and normal fans expel the air isnt it? Could you help me plss
@@nicov7274 brushless is motor type. It could be brushed or brushless.
Only difference is power and cost
@@nicov7274 so long as the fan is at the exit end of the tube and turning the right way it will draw air through the tunnel. If your fan blow, turn it around, the other side must be sucking!!
Where can I get this wind tunnel?
This was a home built project and not for salke. You can easily copy my design and it is not too expensive. (Leave out the drinking straws, they don't work very well!)
This was a home built project and not for salke. You can easily copy my design and it is not too expensive. (Leave out the drinking straws, they don't work very well!)
Hey Mark! I am a student trying to build a small wind tunnel for a school project. I am pretty inspired by your design! Could we get into contact maybe by email or something so I can ask you some questions on how you built this? Thanks
Slots & slats @ 2:00!
Excuse me, sirI have a project. I finished everything except the cigarettes. Don't press too hard. What should I do? 0:23
How to get the straws there?
your hands
Hi Mark -- we just reached out via LinkedIn to see if we can get your permission to use some stills from your video in our upcoming issue. Hopefully that's a monitored channel for you. If not, perhaps there is another way of facilitating that permission? Thanks!
I have found you on LinkedIn and replied there. In short, "Yes, glad to help!".
use laminar flow air.....
Is it possible retrieve data of some kind using this model
Just add sensors accordingly
Can we get a tutorial?? I would like to build something similar.
Excuse me mister.
Because i make the same project, can you tell me what electronic cigarette you use and how you connected with the air pump ??? Because i have stuck and i don't find a good electronic cigarette 😂😂😂
I used the cheapest e-cigarette I could find and the least offensive flavour (Mangoes!) Since the pump would only blow (not suck) I had to enclose the e-cigarette in a piece of plastic pipe and push the air through the e-cigarette, (right to left in the picture.) I devised a press button on the side of the tube such that if pressed it transferred the pressure onto the ON button of the e-cigarette underneath.... to make smoke. (You have to hold it on)
I have another question, smoke injectors where can i find them?
@@user-gl5dw5rv8u I used some 3mm tubing I already had. You can buy metal pipes at any good model shop, usually in aluminium or brass. To reduce the eddies it is best if the smoke joins the airflow at about the same speed as the airflow it is joining. I made the injectors quite long so as to reduce the eddies caused by the injector tube mounting - which was itself made from steamlined balsa wood. Having experimented, I came to the conclusion that the wall of drinking straws introduced small eddies and so I removed it for a smoother airflow. Good luck.
Try straws for getting a laminar flow!
Try watching the video! (and then read the comments)
Can we buy this from you?
No! 🙂
Thought it was great… then out came the flaps and slats lol 😂
hahahhahaa
The authors have two wrong scientific approaches: researching the creation of Lift force and Low pressure at upper side of the wing, relative to the ground surface and Earth. I explain the aerodynamic cavitation and existence of Lee side aerocavern, and creation of Aerodynamic force.
Super..from mamse college