I wish there was a way for HNers to share Kickstarter campaigns that they are excited about. This is one I never heard about, but may have considered for my car/Hot Wheel enthusiast son.
I know we can obviously just post the link, but seems like that would be considered a promotion (possibly against guidelines) more than just sharing something that HN might enjoy/discuss.
I’m not a huge KS backer (mostly have backed the occasional board game), but I’m sure there’s some pretty cool niche tech that would at least be interesting to hear about, and hear others discuss.
dpifke 56 days ago [-]
Write a blog post about why you think it's cool, and post that to HN.
duxup 56 days ago [-]
I've seen wind tunnels in use in videos and TV shows.
Question:
Let's say I had this device and I had a small vehicle and I put it in there to make changes to. Would this tunnel help me actually create a tiny car that legitimately is faster in some measurable way outside the wind tunnel?
I know there's a lot of unknowns in my scenario, but I'm thinking about the utility / outcome of using this device, just in general beyond the cool factor. Is a tiny wind tunnel actually likely to produce real life results for someone?
Edit: Thanks for all the answers everyone, informative info.
seabass-labrax 56 days ago [-]
I don't think it would make any difference for, say, an RC car that could fit inside the tunnel. At the speeds where aerodynamics would make a measurable difference to drag, other aspects such as traction and downforce would be considerably more important. I don't see how it would be plausible to measure downforce with this miniature wind tunnel, because there's no strain gauge to be seen.
For aircraft of any size this would have more utility. This is because, even at low speeds, aircraft must be balanced (center of mass and center of pressure very close to each other) and ideally won't stall at a low AoA (Angle of Attack).
In any case, it would only be practical if you used this with scaled-down models (as used to be the case with real aerodynamics), and it is more expensive and less accurate than doing a computer fluid dynamics simulation. With the simulation, you can do it at full scale in every situation imaginable with high realism and accuracy.
marcosdumay 56 days ago [-]
In principle, yes, a wind tunnel would help you create a car that is either faster or more efficient, or to improve the ground effect, or let you control it better. It does that by letting you check the places where the airflow becomes chaotic, that can't be simulated very well.
On practice I doubt you are trying to optimize a tiny car. And the chaotic flow is very dependent of scale. So the only parts that transfer from a tiny car into a normal one are the ones that are easy to simulate.
hackingonempty 56 days ago [-]
You can but you are almost certainly going to get better results using a computational fluid dynamics (CFD) feature of your CAD software. This simulates the wind and shows you exactly where and how much pressure is building up. You can iterate on your design without producing a new physical model though it is very compute intensive.
FreeCAD has a plugin to do it and there are videos on YouTube of people showing you how to use it.
which is 5 times denser than air and has a higher Reynolds number. Oddly SF6 is safe to breathe (as an inert filler gas such as Nitrogen, Argon or Helium) but is also one of the most powerful known GHGs.
satiric 56 days ago [-]
Wind tunnels for scale size cars are much less useful than they were just 15 years ago. My university sold its wind tunnel for 1/10th scale cars, it was just not that useful compared to CFD. CFD can get you simulations that take into account rotating tires (a big deal on the open wheel cars we were working on). You also don't have to worry about inaccuracies from 3D printing (or however you make the model).
echoangle 56 days ago [-]
You need to make sure your measurements are actually representative of the flow regime you will actually have. You need to look at Reynolds number and mach number. If you use the actual model and don't use a small scale model, you just need to use the same flow speed as you will use in the application later. Then you could theoretically measure drag force and look at vortices to check where to modify the shape.
56 days ago [-]
56 days ago [-]
rob74 56 days ago [-]
I fully concur with the top comment on the article page:
> This is super cool. [...] However, I'd like to slap the Youtuber that decided to record in portrait rather than landscape - especially as this device is rather obviously horizontal rather than vertical.
dylan604 56 days ago [-]
Sadly, this will only get worse. Younger people that spend so much time on TikTok will just feel comfortable with that aspect ratio. I know kids that spend more time in portrait mode on their devices than they do in front of the wide screen TV at home; mainly because their parents are planted in front of it watching what they want. Sucking in those TikTok videos is a bit of their independence which is only emboldening the preference.
At least it didn't have that lame voice with transcription text on it
Liquix 56 days ago [-]
the baked-in animated captions are so jarring and make things impossible to watch. i think your observations are astute though -- the constant bright shapes popping up every .5s is required to hold the tiktok generation's attention long enough to digest a narrative
I predict in 2 years there will be some aspect-ratio fill-in using genai. The thought of which terrifies me but I can definitely see it happening.
1024core 56 days ago [-]
We really need to bring the Internet Punch Protocol into reality, to deliver the occasional punch to such morons.
JStanton617 56 days ago [-]
Definitely justifying this by helping my nephew with his Pinewood Derby car next year
khaki54 56 days ago [-]
I was thinking the same thing, fully knowing pinewood derby is mostly concerned with friction and center of gravity.
excalibur 56 days ago [-]
Is there any practical reason to put a footlong sub in a wind tunnel? No. Do I need to see someone do it? Yes!
ortusdux 56 days ago [-]
This looks like a fun 3d printing project. I've been looking for an excuse to pick up a mini fog machine for photography.
fsloth 56 days ago [-]
I did not know mini fog machines were a thing until now - and now I want one! Do you have any references? I think apart from the see-through portion and some fan the windtunnel would be quite 3d-printable.
The professional grade units in Norman's video are $150 and $250, but there are plenty of listings around the $50 mark.
They are basically just vapes with a small fan. IIRC, the special smoke fluid is just the vegetable glycerin base typically used in vape products.
notpublic 56 days ago [-]
search for "Ultrasonic Mist Maker"...
56 days ago [-]
moose44 56 days ago [-]
Looks super cool! But I feel I would grow annoyed with the noise.
criddell 56 days ago [-]
It looks like something that would be a lot of fun for a day or two and then end up in my attic where I would forget about it.
This is the kind of thing I should probably buy used on eBay and then resell it a week later.
dylan604 56 days ago [-]
You mean like the model train set that my dad spent weeks setting up on an 8'x4' sheet of plywood with the fake grass, buildings, cars, and people that eventually was spent playing with in total of about 4 hours? Yeah, that one is in a box in the equivalent of my attic as well for the past 25 years now
BobaFloutist 56 days ago [-]
The thing that's important to remember is that for your dad, the weeks of setup was also play.
mey 56 days ago [-]
I wish Lego's were available as a rental. I miss playing with Lego but have ZERO desire for them to occupy space in my house. If I could I could redbox/netflix a set, that'd be amazing.
dylan604 56 days ago [-]
Buy a 3D printer. Print your own blocks. Get tired of the blocks. Eliminate blocks. 3D print your next bit of enterainment
fxtentacle 56 days ago [-]
You clearly never tried this. The tolerances for Lego bricks to work well are too tight for what 3D printers can handle.
dylan604 56 days ago [-]
Then scale it to make the tolerances work /s
tartoran 56 days ago [-]
Or go to Legoland or something. If you have a kid even better.
criddell 56 days ago [-]
LEGOs are available as a rental.
mey 54 days ago [-]
For some reason I hadn't looked into it, looking at a few services now, thanks for pushing my in this direction.
omegabravo 56 days ago [-]
building it is the most valuable part
dylan604 56 days ago [-]
I did the same with model airplanes and cars. I had the planes hanging from the ceiling in my bedroom. Once built, I might have played with them for a minute by flying them around the room before hanging them. Some had lights that could be turned on for an interesting effect at bed time.
thenewwazoo 56 days ago [-]
I can't figure out where the fog goes.
iwontberude 56 days ago [-]
Recirculates and then dissipates into the air around it when you are done
dylan604 56 days ago [-]
Back to the front?
56 days ago [-]
Rendered at 20:04:56 GMT+0000 (Coordinated Universal Time) with Vercel.
I wish there was a way for HNers to share Kickstarter campaigns that they are excited about. This is one I never heard about, but may have considered for my car/Hot Wheel enthusiast son.
I know we can obviously just post the link, but seems like that would be considered a promotion (possibly against guidelines) more than just sharing something that HN might enjoy/discuss.
I’m not a huge KS backer (mostly have backed the occasional board game), but I’m sure there’s some pretty cool niche tech that would at least be interesting to hear about, and hear others discuss.
Question:
Let's say I had this device and I had a small vehicle and I put it in there to make changes to. Would this tunnel help me actually create a tiny car that legitimately is faster in some measurable way outside the wind tunnel?
I know there's a lot of unknowns in my scenario, but I'm thinking about the utility / outcome of using this device, just in general beyond the cool factor. Is a tiny wind tunnel actually likely to produce real life results for someone?
Edit: Thanks for all the answers everyone, informative info.
For aircraft of any size this would have more utility. This is because, even at low speeds, aircraft must be balanced (center of mass and center of pressure very close to each other) and ideally won't stall at a low AoA (Angle of Attack).
In any case, it would only be practical if you used this with scaled-down models (as used to be the case with real aerodynamics), and it is more expensive and less accurate than doing a computer fluid dynamics simulation. With the simulation, you can do it at full scale in every situation imaginable with high realism and accuracy.
On practice I doubt you are trying to optimize a tiny car. And the chaotic flow is very dependent of scale. So the only parts that transfer from a tiny car into a normal one are the ones that are easy to simulate.
FreeCAD has a plugin to do it and there are videos on YouTube of people showing you how to use it.
https://en.wikipedia.org/wiki/Reynolds_number
if you adjust things so that the Reynolds number is the same for the model and the real thing.
Somebody in the next building over had a "wind tunnel" that used this stuff
https://en.wikipedia.org/wiki/Sulfur_hexafluoride
which is 5 times denser than air and has a higher Reynolds number. Oddly SF6 is safe to breathe (as an inert filler gas such as Nitrogen, Argon or Helium) but is also one of the most powerful known GHGs.
> This is super cool. [...] However, I'd like to slap the Youtuber that decided to record in portrait rather than landscape - especially as this device is rather obviously horizontal rather than vertical.
At least it didn't have that lame voice with transcription text on it
https://www.youtube.com/watch?v=f2picMQC-9E
The professional grade units in Norman's video are $150 and $250, but there are plenty of listings around the $50 mark.
They are basically just vapes with a small fan. IIRC, the special smoke fluid is just the vegetable glycerin base typically used in vape products.
This is the kind of thing I should probably buy used on eBay and then resell it a week later.