5 ms·
How about firing air at an object through a series of nozzles, measure the resulting turbulence and then solve for shape ;-)
by rsp1984 9y ago
How about firing air at an object through a series of nozzles, measure the resulting turbulence and then solve for shape ;-)
- JadeNB 9y ago> measure the resulting turbulence Just a quick solution of a million-dollar math problem (https://en.wikipedia.org/wiki/Millennium_Prize_Problems#Navier.E2.80.93Stokes_existence_and_smoothness https://en.wikipedia.org/wiki/Millennium_Prize_Problems#Navi...) and you're on your way!
- eru 9y agoYou don't have to solve the Navier Stokes equations analytical for this. You don't even have to solve them explicitly at all: I can see a grad student just getting a lot of experimental data and throwing it all at a neural net with good results.
- vacri 9y agoIt doesn't solve the hidden cavity problem very well, though.
- eru 9y agoIndeed. At least not in a way I can think of within thirty seconds.
- JadeNB 9y ago> You don't have to solve the Navier Stokes equations analytical for this. Yes, to be sure you are right. It was just a silly (and, as you point out, mathematically inaccurate) joke.
- AndrewKemendo 9y agoI think that's already a thing, right? They use that for corneal deformation at a minimum.
- bcmertz 9y agoI feel like this would only work in limited cases of laminar flow and even then the scattering of the air would be complicated af I think
- eru 9y agoIf you can solve the math (even just numerically), you can in principle do it for non-laminar flow.
- david_b 9y agoA somewhat similar, much simpler process is in wide use in the manufacturing industry for form measurement: https://www.google.de/search?q=air+gaging https://www.google.de/search?q=air+gaging
- radarsat1 9y agoSeems like the turbulence would present difficulties. How about lasers? Oh wait that's a known method.. :) How about shining a normal light though and just inverting the shadow calculations.. hmm.. has that been done?
- doctoboggan 9y agoI think I might have done what you are talking about a while ago. See my write up on my website: http://jack.minardi.org/software/whats-in-a-shadow/ http://jack.minardi.org/software/whats-in-a-shadow/
- PhasmaFelis 9y agoFascinating. I'd wondered a while back how feasible it is to reconstruct an object from a 3-view orthographic projection, e.g. https://s-media-cache-ak0.pinimg.com/originals/b2/92/a9/b292a911cd0a60b3c345851b088d09f4.png https://s-media-cache-ak0.pinimg.com/originals/b2/92/a9/b292.... Your work seems related.
- radarsat1 9y agoCool!
- VLM 9y agoIf you're going to allow infinite engineering effort then I propose going all thermodynamic and having a VERY large piston connected to a small volume, change the volume and therefore pressure of a large quantity of room temperature gas, perhaps a short hydrocarbon like butane or propane or chlorine or ammonia or any one of numerous refrigerants, then the piston can vary the pressure setting the fluid level without moving anything but the piston. It may not be fast but computers can be very patient. Given some pumps and mixing vanes it could generate a ton of thermodynamic data. So toss in a piston, hit start, come back a couple days later to a 3-d model AND chemical composition data.