Graphite and water - Now add magnets!
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- Опубликовано: 29 сен 2024
- A simple educational tool in fluid dynamics. Graphite flakes make a beautiful rheoscopic fluid. The flakes also react to a magnetic field, aligning with the field direction.
Combine these two phenomena and you can produce interesting flow models and even streamlines around objects like cylinders and airfoils. Cylinders produce the well known Von Karman vortex patterns.
Chapters:
0:40 Magnetic effect on floating graphite
1:40 Magnetic effect on dry flakes
2:24 Magnetic effect on rheoscopic fluid
3:08 Halbach arrays
4:00 Flow around cylinder and ellipse
5:30 Making streamlines
6:07 Flow around a NACA 0020 airfoil 
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What a brilliant use of the graphite. I never thought to use magnets to look at hydrodynamic flow. When I wanted to, I always imagined I would have to build some very complex tunnel. But the simplicity here is so satisfying.
Excellent !!
I've always been attracted to magnets and their sometimes invisible effects, even on non magnetic devices or products.
The section on NACA profiles is very interesting.
Attracted to magnets. I see what you did there 😂
Very interesting ! I wonder how this rheofluid will interact with electric field or a moving magnet (in rotation for example). First time I see non magnetic particles in suspension interacting with a magnet ! Thanks for sharing these experiments.
Your physical experiments are interesting.
Plz continue the development of MHD thruster
I wasn’t aware that graphite was magnetic at all since it is almost entirely carbon. I’ve got a few jars on hand, so I guess I’ll test it out.
Bravo!
I thought graphite was diamagnetic. Is this showing graphite to be ferromagnetic?
I am still trying to understand it myself. I doubt that it is ferromagnetic in any way. I never saw any attraction or repulsion along the field gradient but the magnetic moment is evident even at some distance.
@@williamfraser From Physics World: "Now, Kees Flipse and colleagues at Eindhoven University of Technology and colleagues at Radboud University Nijmegen have shown that the magnetism occurs in the defect regions between the carbon layers." Did not realize it but this is an open area of research! Thanks for sharing your experiments. Nice.
Nice idea dude!
@SmarterEveryDay wants to know your location 😂
Billy... You sound like your wife left you just after your dog died. That or you're about to ask John McClain what he did with your detonators.
Are you absolutely sure that that's graphite? Maybe it's pyrolytic graphite?
Really cool and practical visualizations of magnetic field minima using the diamagnetism of graphite. The "painting" of the fluid orientation at the end to show streamlines is really clever.
это так же работает с алюминиевой пудрой
The combination of those two effects to produce a flow model is amazing! I'd only really seen this effect in digital simulations, this is mesmerizing and can be super informative, well done!
Now add a rotating magnetic field.
A low-frequency AC field?
And heat source for convection
This experiment is used to demonstrate fluids, not so much magnetic fields.
I you want to see that, just look at a time lapse of world weather. The tropics and equator clearly show the atmosphere interacting with the magnetic fields.
The same can be said about the butterfly diagram created by sunspots.
This is absolutely fascinating! There are so many possibilities just from super simple experiment involving water, graphite and soap. Add magnets and a airfoil.... dang. I think I am more blown away from the simplicity than anything else.
Hats off, GREAT job.
Visualising the invisible. Very good.
I've been working in hydrodynamics for a while now. This was a fascinating demonstration.
Ah, that explains the recent graphite pollution in the Amazon. Did you really need to investigate that huge river this way?!
Besides, how else would you do it? What is so special about this? We did this at school during the EIGHTIES! That is 40 years ago. What schools did you attend? For real!
@@voornaam3191 Troll.
Very interesting
Many many thanks and honors to you man, it's genius. Wonderful visualization of MAGNETISM.
Amazing!
So happy to have found your channel and a fellow experimenter!
Really impressive way to visualise fluid simulation
I'd love to see the water traced up and down (instead of left-right) with the array a few times then have the wing go through without magnets to see how the wake influences "walls" of air (as opposed to emphasising how "layers" of air flow over the wing)
Excellent idea! It will show flow velocity much better.
It would be nice to see a cross-sectional view. Using magnets to make both vertical and horizontal lines.
Neat! What are the Reynolds numbers?
For the airfoil, ballpark 10k - 15k . Assuming the flakes did not change viscosity.
Awesome :)
I knew about Rheoscopic fluid, but this is a very interesting variation (Also different color) !
Granted there is the issue of corrosion, but iron filings in rheoscopic fluid now has me intrigued as well!
Granted from just an art perspective too the color may be of use.
Also i love the concept of using Carbon (Be it Carbon Black, Graphite, Graphene, Carbon Fiber, Carbon Glass, Carbon-Carbon Composites, Carbon Felt) in designs as it is semi-renewable, so this is ANOTHER application it seems!
Magnetorheological fluid use small ferromagnetic particles (larger than those in "ferro fluids"). A magnetic field is then used to change the viscosity.
I like this video Very Much .
That's pretty interesting. Thank you. 👍
That final demo is an odd mix of a “Towing Tank” and a Wind Tunnel!
What a brilliant way to visualise flow!
This is so amazing ! This should be shown (and played with) in every school !
Magnets and water reminds me of something we did in the school lab with iron filings. Too long ago, so not sure if it has anything in common, with this illustration!.? 😂
Absolutely right, iron filings also align with the field direction. The principle is slightly different, each iron filing gets magnetized and behaves like a mini compass.
@@williamfraserThanks, I thought so, too
awesome visuals! how about putting sound waves into the mix?
Nice video and presentation.
I wasn’t aware of graphite interact with static magnetic field.
I think it has to do with diamagnetism.
Beautiful art.
Unquestionably absolutely brilliant!
My favorite part is the voilà
Edit: my favorite part was the awesome turbulence visualization
wooo 🤯
Perfect for teaching fluid ,aerodinámica efectos etc.Great a very cheap.
I had no idea about graphite and magnetism!
Brilliant!
No one knows it completely
Guys Tesla Vaulve : LOOK AT THE PATTERS >>>ITS TESLA VAIVE LOOK AT THE PATTERN IT LEAVES
Many thanks for taking the time and effort of making this video and sharing Your knowledge and imagination :)
Videos like this is one reason why I still love RUclips, finding "gems" like this where people take their time and effort to make a video to show me something interesting that I never would have seen or even thought of otherwise.
Best regards.
right? seeing stuff like this is so much fun! two minute papers features a lot of fluid simulations and i never thought I'd see someone make a simulation fluid xD
There was a video of a guy making his graphite dance with wifi fluctuations
*@William Fraser*
The water experiment at 5:00 - ish, made me think of another video, called: "Motion Extraction" by channel "Posy", starting at the time: 1:12 Enjoy :D
Cool video, thanks for pointing it out.
@@williamfraser You're welcome.
I would have posted a direct link to it if I could, but RUclips deletes all comments with links in, even to their own site :/
Wow that was amazing, could that be used instead of a wind tunnel or is that already done.
Rheoscopic fluid can be used to study Taylor-Couette flow, alternating bands of turbulence between the walls of concentric spinning cylinders. At slow speed the results might be useful as a wind tunnel substitute. At higher speed the object will create a "bow wave" and divergent waves, just like a boat. So to create a wind tunnel equivalent you would have to eliminate the free surface between water and air. I have tried it with a glass pane on top but immediately realized a problem. Any flow against the glass creates a boundary layer and the shear turns all the flake parallel to the glass, just like window blinds, effectively blocking the view deeper into the fluid.
This is brilliant. This is fluid dynamics PhD level stuff.
Such a low effort way to get a thin slice of a wind tunnel. you could begin extrapolating data from between the slices. Hmmm, if you set another complementary array of magnets on the bottom and used a clear panel on the bottom you could record the results form both sides, and use a thicker slice (deeper fluid) and get two valid data samples at once, so as to test a tapered shape or wing design!
Flow against a glass pane becomes opaque. The boundary layer shear turns the flakes parallel to the pane, just like a Venetian blind. All you see is silver and a small amount of turbulence.
@@williamfraser Both interesting and disappointing at the same time. I was thinking about using thin vertical tanks, with mags and cameras on the sides, but this info kinda poops on that parade.
Not all graphite is magnetic, so, which specific supplier sold that? Also, I think the dead black powder won't work, and instead you need shiny graphite "flake," so the particles will align with shear. (Physics teachers trying to duplicate your demonstration for classroom use ...they might buy the wrong graphite!)
Also, search "Magnetic graphite" video by Robert Murray-Smith, where he found that running common graphite through a ball-milling process can unexpectedly make it magnetic. But that's a lot of needless labor, if someone is manufacturing the already-magnetized graphite!
Using detergent as an emulsifier is pretty cool....
I use baby oil with fine steel wool chopped up and paint the back side of bottle white. Gives very nice view of magnetic fields
Does it show the field in three dimensions?
Just telling what I've done try it out
Cool this reminds me of those old airfoil videos from Prandtl
Elegant
That is kind of interesting. Might be handy for hobbyist level R&D stuff (seems relatively inexpensive), or at least trying to get a look at how some things work.
You're creating new worlds ...
This makes me wonder if it'd be at all possible or useful to generate electricity using rotating magnets and the rheoscopic fluid, and curious how it would specifically behave compared to typical generators, if it would work at all.
It is theoretically possible, but it would not be a practical or efficient method for generating electricity on a large scale 'apparently'.
@@pa_maj.MARTINI-van-MANif possible to contain and save it, then any little bit, would help. Here, I'm specifically, thinking of keeping my phone charged, during our extended loadshedding (SA power outage crisis) 😂
@@tessasinclair6315 What's going on in SA with power is quite bewildering since there was two major power stations (Kusile and Medupi) having been added to the grid. There should, because of this, be no problems with power...corruption springs to mind Tessa, nothing new.
You'd probably do well with a small solar panel that charges mobile phones and other USB equipment, you get Good sun.
If you can charge up a small power bank during the day, you could charge from that same power bank at night.
A 50 watt solar panel that already has a connection to USB would be plenty, and a 15 watt panel would be the minimum but very capable in sunny conditions; especially for charging a phone and small power bank.
Nice display of Magnetic fields and drag. Any functional purpose to this other than aesthetics?
Possibly changing fluid viscosity using magnetic field orientation.
Super! Thank you very much!
What is a huang array
Halbach array..
A way to arrange magnets so there is a stronger field on one side.
Much better if you search for images.
Super cool man! Excellent job! It’s mesmerizing watching the graphite get aligned by the magnets and then the turbulence from the foil profile.
Could this technique be the death of wind-tunnels? So much cheaper!
It might have niche applications but is otherwise very limited compared to proper wind tunnels.
Oh boi, so happy i've came here... was really wondering if it's possible to get a rheoscopic fluid somewhere, but couldn't imagine it'd be that easy! Thank you very much sir!
Awesome, i never realized graphite would react with magnets. I think what makes this so awesome is the semi reflective propertues of the graphite and fine enough graphite stays in suspension much better than other magnetic substances so it becomes a very good visualizer for fluid dynamics. So simple i could do this right now. Thanks for some inspiration, i may test a few ideas this has brought to me now.
Love this experiments...
If you can, what is it about the patterns in the fluid that a person can design a better wing
The flow patterns seen here do not translate directly into what you will observe around a real wing. But for what it is worth, a cambered (curved) airfoil will likely have less separated flow over the top surface at high angles of attack.
Fokken interessant, dankie.
This is the most amazing thing ever. You basically have yourself a DIY wind tunnel to study fluid dynamics
If you want to produce more “lift” WITHOUT increasing “the angle of attack” and the DRAG this produces, just hollow the upper part of the airfoil profile just after the peak of the curve - this will produce negative pressure while the lower side glides smoothly.
Making an MHD dynamo is simple but prohibited (hidden). For this, you must make the liquid you use rotate in a vortex shape. Then, when you charge it with high voltage, you get a very high electric current. The output is in the mega watt range. It charges completely from gravity. If you want details, I can help you.
Great presentation. Thank you. Please do a demonstration of the field around a loudspeaker voice coil 🙏🏻
Total Solar Eclipse in our electro-magnetic firmament.
Tesla: "Energy, Frequency, and Vibration."
Magnetism in graphite is entirely unexpected to me. Why would graphite behave this way? Is there anything about graphite that should have us expect it to be magnetic?
It is supposed to be diamagnetic as far as I know. The layered structure of graphite might play a role in what appears to be unexpected behavior. I am still trying to figure it out myself.
@@williamfraser Diamegnetic means repelling or fleeing magnetism right? Or perhaps it is directionally diamagnetic and only resists magnetic flux in a certain orientation. If magnetic field lines cross the delocalized pi-orbitals which give graphite its electrical conductivity, and this induces a current which faces electrical resistance, maybe this has something to do with it.
Briliant! Such a simple model for such a complex thing. However, the graphite filler is a lucky draw- by default graphite is not magnetic, just tested it. There's some ways to make it a bit magnetic, but it sounded not trivial from googling (heating above 3000C° or nitric acid or other tricky methods). Looks like your graphite filler was unintentionally made magnetic- can you please share what you exactly used? I wonder what they did to make it magnetic.
I bought a tub from AMT Composites. No grade specified on the container.
That’s what I expected too! Maybe an infinitesimal amount of diamagnetism is enough? I also thought that graphite was uniformly absorptive of light, but these are flakes with a specular surface!?! Maybe the stuff they make for composites is intended to be structural… not isotopic.
@@williamfraser Thanks ! I found on their website an "metallic-powder-graphite-30g" but the tech datasheet or safety datasheet links aren't working..probably would need to mail them to get this info. My 5cents for now are, this might be "pyrolitic graphite", a graphite version that has crystallized slightly after heating above 3000° and has magnetic properties- and is sold industrially, I have seen cheap packages sold.
Since I heard from the "supercell ferrofluid" I search for an cheaper alternative to observe and understand magnetic fields, I think this could be an option, really cool, thanks!
THIS IS SO FREAKING COOL!!!
Much better than other setups I’ve tried
Sunlight liquid 💪💪💪
I’d like to these with rotating magnetic fields of different configurations. Also could you make make a rig to visualize the eddy currents from toroidal propellers?
This is very cool.
The path left from the circular round magnets dragged along, resembles quite interestingly the one-way valve design of Tesla.
Diamagnetism of Graphite is the key of the effect!
Some graphite does appear to be paramagnetic (attracted to magnets.) See "Magnetic Graphite" on Robert Murray-Smith channel. On the other hand, pyrolytic-grown graphite is strongly diamagnetic and repels magnets, not attracts as seen in this video.
I wonder where he bought it. It shines, so it's probably "flake" and not the black "powder" form. Chances are, if we just buy some random graphite epoxy-filler, it won't display any magnetism effects.
Looks like a good way to study weather.
The angled wing also made what looked like a tesla valve.
Well spotted.
6:38
Very nicely demonstrates the turbulent flow over the wing in a stall.
That was so cool
Nice work, some macro shots of the fluid in motion would be fascinating to see
👍👍
Superb. Accessible to high school classes and useful at university level. This should be more widely shared
They're not repelled from the area where it is clear of the graphite, but rather they are attracted to the area of more denser graphite.Concentration.It's not a matter of pushing away but a matter of pulling stronger to the points
Beautiful!
A brilliant demonstration! I will be sharing it with my Physics teacher niece.
You need to get the future Blackmagic 140mpx cine camera.
Wow well done! It makes me want to redo some MHD experiment now.
Amazing
Alright man my brains been blown.. its all over the ceiling.
Yeah.
Very interesting. Fluid dynamics, less drag😮
What a beautiful method for showing vortices.
This beautiful and creative approach completely replaces (homemade ) wind tunnels with smoke trails or threads for 2D flow visualization. I will reproduce this but play with adding viscosity to change the scaling and reduce the small scale eddies. Thanks for the inspiration!!!
Try Deoxydene. It might sell under different names but hardware stores sell it as a rust remover. It is mostly phosphoric acid and contains surfactants so no additional detergent is needed.
I think I just saw three dimensional airflow. 6:30
Hey does anyone notice something 4:30 secons look at the patteren thats teslas vaulve
Excellent demonstration, on several levels.
This is one of the coolest videos I've seen for a while