Why Scale Models Need to Slow Down
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- Опубліковано 5 вер 2024
- #NotWhatYouThink #NWYT #shorts
Music:
No Stone Unturned - Brendon Moeller
Footage:
MARIN
Shutterstock
US Department of Defense
Note: "The appearance of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement."
So that means you can speed up the ship and it’ll look like a scale model
I'd imagine so, yes
Speed up the ship or speed up the video? 🤔
@@positivelynegative9149 either one works
А ускорять во второй степени?
Wait, that sound genius
Lemme test few footage and enjoy my miniature model
The Navy recruiting ants for this job
@GoingTOgermany4Time is running out😢 Repent from your sins to escape judgement and obtain eternal salvation 🙏🙏🙏.
@GoingTOgermany4 hot
The 250 million year ant War is about to reach another level
god speed for these magnificent navy ants
I have some in my room they can have for free.
This man calculated how much you need to slow down footage of scale models decades before cameras really even existed
now you know the power of math: to see into reality
Well, not really cameras. I think it is similar to Reynold’s number for air flows. Essentially a unit less value that allows you to make conditions which are scaled down from the large scale. Just here they slow down the cameras because that is easier.
@@agps4418
Math and Languages
When you learn those two, a lot of it, its weird how your mind starts to perceive different, think better, remember more, etc..
You get really good at solving many problems
He was an Alien from another planet. Passing down knowledge.
That's exactly what I was thinking 🤔
How they simulated then?
Dr. Froude was the sort of man who always knew where his towel was.
Stellar reference. You seem like a hoopy frood.
@jletoniemetz you seem quite merry yourself. Furthermore, I'm impressed with your English accent.
I was going to mention he was one hoopy Froude, but you beat me to the punch, good sir.
Best internet video comment ever. Especially on Towel Day!
A fruddy grood
I always wondered if Godzilla is slow.
Time is running out😢 Repent from your sins to escape judgement and obtain eternal salvation 🙏🙏🙏.
@@idehenebenezerwhat the whar
@@idehenebenezer what
@@idehenebenezerbuzz off
@@idehenebenezer R'amen
I LOVE THIS! It's the first time I have heard of this despite being interested in models all my life! AWESOME! Excellent info.
Me too.
I remember this from my engineering degree - dimensional analysis as a tool for scaling scenarios.
Am I the Only One who Noticed That He didn't say "Its Not What You Think"😢
You're not the only one. Same here, & noticed that immediately
@@jehoiakimelidoronila5450same fr
Yeah, I noticed it too.
People complained about it so now he doesn't say it anymore
@@TimSlee1 Really😵💫😵💫 That was his signature dialouge. Very sad.
Gerry Anderson’s Thunderbirds (and stingray among others) used this fact to make their miniatures look larger, shooting everything in slow motion.
This was especially effective for scenes on water :D
But the viscosity of water always gives it away for me.
It makes it look like giant shipping containers are moving through thin hair gel instead of water.
Its viscosity and surface tension - tow different physical phenomena relating to hydrodynamics. The ship model that’s slowed down by a factor of the square root of its scalar speed plows through water with physical properties (viscosity, surface tension, and others) not have a square root relationship with velocity. So the water’s behavior “looks” different to our eye.
The result: Water movement patterns at different scales are not “self-similar”. At smaller scales, surface tension between adjacent water molecules becomes a bigger influencer of motion patterns than gravity. So, as frame rate is reduced, the motion patterns of the water look as if their big blobs of water. Looking at at a model of life-sized scale, the surface tension effect is less apparent for the larger masses of water. So the water does not appear as big blobs.
Good thing they don’t care how real it’s looks, only that it models full sized ships.
@@drink15 The David Taylor Model Basin is located on the shores of Chesapeake Bay. It’s operated under direction of the Naval Surface Warfare Center of the US Navy. Scale model ships’, boats’ and submarines’ hull forms are tested there with scale models for new hull designs. There is an associated facility for testing propellers/screws. Sensors measure form drag, wave drag and stability of any given hull form. From these tests, the hull efficiency can be determined for scale models. Froude number and Reynolds number are derived under different sea conditions and can be used after a design to reasonable accurately predict hull and propulsion plant efficiency.
The gross effects of these scale tests are usually modeled pretty well when scaled up…. except that it can only predict steady-state, non-chaotic behavior.
But for certain tests, detail matters when the physics is locally chaotic. For example, submarine propellers/propulsors are not only designed to efficiently transmit thrust from the power plant, they are also designed to be stealthy. Stealthiness is yielded when chaotic hydrodynamic flow is avoided at critical pressures and temperatures. If too much power is transmitted from the propeller to the sea at shallower depths, the boundary layer flow near the surface of propellor blades departs from laminar to turbulent flow. Water flow behaves differently than air in that air has a single phase - gaseous. Water has three phases: solid, liquid and gaseous. When the water pressure near the surface of the blade gets low enough as a result of local micro velocities at the boundary, the water can change phase to gaseous - basically boiling to localized steam bubbles at the surface of the blade. Once the gas migrates ever so slightly away from the blade’s surface, the local pressure increases and the gas bubbles rapidly collapse, emitting a very loud high-frequency sound that is chaotic across the very short time span of bubble formation and collapse. Further, lengthy duration of persistent bubble formation and collapse emits a highly chaotic set of pressure waves that can pit and erode the blade’s surface. The phenomena of rapid bubble formation and collapse near the blade’s surface is called cavitation. Again, the condition happens when too much power is transferred from the propulsion plant into the water at the blade’s surface.
This is related to dimensionless measures of scale modelling predictions in that these dimensionless numbers (Froude, Reynolds) fail to yield similar results at different scales. As a result, recent propeller design is digitally modeled rather than using scale models. Using finite element analytic techniques, the onset of cavitation can be predicted more accurately than expensive scake model propeller tests.
Under these
The radius of curvature of any “chunk” of water is effected by surface tension and viscosity , and that value has units associated with it , meaning there is a real size that is energetically or kinetically favored, so I agree it’s a fundamental give away. But to first order, the wave heights and flow can be controlled to mimic the larger scale and it probably gives you a good enough approximation.
@@davecorley5514great explanation
That's amazing!!! Humans have such potential for ingenuity!
Yup that’s kind of our whole thing. It’s what makes you and me special compared to any other form of life on this planet
@@dabbingraccoons6416 yes exactly 💯
And yet its still wrong
Aberrant. Existence is not owed us. Modern Humans are actually are a 'special needs' species rather than a special one. Our babies are born super vulnerable👶. We readily outstrip environments🏭🏭🏭. Only our slow-ish *breeding rate stops us being primate 'locusts'🦗🦗🦗.
But near to total extinction looms with every foolish political decision by a☢📡🚀 N superpower, every foolish move by a☣ virology lab or industrial food supply aviculturalist🤧🐔 or primate breeder 😷🤢🙊
Tambora, Yellowstone & Taupo supervolcanoes 🌋 might one day wipe most of us out.
Every large asteroid approaching fast from a previously unseen angle...☄
😲
(* But look up Rev. Malthus and his Malthusian growth curves! )
That’s makes so much sense now. I’ve always wondered why scaled down models like these were ever made cause they seemed to act completely different to what would happen in real life. Knowing you just need to slow down the footage by a certain amount makes them actually make sense lol
you learn something new every day
This is something we'd all want as a kid....or adults
Uhhh, Reynold's number. L * V / v
L == representative length
V == Velocity
v == viscosity
Objects with the same (or similar) Reynolds number will behave the same (or similar)
For high Reynolds number, resistance is proportional to minus velocity. For low Reynolds number, resistance is proportional to velocity squared.
Wow, I remember all this from 1974. Wow.
It's rewarding to see folks remember things from 74 etcetera however, not being as educated with these laws I'm compelled to ask you (out of ignorance) what is your point here and what you're trying to tell us ?
The other way around.
At HIGH Re number the resistance is proportional to the square velocity.
And another point:
The Re number is
Re = V × chord / nu
Where nu is the dynamic viscosity
nu = viscosity/density
Y eso es lo que nos enseñan en la Universidad Mayor de Sán Andrés, La Paz, Bolivia 🇧🇴
Not in Bolivia , North Carolina
@@Arturo4586 You might be right at that. I learnt this in ..... 1972, then again in ... 1974, think, and never used it. Your formula is the same as mine, just uses a slightly different word. Cheers.
@@billvandorn5332 It's what we use to help us ensure fluid behaves how we would expect at different scales. It's critical in the engineering of scale models for analysis. Much more so than simply slowing down footage. That is simply one piece of the puzzle.
Impressive. But can you remember where you left your keys, your sunglasses and what you were supposed to pick up from the store? 😅
I love math solutions like this. Thanks for the video.
You can use the Buckingham Pi-Theorem to find out which dimensionless parameters play a role in model sized experiments (in this case the froude number is on of these) and recalculate the numbers with these dimensionless parameters which can be expressed as equations, like mentioned here. That’s how they came up with the idea of using the froude number.
I had these in process engineering on University . Until you know which physical parameters could be involved in what you want to analyes, it is straight forward.
I was about to say. We had a class of fluid mechanics, under which we studied the theorem. Some of the relationships can seem counterintuitive until solved, especially with geometric, kinematic and dynamic singularities.
Nerd
You just gave me spicy nostalgia of Pi-groups at university.....
Unnecessary obfuscated repetition .
The variable is a separate equation within the overall equation.
They must've used that method to film some ship scenes in movies with practical effects before CGI became more common.
Thinkin' the same.
Yeah, dioramas were often used for mainly war and action movies.
Understand that they use 1/3 size models since it's more realistic.
@@pushpakumardaniel3751 Scale depends on the budget. Bigger models look better but cost more.
@@johnbaker1256
Thanks. 🙂
Love this...! It's all in the numbers...! STEM is critical...!!!
What a generic statement. Of course learning is critical. 🤦
Unless one just need an OF to get rich and "successful"...
@@ericyeahbaby3875 imagine talking about stem and thinking that bringing up OF means anything
Hey. I haven't done anything to any of you, so there's no need to talk about me like that 😢
"Identical" is a bit of a stretch. In scale model simulations you just try to identify which flow parameters are most impactful and which ones might not matter as much. The scale model results will never be identical, but figuring out how to optimize the conditions is by no means a simple thing, and a lot more math goes into it than just changing the timescale.
That's just science in general. There's always another factor.
@@alexrusset8614 And while I don't think it's necessary to go more in depth in explanation, the narration also should not make the implicit claim that there is no further depth to go into.
I found the information quite interesting and might make a ship model and use the formula stated. While that would be fun the bots that flood comments are not.
Blame UA-cam
the boat at 10 seconds is being towed at my old university towing tank
It’s a prediction. And that’s it, there are still a ton of forces which cannot be modelled effectively by this principle alone.
The core one is vibrations. Something the Yanks didn't predict with North Carolina and would plague every other battleship they build after. Model Basins couldn't have diagnosed that problem.
@@GrasshopperKellycould you explain that in greater detail?
@@alexandremontoya9777 As a ship pushing through water, the friction along the sides, as well as the wave form along the freeboard at the bow causes vibration due to synchronised resonance. The flexibility and rigidity of the hull in varying places increases and decreases the vibration problem.
The higher the speed, the stronger the vibration. With examples like USS North Carolina, it can be so severe, more fragile equipment on board can be affected or even broken. It can affect targeting on a gun armed ship.
Engines and firing armaments also cause vibrations. Which all affects targeting, but the USN didn’t predict just how bad it would be on NC.
The 2 core effectors are the shape (form) of the hull and speed. People weren’t building 28+ Knot battleships before the 1910’s (couple of small exceptions with battlecruisers in the 1900’s).
Another issue on top of damage is noise… it can make life onboard a battleship unbearable if you’re cruising halfway across the Pacific to intercept a target in a few days. People get used to the typical noise on board but some Battleships were notorious. Take Ocean liners as another example, passengers don’t want to spend days/weeks on the water feeling and listening to the hull vibrating.
Many ships were refitted with different bows, some multiple times, were reinforced in sections, or other dry-dock measures were taken to try fix the issues after sea trials.
Because Scale models are affected by (relatively) larger water particles, different scale water surface tension, and different construction defects (scale models don’t have “oil canning”, where the hull expands and contracts from temperature and the external water pressure between the bulkheads, sections and frames).
Model Basins can however help reduce the wave form, which also reduces drag, and so vibrations too. Ocean Liners had bulbous bows fitted to counter the wave form along the sides. Because drag means fuel efficiency and speed. On top of comfort for passengers.
@@GrasshopperKelly Great point!
A few more I can think of:
- boundary layer effects and wake turbulence on larger structures.
- viscosity and surface tension (albeit this can be modeled in certain ways)
- Froude scaling: Froude scaling does not account for viscous effects which are governed by the Reynolds number, this is not a linear scale and negates discrepancies in drag and other resistance characteristics.
- cavitation and ventilation of large structures.
- structural responses under a load factor of 100 the simulation.
It really goes on endlessly. This is why we follow up the tank process with CFD.
And I thought I was clever after developing my own equation to get accurate dosages in my weed brownies.
You're a hero in my book 🥺🥺🥺🥺
You're something of a scientist yourself I see😁
Haha! That's funny! 😂
Model testing is fun. Good old Froude and Reynolds number scaling.
When Froude's wife screamed out "Ian!" instead of "Froude" the other night, she did what became known as a "Froude/Ian Slip."
I don't know whether to groan or applaud..
Terrible
This is amazing, as a previous architectural model maker I would never have guessed there was a formula to mimic the scale differences just by slowing down the operational footage of the model ships... Thanks
They just need to create a 1:1 model to test those things
They should do 2:1 models and speed it up by its ratio squared.
You're right, way easier than all that extra math.
I was guessing the density of the water would need to be changed but truth is more wonderful than fiction! 🎉
This is the attention to detail that makes some movies better than others when using scale models for destruction/wide scenes. It matters a lot.
Just reminds me of that documentary i saw on Thunderbirds, where they addressed this problem with models, but then had to shoot at a higher frame rate with a shorter exposure.... Which meant they needed giant lighting rigs to pump in enough photons for the cameras to pick everything up properly
...if you build a big enough ship, time will stop!
We briefly learned about this in my undergrad fluid dynamics course, the prof even had us run some scale model tests ourselves. Was a fun topic, cool to see it again.
That scale model container ship is cool as hell.
They should make 2:1 scale models and speed it up by its ratio squared.
Froude was the first who devised a test tank procedure by which it was possible to correctly scale up the required power to propell a full size ship from model ship tank testing.
As some other commenter already mentioned the laws of similitude are derived by transforming the governing equations of motion in fluids, which are the Navier-Stokes Equations (a set of non-linear Partial Differential equations which until today cannot be solved mathematically by integration) to a dimesionless form.
Then the NS Equations exhibit three non-dimensional scaling laws of which one is the Reynolds Number, the other the Froude Number and a third which I have forgotten.
As it turns out for model testing only fulfilling Froude's Law/Similitude is practical so that the ship model is towed in a test tank at Froude's speed while measuring the forces it has to excert to overcome the resitance.
At Froude Speed the wave pattern along the ship's length is similar to this what the full size ship would form when also run with the same Froude Number (Fn)
Actually in the video was quoted the _wrong_ Fn which contained _h_ for water depth. The _correct_ Fn for ship model tests to apply would be
Fn = sqrt( V / g / L ) where V is the ships speed in m/s, g is the Earth's mean gravitational accelaration, and L the length of the ship in the waterline.
To compensate for the negligance of the Reynold's Similitude/Number (Rn) during towing tests, its partial frictional resistance is extrapolated by the ITTC correlation line or function.
ITTC stands for _International Towing Tank Conference_ .
Today Froude's test procedure is only slightly enhanced and modified and is outlined in the _ITTC Power Prediction Method_ , or similar if my memory serves me correctly.
"NS Equations?" 🧐
This is the problem of scale which effects all models, not just ships. Model railroads are more prone to details because the weight of the cars is much smaller than the scaling. And locomotives can't pull 100+ car trains because the "tractive power" mostly determined by the weight of the locomotive on the drive wheels is much smaller than scsle.
Have you ever seen an operating scale model roller coaster? They zip through the ride way faster than scale speed.
Have you ever thought about why ants have skinny legs and can lift several times their body weight yet elephants have thick legs and can only lift a fraction of their body weight? Not all quantities scale up or down at the same rate.
Oh, that explains it! Physics is so fascinating, even for knuckleheads like me.
So true. Gravity itself is not affected by scale, but obviously distance is. So is molecular density. Other rules of physics as well.
Ima ask the navy if I can play toy boats too
That guy was one Hoopy Frood
1985s Raise The Titanic that scene where it comes up out of the water looked so good because they shot that model at a very high speed then slowed down the footage and it gave the model a weight feeling. It looked like a big ship coming up out of the ocean. Models can be fantastic if shot correctly.
Was not aware of the Froude scale before. I learned something new today. Thanks.
Just to be clear:
The full-size ship IS moving up and down at the same speed as the model, it just LOOKS slower because of it's massive scale.
For the model, the ship is smaller, lighter, and the waves are smaller. So the ship bobs up/down over less distance (relative to the human eye).
If you scale this up, the ship is bigger, heavier, waves are much larger, but the speed at which the ship moves up/down is the same, it just LOOKS slower because the larger scale means the bow & stern cover more distance (model might bob a few inches, real thing might move dozens of feet).
There's also the Navier-Stokes equations. To accurately predict you may actually have to change the SHAPE of the model as well.
Many people don’t realise the oceans are just really big puddles. We’ve yet to make a big enough jacket to allow ladies across yet so the airplane was invented
We're only bad luck on a ship; if you don't bring along our girlfriends.
basically its because nothing can be truly upscaled properly. this is the best way to get it done as close as possible to what its going to be.
Very informative 💯
Appears to me that there needs to be a snow plow on the front deck of the ship!😊
It seems to me that it isn't only about speed. The relative viscosity of water compared to full scale vessel size must also affect a small scale model differently.
Can you scale down viscosity of water, how if you can?
@@Lasvegasnowman1 That's my point. You can't, which makes me wonder how relevant model testing is in water, even with slow motion photography. Better than nothing I guess.
@@joewoodchuck3824 Right but with today's computers they could model it btw how much wood could a woodchuck chuck if a woodchuck could chuck would woodchuck would chuck all the wood if a woodchuck could chuck wood 🪵🪓 ROFL 😭🤣
@@Lasvegasnowman1You can do this with surfactants or wetting agents. The water's surface tension is reduced, creating smaller droplets and aiding the illusion.
@@joewoodchuck3824 what you’re talking about is Reynolds number effects. It’s the ratio of inertial effects (the mass and velocity of a “particle” of water) and the viscosity of the water. It’s why the real ship has a fine spray while the model has big blobs of water, viscosity is affecting the model more than the real ship.
this would be useful not only for ship models but also plane and car models. you see car models going like 600 km per hours.
They actually do this with planes nowadays in Wind tunnels
Froud was a genius
That's actually a really cool explanation. I definitely learned something today!
That's pretty cool
What is missing from the video is that the speed of the water here needs to be sped up first, and then the footage can be slowed down.
Or alternatively, using a denser fluid to simulate the same expectations.
Genuinely, years of wondering came to an end today.
Very clever formula.
They can also add washing liquid to water to reduce the viscosity and make the small scale model look bigger
great clip- This problem is so much bigger with model planes!
I thought that carrier would be a model. Well done.
I was smiling ear to ear watching this, I love your goofiness and happy Mother's day everyone
Thanks for reminding me of my times on ram. On the list 90% of the time. 11/10 great time
Fluid dynamics calculations don’t need video. You only need the size ratio and fluid stream velocity ratios.
Apparently it’s common for a few shipping containers to fall off the top of the stack now and then in rough seas. That basically means there are lines of of shipping containers crisscrossing along the ocean floor under frequently used shipping lanes. This is something that has actually been happening for over three thousand years in some parts of the word. Especially the Mediterranean. Ships from all the various empire that rose and fell in that region. Egypt, Greece, Rome, Persia and so on. Crazy to think about.
And people go off at science pages online 'bUt ThAtS jUsT a ThEoRy'
That mathematician was one hoopy frood
This is something that movies can’t seam to get right, whenever they are trying to show somthing massive moving like a skyscraper falling they always have it going to quickly and it makes it look cartoonish
Very interesting and informative, thank you.
The moment he stops saying "Its not what you think" is exaclty when its not what we think.
Highly genius highly underestimated insight.
how? math....
I always wondered about this, especially the wave size and how differently small waves (scaled down)act to large waves(irl)
that man was a genius
This is extraordinarily profound
Space / Time
Relatively
So as things get larger , they slow down
That is the only way
As things go faster , they increase in mass volumes/ slowing them down
Scale: ratio are in constant fluctuations
There is something much more powerful of an idea happening here .
Or the powerful idea happening here is fluid mechanics. Also know one knows what the hell you are saying “they increase in mass volumes/ slowing them down”
@@gopackgo4036
Then why don’t you just change the viscosity instead of slowing down the fucking film
@@gopackgo4036
2 maybe 🤔- others people here can think for themselves?
And
Don’t want to hear any stupid nonsense from non academics?
What are your scholarships and credentials?
@@user-db2fb1db1m my credentials are a masters in mechanical engineering with a thermo fluids focus. I can barely understand a thing you are saying, and you are basically just putting out a string of unsubstantiated and barely related points. The reason you would not adjust the viscosity is (1) it’s much more difficult to find a different fluid than just slow down the model/fluid and (2) you’re messing with the flow inertia in ways that are difficult to predict and aren’t studied.
@@gopackgo4036 see if you can comprehend this…?
Go eat a 2 pound bag of shit
And then , tell me how much comes out the other end and … please do take accurate measurements and then figure out how much mass : energy ratio was lost
Thank you
Didn't know about the Froude number, thanks.
Congratulations to the engineer who found the circle in the square...😮
makes sense, scale down size -> scale down time
and the scale factor is "g" as in 9.8 meter per second squared, hence time catches a square root.
@@DrDeuteron oh that's make sense why blackhole can speed up time if you approach it
If you've never seen a large cargo ship loaded with 40' containers, it's HUGE.
There was one of these massive wave pools in Richmond California as part of the industrial War complex there. It was decommissioned quite some time ago but from what I understand now they are simulating an atmosphere of one of our neighboring planets
Very interesting, thanks for sharing. 👍
that last boat just got molly whopped
A lot of people don't know this about our first nuclear aircraft carrier. If I remember correctly there were three reactors on board the Enterprise. Since they had all this excess energy they wanted to see in the real world how fast can an aircraft carrier go. Add the speed was increasing the sailors and engineers started hearing a noise from the bow of the ship. They were able to see and measure that the bow of the aircraft carrier was trying to fold itself in from the force of the water.
They had to go back to the shipyard for some repairs. They would not say what the speed was and even to this day they keep the information on how fast the carrier can go.
When they realized all the power they were having that's when they decided that they did not need all the extra nuclear reactors. And of course today they have ways to figure out long before the first piece of steel goes down on how much power they will need.
It sometimes amazes me how the universe obeys these precise mathematical formulas...
Theres a method to do this on all types of engineering problems, known as the Buckingham Pi theorem. Look into it if you want to do this on more than just boats
Yeah, that's not quite true. You can't scale the water, its viscosity and mass need to be taken into account too.
The Froude number already takes care of that. What the video is describing is Froude number scaling for liquids.
The Froude number is the ratio of inertia against gravity, so mass is already taken into account, since inertia is directly proportional (related) to mass
The Froude number does NOT take into account viscosity. It is bound by the Reynolds number which is not a linear scale. The only thing Froude scaling is concerned with is gravity and intertia. The viscosity comes from the Reynolds number. You must also scale the Reynolds number in a proportional way. The Reynolds number scales the ratio of viscous forces to inertial forces in the fluid flow.
@@skunkwerx9674 oops, you're right
@@hm-mt3wj sorry if the NOT was a little harsh. I also thought it was covered by the Froude number. You could scale it, but because it’s an ever shifting value it’s incredibly difficult to pin down in reality in a directly analytical way.
@@skunkwerx9674 It's ok! I
I'd rather get corrected than live in ignorance
I thought this was a response to that RCTestFlight video where he turns the model aircraft carrier into a hydroplane
I’ve wondered this for probably 15 years
I heard that not a coincidence (nautical incident) line, awesome delivery of a joke
There's no need to ask this question. The man just calculated the number. The principle itself should speak for itself to everyone.
There’s a creator here on YT who uses this principle (and some sound design) to make RC monster truck videos look real. They’re really convincing, at least until the truck performs a quadruple backflip
Not only the Froude number which gives the same wave pattern , but for the sea the Pierson - Moskowitz sea spectrum must be scaled accordingly.
I never heard of this before but its awesome!
Also useful in Aerodynamics for water table testing if the real model is supersonic
Would you also need to decrease the viscosity of the liquid?
We have same problem with « scale » RC cars… Especially crawlers, because a lot of suspension bumps…
impresive
It should have been called the Kaiju Equation.
Square root of the scale. Got it. Brilliant
I hate running out of fuel or power off shore..and that rowing!:)
Why don’t we just use a more viscous fluid for the smaller models?