Tempest in a teapot: International team of scientists describes swirling natural phenomena

Vortice in a teacup, from the worldisround.com - click

Via press release: (Santa Barbara, Calif.) –– Scientists can use cylinders as small as teapots to study the mechanisms involved in powerful hurricanes and other swirling natural phenomena.

The earth’s atmosphere and its molten outer core have one thing in common: Both contain powerful, swirling vortices. While in the atmosphere these vortices include cyclones and hurricanes, in the outer core they are essential for the formation of the earth’s magnetic field. These phenomena in earth’s interior and its atmosphere are both governed by the same natural mechanisms, according to experimental physicists at UC Santa Barbara working with a computation team in the Netherlands.

Using laboratory cylinders from 4 to 40 inches high, the team studied these underlying physical processes. The results are published in the journal Physical Review Letters.

“To study the atmosphere would be too complicated for our purposes,” said Guenter Ahlers, senior author and professor of physics at UCSB. “Physicists like to take one ingredient of a complicated situation and study it in a quantitative way under ideal conditions.” The research team, including first author Stephan Weiss, a postdoctoral fellow at UCSB, filled the laboratory cylinders with water, and heated the water from below and cooled it from above.

Due to that temperature difference, the warm fluid at the bottom plate rose, while the cold fluid at the top sank –– a phenomenon known as convection. In addition, the whole cylinder was rotated around its own axis; this had a strong influence on how the water flowed inside the cylinder. Rotation, such as the earth’s rotation, is a key factor in the development of vortices. The temperature difference between the top and the bottom of the cylinder is another causal factor since it drives the flow in the first place. Finally, the relation of the diameter of the cylinder to the height is also significant.

Ahlers and his team discovered a new unexpected phenomenon that was not known before for turbulent flows like this. When spinning the container slowly enough, no vortices occurred at first. But, at a certain critical rotation speed, the flow structure changed. Vortices then occurred inside the flow and the warm fluid was transported faster from the bottom to the top than at lower rotation rates. “It is remarkable that this point exists,” Ahlers said. “You must rotate at a certain speed to get to this critical point.”

The rotation rate at which the first vortices appeared depended on the relation between the diameter and the height of the cylinder. For wide cylinders that are not very high, this transition appeared at relatively low rotation rates, while for narrow but high cylinders, the cylinder had to rotate relatively fast in order to produce vortices. Further, it was found that vortices do not exist very close to the sidewall of the cylinder. Instead they always stayed a certain distance away from it. That characteristic distance is called the “healing length.”

“You can’t go from nothing to something quickly,” said Ahlers. “The change must occur over a characteristic length. We found that when you slow down to a smaller rotation rate, the healing length increases.”

The authors showed that their experimental findings are in keeping with a theoretical model similar to the one first developed by Vitaly Lazarevich Ginzburg and Lev Landau in the theory of superconductivity. That same model is also applicable to other areas of physics such as pattern formation and critical phenomena. The model explains that the very existence of the transition from the state without vortices to the one with them is due to the presence of the sidewalls of the container. For a sample so wide (relative to its height) that the walls become unimportant, the vortices would start to form even for very slow rotation. The model makes it possible to describe the experimental discoveries, reported in the article, in precise mathematical language.

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The other UCSB author is postdoctoral fellow Jin-Qiang Zhong. Additional authors are Richard J. A. M. Stevens and Detlef Lohse from the University of Twente and Herman J. H. Clercx from Eindhoven University of Science and Technology, both in the Netherlands.

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ShrNfr

Truth is what works. Now make some predictions and we will check how good your model is. However, from my undergrad days, I seem to remember that once you get out of the region of laminar flow, things be come, shall we say, a bit difficult.

Les Johnson

OMG!
They have discovered the Coriolis Effect!!!

Peter Walsh

Quote from start of article
“The earth’s atmosphere and its molten outer core have one thing in common:”
Maybe Inner Core???
Peter

jack morrow

Wow, what deep,intriguing experiments. Takes real “scientists” to come up with yet another hair brain model. Where do all these people come from? I’m sorry, but I seem to have lost faith in the scientific community as a whole.

Douglas DC

Reminds me of a Jr. High science experiment I did .-On the Coriolis Effect?!!
Gee and I could’ve applied for a grant. I won’t go into the kid at the next
Table who tried to re-animate a frozen Catfish. Found in ice at a local lake.
Should’ve written a paper on attracting cats…

Kev-in-UK

ShrNfr says:
November 30, 2010 at 9:12 am
well said – but I suppose there should be enough expertise in CFD by now anyway? (computational fluid dynamics).

maksimovich

The tealeaf paradox is used in one of Einsteins most famous papers as the proof of Baers law eg http://en.wikipedia.org/wiki/Baer%27s_law and the meandering river problem.
Albert Einstein, “The Cause of the Formation of Meanders in the Courses of Rivers and of the So-Called Baer’s Law.” Die Naturwissenschaften, 14, 1926
eg http://en.wikipedia.org/wiki/Tea_leaf_paradox

My gosh, we were doing this on the first floor of Felgar Hall at the University of Oklahoma in 1970 when I was a freshman in meteorology.

I don’t know how much this is costing them, but the Pet Tornado is available from Physlink.com for $4.95. “Shake the Pet Tornado clockwise and watch the mini tornado funnel form before your eyes” reads the accompanying copy. “Can you figure out why is it forming? What is the purpose of the fluid and what is the purpose of small particles in the tube?” I don’t know — but I’m sure a team of international scientists can work it out. “Amaze your friends with this amazing desk toy!”
Sounds like fun.

Ken Harvey

Tempest in a teacup? Take the cylinder walls away and you will have tea in your lap.
Change the speed of spin and perhaps you could eliminate the hurricanes. Help! Research money badly needed.

banjo

Milk and two sugars please.

CodeTech

At the risk of sounding too cynical, here’s how this works:
1. Determine that vortices are inadequately understood (a good thing)
2. Launch a research program to understand vortices (a good thing)
3. Finance program by pointing out that vortices are involved in hurricanes, tornadoes and other weather phenomena that are expected to get worse with AGW (a not-so-good thing)
4. Repeat grade-school level experiments which THIS poster performed in grade 6 (blue and red food coloring to show the swirls), claim they’re unexpected and nobody ever noticed before
5. Create a simplified model, sell model to ILM for use in CG used in movies and TV ads, recoup all research program costs
6. Integrate vortex models into Model E, watch in awe as the planet is obliterated by vortices within another few ppm of CO2
7. Exclaim that this is all worse than we thought, and if CO2 emissions don’t stop IMMEDIATELY the entire planet down to the 2 million degree molten core will be torn asunder by vortices. Create HighDef video demonstrating the destruction
8. Sell HighDef video as opening sequence in new climate porn blockbuster Hollywood movie. Earn enough for another home in the tropics. Beachside.
9. Have Vortex Theory and simplified model forcefully inserted into school textbooks, along with a few disclaimers about how most students will never reach adulthood because the Vortices will destroy the planet before then.
10. Determine that all Vortices, globally, are man-made, and before humans walked the Earth there was never a Vortex, ever. Nobody EVER found dinosaur trailer parks torn apart by a tornado, right?
11. When asked by a 7 year old, “aren’t those little winglets on the tips of airplanes because of Vortices?”, rant uncontrollably for hours about how NOBODY ever studied Vortices before you, and that’s all a plot by the Vortex Deniers, funded by Big Calm.
12. Go on anti-depressants after your private emails between you and the NASA guys who first studied Vortexes in the 50s are publicly released. IN spite of the fact that only 4 people downloaded them.
13. End up on late night TV discussing how your enemies in highly funded fossil fuel denier cabals managed to completely destroy you.
14. Found dead in fleabag hotel room in some town nobody ever heard of, a victim of the grand Vortex conspiracy.

banjo
The Hobbs End Martian

Dried Leaves!
Also a vital component of the Infinite Improbability Drive…

CodeTech says:
November 30, 2010 at 10:29 am
11. When asked by a 7 year old, “aren’t those little winglets on the tips of airplanes because of Vortices?”, rant uncontrollably for hours about how NOBODY ever studied Vortices before you, and that’s all a plot by the Vortex Deniers, funded by Big Calm.

Heh heh. “Big Calm.”

Paul Vaughan

Taught in Introductory Fluid Mechanics …but funding hooks necessary:
“Ahlers and his team discovered a new unexpected phenomenon that was not known before for turbulent flows like this. When spinning the container slowly enough, no vortices occurred at first. But, at a certain critical rotation speed, the flow structure changed. Vortices then occurred inside the flow and the warm fluid was transported faster from the bottom to the top than at lower rotation rates. “It is remarkable that this point exists,” Ahlers said. “You must rotate at a certain speed to get to this critical point.””

banjo

The Hobbs End Martian.
how improbable was that!
Tea Hee!!!

1DandyTroll

Here’s a trick I think those doctors in the making can perform to actually test their “new found” phenomenon.
Rotate yourselves around your own central vertical axis, slowly slowly, at first, then faster, faster and faster. And away you go. However, if you don’t attain lift off and go ballistic in five minutes, only stop at your own risk.
Much cheaper ‘an any kind of drugs and with about the same side effects–even the surreal surround sound laughter from the onlookers.

Brent Hargreaves

jack morrow said: November 30, 2010 at 9:39 am
“I’m sorry, but I seem to have lost faith in the scientific community as a whole.”
Jack, those of us who are dismayed at the Hockey Team’s perversion of science must resist the temptation to become hardened cynics. The seeds of Climatography’s* own destruction are already sown, and it’s only a matter of time before their half-baked predictions go the way of previous scientific fraud; collapses in ignominy. The pesky planet – and the pesky laws of physics it operates under – cares not that the AGW lobby army is hoping and praying and rooting for for a continuation of the 1975-1998 warm spell.
Our opponents like to claim that we sceptics are somehow anti-science. Nah. It’s BENT scientists we loathe, not the real ones.
*They don’t deserve the ‘ology’; they barely deserve an ‘ography’.

Claude Harvey

Press Release: “International Team of Scientists Study ‘Flushing Toilet Swirl”

John F. Hultquist

There may be some parallels with turbulent mountain streams that seem to be moving rapidly and the lower wider rivers as they approach the sea which are smoother and seem to be slower. Except higher is slower and lower is faster. Along the way there is friction with the bottom and sides, vortices, and other complicating factors.
Earth isn’t a cylinder – did anyone mention this – so maybe they could move to the space station and work with spheres.

Gaylon

Hey ‘CodeTech’,
That’s not cynical at all: it’s pragmatic foresight based on 20/20 hindsight. The sad part is, that as funny as it is, it’s probably not far off the mark. Good job! 🙂

TimC

Reminds me of the end of one fluid dynamics lecture a long while ago where we fetched up singing “irrotational, incompressible, two dimensional fluid flow” to our prof as we were getting bored with the lecture – it goes well to the Cwm Rhondda (“bread of heaven…”) tune. Would’ve thought they’d got it nailed down by now …

Pull My Finger

In related news, Dr. Ralph Wiggums, Spingfield U., concluded after a 2 year, $5 million dollar research study that indeed his “cat’s breath smells like cat food”.

Alberta Slim

CodeTech says:
November 30, 2010 at 10:29 am
At the risk of sounding too cynical, here’s how this works:……….
Very good.
I enjoyed that.

lgl

And if you change the rotation you don’t need any temperature difference at all.
http://einstein.atmos.colostate.edu/~mcnoldy/spintank/

Mike McMillan

That’s a vortex above the teacup, not a vortice.
Regards,
Mike
grammar n*zi

Vince Causey

I seem to recall that James Bond prefered his martinis a certain way – shaken, not stirred. The next movie will probably have him order his martini swirled, not shaken or stirred.

Andy J

I’m not for sure what is new here, but I suspect it’s the transition point that relates to formalisms in superconductivity. Changes in stability and their explanations are an important part of hydrodynamics and thermodynamics. I note that very little if anything gets into Phys Rev Letters that is not of high interest and novelty, albeit in fields of sometime limited interest.
The point is that immediate dismissal of someone’s work without understanding what has been done or its significance does not serve the skeptic community well. Some of the replies here have the character of knee-slapping yokels motivated by poking at anything that comes along. Besides there is nothing in the work that immediately relates to AGW pro or con, simply a simple observation, likely correct, that may have been missed, despite the simplicity of the system. Most good discoveries turn out to be simple and obvious when explained.

jorgekafkazar

So far, the great majority of the commenters in this thread are dismissing this article because haven’t a clue as to the actual science involved, possibly either because the press release is written for general readership or because they have insufficient background in science to see beyond the prose therein. I’ve met Guenter Ahlers and I can assure you that he has a first class intellect. I saw him give a paper at an SAACS conference in Redlands, CA. His paper was head and shoulders above anything else presented. I once interviewed for a job in Riverside. When I was told that the other candidate was Dr. Ahlers, I advised the interviewer to hire him if they possibly could.
Guenter Ahlers received his BA degree in chemistry from UC Riverside in 1958 and a PhD in physical chemistry from UC Berkely in 1963. In 1963 he became a Member of Technical Staff at Bell Laboratories in Murray Hill, NJ. There he worked on critical phenomena near the lambda point in liquid helium and near magnetic phase transition, and on superfluid hydrodynamics. In 1970 he began research on Rayleigh-Bénard convection in liquid helium that led to the experimental observation of chaos in a fluid-mechanical system. In 1979 Ahlers moved to UC Santa Barbara, where he studied pattern formation in convection and Taylor-vortex flow, and turbulent Rayleigh-Bénard convection. He and his co-workers published about 270 papers in the Journal of Fluid Mechanics, Physics of Fluids, Physical Review A, B, and E, Physical Review Letters, and elsewhere. Ahlers became a Fellow of the APS in 1971 and of the AAAS in 1990. He received the IUPAP Fritz London Memorial Award in low-temperature physics in 1978, the Alexander von Humboldt Senior US Scientist Award in 1989, and the APS fluid-dynamics prize in 2007. In 1998 he was a Guggenheim Fellow. He was elected to the National Academy of Sciences in 1982 and became a Fellow of the American Academy of Arts and Sciences in 2004.
See the paper at: http://physics.aps.org/articles/v2/74

David Walton

I really don’t understand the snark and jeers in the comments section about this example of basic investigative physics. Please explain and expound on why it is not valid and deserves ridicule.

Billy Liar

Google only finds the term ‘healing length’ in association with Bose condensate and liquid helium (ie superfluids).
Is it also room temperature concept?

DesertYote

Wow, I have never seen such a collection of lame half cocked and condescending comments on WUWT, as I am reading now. Obviously, no one bothered to find out what the researchers are reporting. sheeesh!

Billy Liar

lgl says:
November 30, 2010 at 12:29 pm
And if you change the rotation you don’t need any temperature difference at all.
http://einstein.atmos.colostate.edu/~mcnoldy/spintank/

That barotropic instability looks suspiciously like visual features on Jupiter.

Scott Covert

The same lead researcher ten years ago…
{Head stuck in a Gym toilet getting a “Swirly” by field hockey team member}
“I wonder why the water spins in a circle like that”.

Gotta buy some stock in Lava Lamps Inc!

David Walton says:
November 30, 2010 at 12:53 pm
I really don’t understand the snark and jeers in the comments section about this example of basic investigative physics. Please explain and expound on why it is not valid and deserves ridicule.

Well, there’s this, of course:

When spinning the container slowly enough, no vortices occurred at first. But, at a certain critical rotation speed, the flow structure changed. Vortices then occurred inside the flow and the warm fluid was transported faster from the bottom to the top than at lower rotation rates. “It is remarkable that this point exists,” Ahlers said. “You must rotate at a certain speed to get to this critical point.”

It’s hard to actually explain why there are such jeers at what is a grade three physics experiment. When you turn the cylinder slowly, you don’t get a vortex. When you spin it faster, you do. I mean, seriously? You can buy “tornado” toys that use this principle.
The funding that will go into this would be far better spent on science classes at the grade school level — not that they’d be doing “experiments” like this, however, since they’d be deemed too elementary.
One thing we do know — these guys are not smarter than a fifth grader.

Claude Harvey

Re: jorgekafkazar says:
November 30, 2010 at 12:49 pm
“I’ve met Guenter Ahlers and I can assure you that he has a first class intellect. ”
Toilet bowl swirl has long attracted “first class intellects”, beginning with plumbing legend, Sir Thomas Crapper.

1DandyTroll

@jorgekafkazar
‘So far, the great majority of the commenters in this thread are dismissing this article because haven’t a clue as to the actual science involved, possibly either because the press release is written for general readership or because they have insufficient background in science to see beyond the prose therein. I’ve met Guenter Ahlers and I can assure you that he has a first class intellect. I saw him give a paper at an SAACS conference in Redlands, CA. His paper was head and shoulders above anything else presented. I once interviewed for a job in Riverside. When I was told that the other candidate was Dr. Ahlers, I advised the interviewer to hire him if they possibly could.’
So essentially you fire all cannons trying to sink everyone by trying to impress a bunch of skeptics with the bestest of strategy by appealing to authority or as google apparently would have it, argumentum asinum oscula. :p

Paul Bahlin

Sorry! Coriolis effect does not work at these scales.

pat

Dr. Ahlers might add the sun to his targeted swirling bodies. It appears to respond similarly, but its descent from patterned swirling to chaos is ill understood. But the recurrence to pattern along with the periodic nature of sunspot might make for an interesting subject to gain further knowledge.

Gilbert K. Arnold

@ Peter Walsh:
Peter Walsh says:
November 30, 2010 at 9:24 am
Quote from start of article
“The earth’s atmosphere and its molten outer core have one thing in common:”
Maybe Inner Core???
Peter, the reason they specifically mentioned the “outer core” as being molten is because from seismic data, we know that S(hear)-waves do not pass through liquids or molten material. Seismic ray paths that pass through the outer core show no S-wave component.

Gilbert K. Arnold

Peter Walsh says:
November 30, 2010 at 9:24 am
Quote from start of article
“The earth’s atmosphere and its molten outer core have one thing in common:”
Maybe Inner Core???
Peter
Peter: The reason the authors specifically mentioned the “outer core” as being molten is because we know that S(hear)-waves do not pass through molten or liquid substances. Seismic waves that pass through the outer core and reflect off the inner core and are recorded at the surface show no S-wave component. Therefore the conclusion is that the outer core is molten or a liquid.

Gilbert K. Arnold

@ Peter Walsh:
Peter Walsh says:
November 30, 2010 at 9:24 am
Quote from start of article
“The earth’s atmosphere and its molten outer core have one thing in
in common”
Maybe Inner Core???
Peter, the reason they specifically mentioned the “outer core” as being molten is because from seismic data, we know that S(hear)-waves do not pass through liquids or molten material. Seismic ray paths that pass through the outer core show no S-wave component.

phlogiston

This is not the Coriolis effect, that is linear, this is nonlinear. A classic Hopf bifurcation laminar-turbulent transition. With increasing rotation speed the system is gradually driven away from equilibrium. At a certain disequilibrium point, nonlinear pattern formation breaks out. The increase in warm fluid transport at the critical transition point could possibly tie in with (and give support to) Willis’ Constructal Law (systems converge to maximise flow of something) despite the hard time his theory was given on a recent thread here. The “boundary forcing” referred to is well known in for instance Rayleigh-Benard pattern formation convection in liquid helium.

H.R.

Andy J says:
November 30, 2010 at 12:39 pm
jorgekafkazar says:
November 30, 2010 at 12:49 pm
David Walton says:
November 30, 2010 at 12:53 pm
===================================
Thanks for pointing out that many of the points being made are not on point, which brings me to my point ;o)
I wasn’t quite sure what to make of this post because it seems so simple – I too had to do some swirly experiments back in the day – and yet there seemed to be something I was missing. I usually like to make a giggler comment on a post like this but something kept niggling at the back of by brain.
I’ve been checking in on the comments from time to time and each time I come back, I keep scrunching up my eyes and trying to visualize the boundries of a vortex before and after it forms to where we can see it. I intend to check back a few more times until hopefully, I “get it.”
Anyhow, your comments were the “tipping point” (fair use of that, eh?) to keep on pondering instead of posting something about funding creamer swirls in coffee.

lgl

Billy Liar
Yet still they wonder why.

CodeTech

Tell you what… for those 2 people in the entire world who think my post was mocking the study of vortices, check the first two points… they both say “(a good thing)”.
It is truly unfortunate that with the state of Science lately, the remaining 12 points of my post would be unsurprising, if they were to occur.
In fact, the study of vortices is serious business, and has innumerable real-world benefits (including those winglets I mentioned, they actually reduce fuel use or increase aircraft range, depending on your perspective).
Further understanding of physical processes is always a good thing. Personally, I love study of real-world, and while I’m fine with models I think we’ve all seen the “worst case” scenario of simplified model usage taken to ridiculous extremes.

George E. Smith

Well I didn’t see that they said anywhere that they have yet discovered that when you flush the toilet in the southern hemisphere, that it rotates, in the opposite direction from the northern hemisphere.
I can see the need for a research grant to examine toilet flushings from pole to pole to find out what the blazes happens at the equatorial regions, when the flush stops goping one way, and starts going the other way. Perhaps that’s why they don’t have flush toilets in some parts of Africa; because the things simply will not rotate in either direction.