Pictures of Turbulence
On the earth, most fluids are, at most times, turbulent. There are many research groups around the world who are working on turbulence in various different physical (and astrophysical) contexts. Links to some of these groups are available near the bottom of my home page.
Below is a selection of pictures of turbulence in various places.
1. Turbulence in Art
Whirlpools (vortices) in the woodblock prints by Hiroshige Utagawa: `Vortices in the Konaruto stream' and ?.
A woodcut print by Katsushika Hokusai, `The Great Wave Off Kanagawa':
Van Gogh's `Starry Night', with the turbulent air made `visible':
2. Turbulence in Nature
There are many cool pictures (and explanations) at the GalleryOfFluidMechanics.com web site. It's sister site www.fluidmechanics.net has lots of pictures and straightforward explanations too.
Clouds, winds, storms, atmosphere, rivers, oceans.
Some shots of clouds showing the development of the Kelvin-Helmholtz (KH) instability. This instability can occur when two distinct layers of a fluid are in relative motion. For example, the top layer flowing faster than the bottom layer (from right to left in the above shots). The interface between the layers develops `wiggles' or rolls which can evolve into vortices. This instability in the interface means that the two layers start to mix, and can lead to fully developed turbulence in either layer. See the Wikipedia entry (for example) for more details. There are more photos like these at the Cloud Appreciations Society website.
Twin typhoons (aka hurricanes) in the Pacific ocean. This is a satellite picture taken on 30 June 2004.
Note the anti-clockwise (right-handed) sense of their rotation. In the southern hemisphere hurricanes rotate in the opposite sense. Hurricanes are typically about 1000km across and have wind speeds of over 200 km/hr. They result from the interaction of the earth's rotation (the Coriolis force, hence the different sense of rotation in each hemisphere) and ...
When this picture was taken, the typhoon on the left ("Mindulle") had a maximum wind speed of 200 km/hr.
The vortices shed from the trailing edges of wings are clearly visible in the clouds through which this aeroplane is flying. See this link for more details.
Smoke from a burning match helps makes vortices in the air nearby stand out. The vortices may be due to the air above the match being heated and rising through the still surrounding air. At the interface between these two pieces of air there is shear and the Kelvin-Helmholtz instability can occur (see above).
Pictures and explanations of shock waves caused by (for example) planes flying faster than the speed of sound can be found at www.kettering.edu/~drussell/Demos.
Vortices in geology (yes, in rocks!).
Well actually, vortices in the ocean sediment that got turned into rocks. This is a picture of so-called "flame structure" in (mass emplaced) sedimentary rocks. Above the hand, you can see a wavy layer similar to a Kelvin-Helmholtz instability pattern. When a mixture of water and silt/sand/... flows down a continental shelf, its bottom boundary can form a shear layer with the sediment already sitting on the sea floor. Boundary layer instabilities can then lead to the generation of vortices. These can get `frozen' into the sediment as it settles out and eventually solidifies into rock. (Courtesy, Adam Vonk)
3. Turbulence in Space
Turbulence in space is a little different from that on earth since
it often involves a plasma
[a gas which is hot enough that the atoms have been ionised into electrons and ions],
rather than the more familiar electrically neutral fluids like water and air. This is my main research interest and you can find details about turbulence in such conducting fluids at my research interests webpage.
As Homer Simpson despondently said,
"Oh, there's so much I don't know about astrophysics. I wish I'd read that book by that wheelchair guy."
["Treehouse of Horror VI" episode , 1990. See the script for this episode and the simpsonsmath.com website].
Pictures of space are, naturally, a little harder to obtain However, there is lots of scientific data available from telescopes---including the Hubble space telescope---and spacecraft (eg, Pioneer, Voyager, Yohkoh, SOHO, Ulyssess, WIND, TRACE). Some of these spacecraft, like TRACE which looks at the atmosphere of the sun, orbit the earth and can produce movies. Others like Ulyssess and the Voyagers are travelling through the solar system and measure things like the speed of particles in space and the magnetic field there.
Here's an example of spiral galaxies colliding, taken by Debra Meloy Elmegreen using the Hubble Space Telescope. See the Astronomy Picture of the Day archive for the credit for this photo, plus a description of what's happening (and a bigger version).
There's another galaxy collision at the same site (again from Hubble) , with a thumbnail shown here:
There are also artists sketches of the physics occuring out there, usually not to scale (since that's not the point).
Here's one of the Solar Wind and the Earth's Protective Magnetic Shield.
It shows the solar wind heading into space and impacting Earth's
protective magnetic shield, its magnetosphere. The particles are seen
heading out in all directions, but with some of them hitting our
magnetosphere. Earth's magnetic field lines are shown in concentric
purple ovals, pushed on by pressure from the Sun and elongated on the
side facing sway from the Sun. If the solar wind is particularly
strong or if a solar storm impacts us, their energy can be transferred
down to Earth via our magnetic field lines and cause power,
communication, and navigation problems.
(Taken from the SOHO website).
You can see some pictures of waves in space (including shock waves) at the GalleryOfFluidMechanics.com web site.
Turbulence plays important roles throughout the lifetime of a star. Giant turbulent clouds of gas [~... kilo-parsecs or ...km across] collapse under the force of gravity to form stars. The interiors and atmospheres of many types of stars are turbulent. And the "winds" which the atmospheres turn into are turbulent too.
4. Turbulence Experiments
Once a year, the journal "Physics of Fluids" publishes a selection of pictures from experiments, observations, and computer simulations. A few of these are shown here. Many, many more are available at the Physics of Fluids "Gallery of Fluid Motion" website.
This page is under construction. Suggestions and attributions for the pictures are welcomed.
Last modified May 2008.
Sean Oughton.
Mathematics Department, University of Waikato, New Zealand.