Sunday, November 01, 2015

Making Waves


A day or so ago, an amazing picture of a Kelvin-Helmholtz instability backlit by the sun has appeared in many places.  The one shown below is from the bleealuna's imgur site


These patterns are formed when there is a velocity difference at the interface between fluids introducing a shearing force.

Now this is all over the net, but a Eli's Feedly feed had another picture which is eerily similar (it is the day after Halloween) but on a vastly different scale.  The Impact Manufacturing lab at Ohio State has been developing new methods of impact welding where two sheets of metal are forced into each other by creating an electrical or laser ablated plasm below them


Did somebunny say Kelvin Helmholtz Waves?


The figure is about 1 mm across.  The picture of the Kelvin-Helmhotz waves in the atmosphere at least a few km.  What is a difference of 106 for a good model.

For more information there are videos at Ohio State.  


7 comments:

  1. Brings back some long ago memories (good memories) of when I was doing physical models of discrete two layered stratified flows.

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  2. We were in Breck during this general wx pattern. If I had seen that, I'd have used all the memory on my phone taking pix...

    Best,

    D

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  3. I don't know if this first print of Hokusai's is relevant, but it looks good...

    https://en.wikipedia.org/wiki/Thirty-six_Views_of_Mount_Fuji

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  4. Eli gives himself too little credit: in viscosity terms it's more like fifteen orders of magnitude

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  5. This is a very good point as fundamental physics scales. Just because a phenomena is large scale does not mean it suddenly doesn't follow physics or that complexity considerations increase in importance.

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