Thanks BenLurkin.
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Posted on 05/28/2019 11:36:46 AM PDT by BenLurkin
For decades, physicists, engineers and mathematicians have failed to explain a remarkable phenomenon in fluid mechanics: the natural tendency of turbulence in fluids to move from disordered chaos to perfectly parallel patterns of oblique turbulent bands. This transition from a state of chaotic turbulence to a highly structured pattern was observed by many scientists, but never understood.
For decades, physicists, engineers and mathematicians have failed to explain a remarkable phenomenon in fluid mechanics: the natural tendency of turbulence in fluids to move from disordered chaos to perfectly parallel patterns of oblique turbulent bands. This transition from a state of chaotic turbulence to a highly structured pattern was observed by many scientists, but never understood.
The researchers combined...dynamical systems theory, with existing theories on pattern formation in fluids and advanced numerical simulations. They calculated specific equilibrium solutions for each step of the process, enabling them to explain the transition from the chaotic to the structured state.
In fluid mechanics, stripe pattern formation is important because it shows how turbulent and laminar flows are in constant competition with each other to determine the final state of the fluid, i.e., turbulent or laminar. This competition arises whenever turbulence forms, such as when air flows over a car. The turbulence starts in a small area on the car's roof, but then it spreads—because turbulence is stronger than laminar flow in this particular case. The final state is therefore turbulent.
When the stripe pattern forms, it means that the laminar and turbulent flows are equal in strength.
(Excerpt) Read more at phys.org ...
Thanks BenLurkin.
I don’t want an enigma anywhere near my crack, no sir.
A little more information about this part of the article might be helpful. This is like saying, "We found the cure for cancer." It leaves people asking, "Well, what is it?"
Which was first, the chicken or the egg... that’s the real question!
The Hole thing was figured out thanks to observations of Uranus.
Exact invariant solution reveals the origin of self-organized oblique turbulent-laminar stripes.
Good. Now I’ll be able to sleep at night.
Thank you! My brain is hurting after reading that.
I would but...entropy just isn't what it used to be.
Thank you. Scanned it. Will read at leisure later.
We were just talking about that the other day.
The one thing I found interesting about it is that all of the code and input files are available to download, if you want to replicate the data. Not for the faint of heart, and only for Linux, as far as I can tell.
They're not afraid of somebody checking their work. Didn't notice that it's Linux only … fodder for my ubuntu machine, if I go that route.
BTW, ".ch" domain is Switzerland, not China. If you didn't know that.
I take that back. Looking through the settings, you can compile on Windows.
Bttt
The hide of the Bottlenose Dolphin (Tursiops truncatus) produces laminar flow.
The airfoil of the North American P-51 Mustang produces laminar flow.
Both result in reduced drag and higher speed.
Which would be faster if the Dolphin had a P-51 engine?
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