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#1 |
Guest
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Hi,
I would like to know if a laminar flow (not potential flow), has got the turbulent or eddy viscosity? If the answer is yes, in which way I can compute it? Thank you Mike |
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#2 |
Guest
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No. By definition a laminar flow has no turbulence. Eddy viscosity is a model for how turbulence works, and is computed using turbulence models, developed to simulate turbulent flows.
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#3 |
Guest
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Thank you!
Another question: is the eddy viscosity proportional with an another (non turbulent) quantity? I.e., the kinematic viscosity? |
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#4 |
Guest
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Have a look at pages 6-7 of the following link.
ftp://ftp.nist.gov/pub/bfrl/mcgratta...S/techman3.pdf I am sure this can help you. Steve |
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#5 |
New Member
Santhosh
Join Date: Oct 2009
Posts: 14
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Steve,
th link given by you is nt working anymore. Can you post an updated one. |
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#6 |
Senior Member
Join Date: Jul 2009
Posts: 345
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You do realize that the thread you resurrected is 7 years old, and Steve may not inhabit these fora anymore, don't you?
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#7 | |
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Sydney Miles TEKAM
Join Date: Apr 2010
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Quote:
Kinematic viscosity is a property of the flui. It remains constant in every area of most common flow. |
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#8 |
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Santhosh
Join Date: Oct 2009
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ooops..
I didnt realize, I thought the qn was still relevant today..! |
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#9 |
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Patrick Godon
Join Date: Apr 2010
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Eventhough the original post is 7 years old... I thought maybe someone might still be interested in that topics.. or for all others who might be interested... In a turbulent flow the size of the Eddies L can be as large as the size of the domain and the velocity of the eddies is as large as the change in the velocity over a distance L, so Vturb ~ V(x+L)-V(x) , such that the viscosity of the turubulence can be written
viscosity from tubulence ~ Vturb L Usually supersonic eddies dissipate quickly by shocks such that Vturb < Vsound . In the limit of small L, one can write Vturb = V(x+L)-V(x) = (dV/dx) L such that turbulent viscosity ~ L^2 (dV/dx) the turbulent viscosiity is proportional to the shear dV/dx |
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