|
[Sponsors] |
March 24, 2003, 09:45 |
Turbulent viscosity in Laminar Flow
|
#1 |
Guest
Posts: n/a
|
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 |
|
March 24, 2003, 09:52 |
Re: Turbulent viscosity in Laminar Flow
|
#2 |
Guest
Posts: n/a
|
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.
|
|
March 24, 2003, 09:57 |
Re: Turbulent viscosity in Laminar Flow
|
#3 |
Guest
Posts: n/a
|
Thank you!
Another question: is the eddy viscosity proportional with an another (non turbulent) quantity? I.e., the kinematic viscosity? |
|
March 24, 2003, 10:40 |
Re: Turbulent viscosity in Laminar Flow
|
#4 |
Guest
Posts: n/a
|
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 |
|
April 10, 2010, 18:48 |
|
#5 |
New Member
Santhosh
Join Date: Oct 2009
Posts: 14
Rep Power: 17 |
Steve,
th link given by you is nt working anymore. Can you post an updated one. |
|
April 12, 2010, 09:56 |
|
#6 |
Senior Member
Join Date: Jul 2009
Posts: 358
Rep Power: 19 |
You do realize that the thread you resurrected is 7 years old, and Steve may not inhabit these fora anymore, don't you?
|
|
April 12, 2010, 10:04 |
|
#7 | |
New Member
Sydney Miles TEKAM
Join Date: Apr 2010
Posts: 7
Rep Power: 16 |
Quote:
Kinematic viscosity is a property of the flui. It remains constant in every area of most common flow. |
||
April 12, 2010, 10:21 |
|
#8 |
New Member
Santhosh
Join Date: Oct 2009
Posts: 14
Rep Power: 17 |
ooops..
I didnt realize, I thought the qn was still relevant today..! |
|
April 12, 2010, 12:40 |
turbulent flows
|
#9 |
New Member
Patrick Godon
Join Date: Apr 2010
Posts: 19
Rep Power: 17 |
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 |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
reversed flow at pressure inlet and turbulent viscosity is limited.... | cfdiscool | FLUENT | 10 | June 10, 2015 07:15 |
Using a turbulent model when the flow is entirely laminar. | mwhyte | FLUENT | 1 | June 7, 2012 11:35 |
flow with high turbulent viscosity ratio | Phillips | Main CFD Forum | 2 | August 25, 2008 19:01 |
laminar and turbulent flow over a single airfoil. | Pablo Cornejo | FLUENT | 0 | August 30, 2005 18:57 |
Reynolds and Turbulent Flow | Frederic Dubinski | Main CFD Forum | 2 | October 20, 2004 14:57 |