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-   -   Low Reynolds number k-E Turbulent Model (http://www.cfd-online.com/Forums/fluent/29966-low-reynolds-number-k-e-turbulent-model.html)

Sohail July 2, 2002 07:12

Low Reynolds number k-E Turbulent Model
 
Hello,

Can any body please help me how to model low reynolds number K-E Turbulent Model in Fluent because the defalt K-E Turbulent Model used by Fluent is not valid for Low raynolds number flow. Thanks for your valuable suggestion

lax July 2, 2002 12:37

Re: Low Reynolds number k-E Turbulent Model
 
I am having same question in my mind. Can you just tell me, Re number u are having in your problem.


Steve July 2, 2002 17:03

Re: Low Reynolds number k-E Turbulent Model
 
A Low Reynolds number model is a turbulence model that integrates through the viscous sub-layer down to the wall (i.e. the locally low Reynolds number region of the flow). It is still only applicable to high Reynolds number flows where the flow is fully turbulent. It is not a model for solving flows with low global Reynolds number. For that you need a transition model and I don't think that a good universal transition model exists.

Greg Perkins July 2, 2002 23:37

Re: Low Reynolds number k-E Turbulent Model
 
There is the low Re model in Fluent. Activate it through the text interface at:

/define/models/viscous/turbulence-expert low-re-ke yes

Greg

Karl July 3, 2002 02:45

Re: Low Reynolds number k-E Turbulent Model
 
There are six models available through text command:

define/models/viscous/low-re-ke-index

Index: 0...Abid

1...Lam-Bremhorst

2...Launder-Sharma

3...Yang-Shih

4...Abe-Kondoh-Nagano

5...Chang-Hsieh-Chen

Fluent uses number 3 as default.

gmwsy August 9, 2009 14:30

Low Re
 
Quote:

Originally Posted by Greg Perkins
;101560
There is the low Re model in Fluent. Activate it through the text interface at:

/define/models/viscous/turbulence-expert low-re-ke yes

Greg

Hi~ Greg:

Very good information. Thank you!

But it seems that the range of low Re has never been mentioned in the Fluent mannual. Do you know what range of Re can be classified into low Re in Fluent?
Thanks a lot.

shg74 February 2, 2010 12:01

Hi Greg,

I tried several times the text command, but gives me "invalid command". Can you help me?

atturh July 26, 2011 15:11

greg's command
 
/define/models/viscous/turbulence-expert/low-re-ke yes

there is a "/" between turbulence-expert and low-re-ke yes.

this should get u to the command

shg74 July 27, 2011 03:30

Thanks
 
It works but just for one of the mentioned turbulence models

sona December 13, 2011 06:08

Hi Greg

Really good information.Thanks alot.
Is Lai and So model also available in Fluent?...

kbaker December 16, 2011 04:34

before you select low RE k-e model from text command you need first to choose standard k-e from the menu define>model> viscus else you cannot see the low RE k-e model in text command.

sona December 16, 2011 09:00

Hi Kbaker

Thanks for your reply.


I tried the following command after selecting define/models/viscous/k-epsilon standard,

/define/models/viscous/turbulence-expert> low-re-ke
Enable the low-Re k-epsilon turbulence model? [yes] yes

/define/models/viscous/turbulence-expert> low-re-ke-index

but it is not showing the available Low Re models.
Hope you can help me.

samcfd January 7, 2013 02:01

There are six models available through text command:

define/models/viscous/low-re-ke-index

Index: 0...Abid

1...Lam-Bremhorst

2...Launder-Sharma

3...Yang-Shih

4...Abe-Kondoh-Nagano

5...Chang-Hsieh-Chen

Fluent uses number 3 as default.


I was given in one of the posts that the above low re k-e models are available in FLUENT. Can someone pls from where these models came from. WHich book or material describes its significance in FLUENT

vincenzo December 3, 2013 12:59

Hello everyone. Can anybody point me how to turn on the low-re-ke turbulence model in Fluent 14?

In the text user interface there is no such position in /define/models/viscous/turbulence-expert. If I enter 'help' there is a note that says: "These followed by "*" are currently disabled" and below there is among others low-re-ke followed by "*".

How to turn it on? Is it possible? Thanks.

Mohamed Refaat December 21, 2015 19:05

I'm trying to improve my simulation using non-linear turbulence models such as the modified k-epsilon model of craft et al. 1996

Please, is there nonlinear turbulence models built in fluent that can be activated using the same manner as low Re model?

Thanks in advance


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