CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

LRN turbulence models in Fluent

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 4, 2000, 08:19
Default LRN turbulence models in Fluent
  #1
Luo Shengping
Guest
 
Posts: n/a
Hello,

Is there anyone who knows how the LRN(low-Reynolds number) turbulence models were implemented in Fluent? How can we check the grids in the near wall region: like with the two-layer zonal model to check y+ =1 or....? Thank you for your feekback!

Cheers,

Shengping LUO
  Reply With Quote

Old   December 5, 2000, 11:07
Default Re: LRN turbulence models in Fluent
  #2
dory
Guest
 
Posts: n/a
PARA IMPLEMENTAR ESTE MODELODEBES EN PANTALLA ESCRIBIR LO SIGUIENTE: DEFINE/MODELS/VISCOUS/LOW-RE-KE

LUEGO, LA TECLA 'ENTER' Y PODRAS COLOCAR EL MODELO DE BAJO REYNOLDS QUE DESEES, FLUENT POSEE CERCA DE 5 MODELOS DISTINTOS, IR A ESTA PAGINA PARA CONOCERLOS:

HTTP://WWW.CAEWISC.EDU/MANUALS/FLUENT5.2/FLUENT5
  Reply With Quote

Old   December 6, 2000, 03:56
Default Re: LRN turbulence models in Fluent
  #3
Luo Shengping
Guest
 
Posts: n/a
Hi,

Thank you for your reply, but I cannot understand what you write: it's in which language? On the other hand, I can't visit the site you gave me: I was told the site "does not have a DNS entry". Could you check if there is an error in the address of the site? Much thanx!

Shengping
  Reply With Quote

Old   December 6, 2000, 07:55
Default Re: LRN turbulence models in Fluent
  #4
dory
Guest
 
Posts: n/a
sorry, I write in spanish, but now it will try to explain in english.

IN ORDER TO IMPLEMENT THIS MODEL YOU MUST IN SCREEN WRITE THE FOLLOWING THING: DEFINE/MODELS/VISCOUS/LOW-RE-KE SOON, KEY ' ENTER' AND PODRAS TO PLACE THE MODEL OF LOW REYNOLDS WHO YOU WISH, FLUENT HAS NEAR 5 DIFFERENT MODELS.

it will send to your direction the file to you so that it you read

  Reply With Quote

Old   December 6, 2000, 09:39
Default Re: LRN turbulence models in Fluent
  #5
Luo Shengping
Guest
 
Posts: n/a
Hi Dory,

Thank you again for your quick response: this is what I have done. My problem is: how to check the mesh dependence(or independence)? They just say that you should have very fine mesh near wall, but how fine of the mesh is enough? With two layer model they give you a criteria Y+=1 (or Y+=4~5), but with LRN, I cannot find any information for what I should check. The above method you described can just be found in the release note. Do you have any suggestions with LRN in Fluent? Thanx!

Regards,

Shengping
  Reply With Quote

Old   December 22, 2000, 10:45
Default Re: LRN turbulence models in Fluent
  #6
Frédéric Launoy
Guest
 
Posts: n/a
Hi Luo,

You're right. For the LRN, the criterium for the y+ is the same as for the 2-layer model, that is to say, theoritically you should try to have y+=1. In any case, the value should not exceed 5.

Best regards, merry Christmas and good luck (the convergence is hard to get with LRN)

Fred
  Reply With Quote

Old   December 22, 2000, 10:59
Default Re: LRN turbulence models in Fluent
  #7
Luo Shengping
Guest
 
Posts: n/a
Hi Frédéric,

Merry Christmas and Happy New Year to you too. Yesterday Dr. Kim of Fluent Co. confirmed me as you have said, but thank you for your kind reply just the same. Hope the solution will be converged!

Regards,

Shengping
  Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Implementing low Re number k-e models in Fluent. kiran FLUENT 1 July 3, 2017 18:04
Accuracy of Boundary Layers With Turbulence Models de5truction FLUENT 2 June 3, 2011 19:36
Additional turbulence models for FLUENT Travis FLUENT 0 December 19, 2008 12:58
Y+ ranges for Turbulence models han toss Main CFD Forum 2 October 16, 2005 05:07


All times are GMT -4. The time now is 21:02.