CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

Kolmogorov scale .... LES

Register Blogs Community New Posts Updated Threads Search

Like Tree3Likes
  • 1 Post By LESer
  • 1 Post By FMDenaro
  • 1 Post By FMDenaro

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 8, 2005, 09:45
Default Kolmogorov scale .... LES
  #1
LESer
Guest
 
Posts: n/a
Hello,

I am doing some LES of a reacting flow and I need to calculate some values. How can I calculate the Kolmogorov timescale and the Kolmogorov Reynolds Number? Also how can I calculate the dissipation rate (epsilon)?

Thanking you all.
maphd likes this.
  Reply With Quote

Old   August 12, 2005, 01:01
Default Re: Kolmogorov scale .... LES
  #2
yuan
Guest
 
Posts: n/a
I guess you need read a textbook. Select large scales, estimate the dissipation scales by using the Komogorov relations and then estimate epsilon.
  Reply With Quote

Old   July 2, 2015, 20:48
Default
  #3
Member
 
Join Date: May 2013
Posts: 32
Rep Power: 13
maphd is on a distinguished road
Hello LESer,
Did you find how to calculate kolmogorov length scale in LES? I really appreciate if you could give me some help on this.
Thanks,
maphd is offline   Reply With Quote

Old   July 3, 2015, 04:38
Default
  #4
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 6,882
Rep Power: 73
FMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura about
there is no Kolmogorov scale in LES ! the smallest scale is defined by the filter lenght, not by the molecular viscosity and lies in the inertial subrange.
maphd likes this.
FMDenaro is offline   Reply With Quote

Old   July 3, 2015, 06:36
Default
  #5
Member
 
Join Date: May 2013
Posts: 32
Rep Power: 13
maphd is on a distinguished road
FMDenaro thank you very much for your reply. Can you tell me a way to calculate this smallest length scale? I just need a way to calculate something similar to kolmogorov length scale? Can I write a user defined function for kolmogorov length scale maybe? If you could give me some help on this I really appreciate it.
Thank you very much
maphd is offline   Reply With Quote

Old   July 3, 2015, 06:54
Default
  #6
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 6,882
Rep Power: 73
FMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura about
Kolmogorov scale is dictated by the physics of the problem.
LES provides the smallest scale at about twice grid step size. That has nothing to do with kolmogorov scale
maphd likes this.
FMDenaro is offline   Reply With Quote

Old   July 3, 2015, 07:01
Default
  #7
Member
 
Join Date: May 2013
Posts: 32
Rep Power: 13
maphd is on a distinguished road
FMDenaro, thank you very much for your reply. Is there any way I can calculate and see that smallest scale in Fluent? I really appreciate your help. I just need to calculate something corresponding to kolmogorov length scale in LES. Thanks a lot.
maphd is offline   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
Kolmogorov turbulence time scale iko FLUENT 2 July 15, 2008 11:04
LES inlet length scale f.neilson Main CFD Forum 0 January 31, 2005 14:26
Length scale separation in LES Ray Main CFD Forum 1 June 7, 2002 09:50
Kolmogorov scale T.Misawa Main CFD Forum 2 December 12, 2001 05:02
Kolmogorov scale of atmospheric BL J. Kim Main CFD Forum 0 December 8, 2000 12:45


All times are GMT -4. The time now is 18:33.