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

Dns

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   June 6, 2012, 06:51
Lightbulb Dns
  #1
New Member
 
Anonymous
Join Date: Jun 2009
Posts: 18
Rep Power: 8
vinerm is on a distinguished road
Hello

This discussion is about DNS and is not pertaining to any particular tool.

Usually, DNS is carried out in spectral space, especially when it comes to homogeneous turbulence. However, I would like to have your opinion about the "Implications that could arise out of carrying out DNS in physical space".

Regards,
Vinerm Andrews
vinerm is offline   Reply With Quote

Old   June 6, 2012, 07:21
Default
  #2
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 1,651
Rep Power: 23
FMDenaro will become famous soon enough
Quote:
Originally Posted by vinerm View Post
Hello

This discussion is about DNS and is not pertaining to any particular tool.

Usually, DNS is carried out in spectral space, especially when it comes to homogeneous turbulence. However, I would like to have your opinion about the "Implications that could arise out of carrying out DNS in physical space".

Regards,
Vinerm Andrews
no implication at all ... Assuming that DNS means that you must solve for all the characteristic flow scales, you can use SM, FD, FV, FEM ....
FMDenaro is offline   Reply With Quote

Old   June 6, 2012, 14:30
Default
  #3
Senior Member
 
cfdnewbie
Join Date: Mar 2010
Posts: 551
Rep Power: 11
cfdnewbie is on a distinguished road
Quote:
Originally Posted by vinerm View Post
Hello

This discussion is about DNS and is not pertaining to any particular tool.

Usually, DNS is carried out in spectral space, especially when it comes to homogeneous turbulence. However, I would like to have your opinion about the "Implications that could arise out of carrying out DNS in physical space".

Regards,
Vinerm Andrews

As long as you can guarantee that you are doing a real DNS with all scales resolved, there's no difference at all. Just note that with non-spectral methods you will probably need more DOF to be numerics-free than with a spectral approach!
cfdnewbie is offline   Reply With Quote

Old   June 6, 2012, 16:09
Default
  #4
Senior Member
 
sbaffini's Avatar
 
Paolo Lampitella
Join Date: Mar 2009
Location: Italy
Posts: 534
Blog Entries: 14
Rep Power: 17
sbaffini will become famous soon enough
DNS in pipes is most commonly (assumed to be) done with second order spatial schemes.
sbaffini is offline   Reply With Quote

Old   June 6, 2012, 16:55
Default
  #5
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 1,651
Rep Power: 23
FMDenaro will become famous soon enough
just to add that DNS performed in physical space is practically the only way to face non-simple geometry
FMDenaro is offline   Reply With Quote

Old   June 10, 2012, 03:47
Default Homogeneous and Non-homogeneous
  #6
New Member
 
Anonymous
Join Date: Jun 2009
Posts: 18
Rep Power: 8
vinerm is on a distinguished road
Hello Everyone

Thank you all for your replies. As far as I have been able to resolve by studying papers and books, spectral methods have issue in resolving non-homogeneous turbulence but whether geometry is complex or not does not really matter. However, I am still not even a beginner with DNS. I have just read a few papers about it. So, thank you all.

Regards,
Vinerm Andrews
vinerm is offline   Reply With Quote

Reply

Tags
dns, turbulence

Thread Tools
Display Modes

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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Everything you need to compute DNS in channel vs OF 2.1.0 levka OpenFOAM Running, Solving & CFD 25 July 6, 2015 16:46
DNS in Turbulent S.O.S. Urgent Hengky FLUENT 11 September 28, 2006 10:07
what is DNS ? Phillip Main CFD Forum 10 August 28, 2003 15:28
Complicated Homogeneous Shear DNS ff_fan Main CFD Forum 0 December 9, 2002 19:23
DNS of homogeneous shear flow: comments please! ff_fan Main CFD Forum 1 September 12, 2002 02:28


All times are GMT -4. The time now is 15:20.