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

doubt about DNS ressolution

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 28, 2005, 08:49
Default doubt about DNS ressolution
  #1
han
Guest
 
Posts: n/a
Hi all, i got one big doubt,i got DNS of 3D diffussion flame, to check whether my grid ressoulution is sufficient enough or not.. i want to do simple technique like calculating of total production equal to dissipation, am i right , if not please let me know why it is not right? if all scales is ressolved in my DNS, then total production will be equal to total dissipation other wise not.. please respond ur views on this , i am very much eagerly interested to know more about this..

  Reply With Quote

Old   September 28, 2005, 11:43
Default Re: doubt about DNS ressolution
  #2
tom
Guest
 
Posts: n/a
What do you mean? The local production-dissipation of the global (for the whole domain)? There is no balance production- dissipation for the whole domain if you simulate a jet. Look at the transport equation for the mean kinetic energy: advection of K out of the domain = prod - diss integrated over your domain on average. In other words, not all kin. energy is dissipated in the domain because a part is advected out the domain.

/Tom
  Reply With Quote

Old   September 29, 2005, 02:26
Default Re: doubt about DNS ressolution
  #3
han
Guest
 
Posts: n/a
Hi Tom,

I am talking about global average production equal to dissipation.i want to calculatig of total production -dissipation, based on the transport equation of mixture fraction variance(being my DNS is non-premixed combustion).. please let me know
  Reply With Quote

Old   September 29, 2005, 02:40
Default Re: doubt about DNS ressolution
  #4
han
Guest
 
Posts: n/a
Hi Tom , For entire domain i want to calculate total production(2*rho*u_i''*z''*dho_z/dho_x)(production term in mixture fraction variance transport equation) equal to total dissipation(2*rho*D*(dho_z''/dho_x)**2).

all these terms are in average scence (in RANS context). i would like to know whether both the terms are equal or not? thankyou in advance

  Reply With Quote

Reply

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
doubt about DNS and LES of combustion chinthakindi Main CFD Forum 5 August 17, 2013 11:56
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
I am suspecious about DNS kenn Main CFD Forum 1 March 4, 2003 07:21
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 05:57.