CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Courant Number

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

LinkBack Thread Tools Display Modes
Old   April 28, 2003, 15:22
Default Courant Number
Parshant Dhand
Posts: n/a
HI there, i am modeling turbulent flow in a cylinder, my problem is that while solving the solution converges if i reduce the courant number to say 0.001, but this does not predict the actual physical flow, however the solution does not converge for courant number 0.1, but this flow is similar to actually physical phenomena, can anybody please explain, how to choose optimum courant number value and any other means by which i can achieve convergence.
  Reply With Quote

Old   April 29, 2003, 20:39
Default Re: Courant Number
Alex Munoz
Posts: n/a

I apologize for delaying my response until someone else with better understanding reply. However, It seems that nobody wants to lead you question. Therefore allow me to try without having total accuracy of my answer.

Courant number defined as the time for a fluid move only a fraction of the grid spacing Äx in a time step (Pope S.B. 2000)

k^0.5*del time/del space= 1/20

where k is the turbulent kinetic energy del time is the delta of time de space is the delta of space and 1/20 is the courant number

As a result, when you decrease the courant number you indirectly decrease the del time. In this way, the system is able to capture the periodicity of the flow field.

I hope this answer helps you

Alex Munoz
  Reply With Quote


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
IcoFoam unstability, courant number gets large! vivien OpenFOAM 10 July 23, 2013 12:48
Courant number fireman FLUENT 4 October 4, 2010 12:54
LES near wall model & courant number kasim CFX 5 March 16, 2008 19:23
IcoFoam parallel woes msrinath80 OpenFOAM Running, Solving & CFD 9 July 22, 2007 02:58
Courant number calculation - unsteady flow Kuba FLUENT 0 November 8, 2005 23:44

All times are GMT -4. The time now is 03:19.