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

 January 18, 2008, 03:57 about Courant number #1 Daniel Guest   Posts: n/a During calculation, my Courant number was larger than 1, then, is my outcome correct? what does Courant number really mean? Is it only for watching the stability? What if some of my time step's largest courant number is larger than 1 (or 5 or what)? In what limitation can I believe my solution is good? Many thanks, Daniel

 January 19, 2008, 22:23 Re: about Courant number #2 Usman Guest   Posts: n/a Courant number is stability as well as accuracy requirement. I order to have accurate solution you should keep it close to unity. Large courant number may improve the stability of simulation but it will be at the cost of accuracy. Usman

 January 20, 2008, 12:24 Re: about Courant number #3 Deepak Guest   Posts: n/a I also believe that is also deals with convergence, as when my solution starts diverging, lowering your Courant no is a good option.. Please correct me if i am wrong. Thanks, Deepak

 February 2, 2008, 14:47 Re: about Courant number #4 pankaj Guest   Posts: n/a hi, Courant number is responsible for stability of explicit scheme. If, you use implicit scheme then you dont have to think for courant no. But, if it is explicit , then, if it cross 1, your code will diverge....so, always use less courant no. usually 1/4......

 February 9, 2008, 02:58 Re: about Courant number #5 Daniel Guest   Posts: n/a Hi there, thank you all. If my discretization schemes of temporal and convective and viscous terms are implicit, but my pressure terms are explicit. (you know, I am trying to use OpneFOAM). So, 1. do I need to think for courant no.? 2. what do you mean by saying " use less courant no. usually 1/4", are there any references that I can rely on? 3. Again I want to know, whether my result is "correct" once my courant number was larger than one during calculation? 4. What's the relationship between "stable" and "correct"? I mean what if my courant no. is, say 2 or 3, of which you say it is unstable, can i believe my result to be correct? Must I be concerned for stability all the way? Thanks for your patience. And finally, Happy new year to you all. (I 'm from China) Daniel

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post vivien OpenFOAM 10 July 23, 2013 12:48 fireman FLUENT 4 October 4, 2010 12:54 kasim CFX 5 March 16, 2008 19:23 msrinath80 OpenFOAM Running, Solving & CFD 9 July 22, 2007 02:58 Kuba FLUENT 0 November 8, 2005 23:44

All times are GMT -4. The time now is 21:46.