CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Courant number

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

Reply
 
LinkBack Thread Tools Display Modes
Old   December 26, 2008, 02:42
Default hi, i am doing a simulation
  #1
Senior Member
 
weihong yao
Join Date: Mar 2009
Posts: 117
Rep Power: 8
ivanyao is on a distinguished road
hi,
i am doing a simulation,why the courant number get smaller as the time go?does anyone meet the problem ever?
ivanyao is offline   Reply With Quote

Old   December 26, 2008, 05:28
Default hi, which kind of solver do
  #2
Senior Member
 
Tian
Join Date: Mar 2009
Location: Berlin, germany
Posts: 102
Rep Power: 8
tian is on a distinguished road
hi,

which kind of solver do you used for your case?

Bye
Tian
__________________
BIM HVACTool, The Green Building Simulation Tool for OpenFOAM, Energy Plus and Radiance.
tian is offline   Reply With Quote

Old   December 29, 2008, 16:27
Default sometimes it can happen, basic
  #3
Member
 
antonio segalini
Join Date: Mar 2009
Posts: 75
Rep Power: 8
antonio_ing is on a distinguished road
sometimes it can happen, basically because the solution is converging and the shear is becoming smaller than at the beginning... Usually it could be a good thing
antonio_ing is offline   Reply With Quote

Old   December 30, 2008, 05:03
Default now it is ok! thank you!
  #4
Senior Member
 
weihong yao
Join Date: Mar 2009
Posts: 117
Rep Power: 8
ivanyao is on a distinguished road
now it is ok!
thank you!
ivanyao is offline   Reply With Quote

Old   December 30, 2008, 05:15
Default is there someone good at write
  #5
Senior Member
 
weihong yao
Join Date: Mar 2009
Posts: 117
Rep Power: 8
ivanyao is on a distinguished road
is there someone good at write new BC?I AM in trouble in it.could someone give me a hand.
ivanyao is offline   Reply With Quote

Old   January 5, 2009, 05:25
Default Hi, FOAMers, I am learning
  #6
New Member
 
Su Xiaohui
Join Date: Mar 2009
Location: Singapore
Posts: 29
Rep Power: 8
sxhdhi is on a distinguished road
Send a message via Skype™ to sxhdhi
Hi, FOAMers,

I am learning OpenFOAM. Could anyone be kind to tell me what the definition of deltaCoeffs is appearing in the below codes? where is the length scale in the formula?

Thanks

Su Xiaohui

\*---------------------------------------------------------------------------*/

scalar CoNum = 0.0;
scalar meanCoNum = 0.0;

if (mesh.nInternalFaces())
{
surfaceScalarField SfUfbyDelta =
mesh.surfaceInterpolation::deltaCoeffs()*mag(phi)/fvc::interpolate(rho);

CoNum = max(SfUfbyDelta/mesh.magSf())
.value()*runTime.deltaT().value();

meanCoNum = (sum(SfUfbyDelta)/sum(mesh.magSf()))
.value()*runTime.deltaT().value();
}

Info<< "Courant Number mean: " << meanCoNum
<< " max: " << CoNum << endl;

// ************************************************** *********************** //
sxhdhi is offline   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
what exactly is the Courant Number ??? CFX Novice CFX 1 July 26, 2006 13:40
COURANT NUMBER Ferreira Main CFD Forum 23 February 26, 2006 19:10
Courant number freddie Main CFD Forum 1 September 11, 2005 13:27
courant number Jay FLUENT 1 October 1, 2004 03:18
On the Courant number . raintung FLUENT 3 May 7, 2003 06:03


All times are GMT -4. The time now is 19:28.