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

how to converge the solution for fine mesh

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 12, 2006, 00:44
Default how to converge the solution for fine mesh
  #1
kathiravan
Guest
 
Posts: n/a
hi experts i am doing one problem related to heat transfer in star cd. my prob is one heated cylinder is placed inside a square cavity. now i want to find out heat transfer coefficient around the cylinder. for coarsh mesh the solver converges very quickly. but for fine mesh it will not converges. for using SIMPLE algorithm it will diverges immeadialy. but my boundry condition everything same for coarsh and fine mesh. so how to attack this problem from very fine mesh. after that can you tell me how to plot graph for theta verses heat transfer coefficient.

  Reply With Quote

Old   July 12, 2006, 04:20
Default Re: how to converge the solution for fine mesh
  #2
Zamir Rashid
Guest
 
Posts: n/a
Try using under relaxation factors for the solved parameters.
  Reply With Quote

Old   July 12, 2006, 07:04
Default Re: how to converge the solution for fine mesh
  #3
DenizeN
Guest
 
Posts: n/a
Try to read about y+ and turbulence models in user guide.
  Reply With Quote

Old   July 20, 2006, 00:06
Default Re: how to converge the solution for fine mesh
  #4
kathir
Guest
 
Posts: n/a
i am using only laminar flow
  Reply With Quote

Old   July 20, 2006, 02:37
Default Re: how to converge the solution for fine mesh
  #5
DenizeN
Guest
 
Posts: n/a
then your flow have complex structure, use transient or pseudo-transient solver. With coarse mesh you smooth flow structure and solution converged (real structure of your flow is more comlicated).
  Reply With Quote

Old   August 11, 2006, 01:30
Default Re: how to converge the solution for fine mesh
  #6
kathir
Guest
 
Posts: n/a
hi DenizeN

thanks for responce. in my problem i activate to print the parameter values( temp, velocity etc) of each cell. at the time the result shows the negatve temp values. how is it possible. because my air temp is 25 c and fin base temp is 100 c. but it shows surrounding air temp is less than 0. but in contour plot it not shows the negative values. but print values shows the negative values. please give me what is the mistake in my approach thank you sir
  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 should I do if the solution didn't converge? Beeny FLUENT 6 August 27, 2011 00:04
New geometry in tutorial mixer2d unphysical solution for fine mesh christinasmuda OpenFOAM Running, Solving & CFD 6 January 16, 2009 08:11
steady solution on fine mesh Flo Main CFD Forum 2 May 31, 2008 14:55
Solution Does Not Converge Rif Main CFD Forum 3 March 7, 2008 06:33
what to do when solution doesn't converge? Jenny CFX 5 January 28, 2004 05:00


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