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

SIMPLE BCs for flow in parallel plates

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

Like Tree1Likes

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 21, 2015, 08:22
Default Residuals vs convergence
  #21
New Member
 
Join Date: Jul 2015
Posts: 18
Rep Power: 7
kabz is on a distinguished road
So i've implemented residuals (rms residuals) and also convergence between two iterations (rms convergence). I get oscillating residuals but all below 1e-5 whereas my convergence is monotonically decreasing. The velocity profiles predicted look okay. So which should i use as my stopping criteria, the residuals or the convergence?
Attached Files
File Type: txt residuals and convergence.txt (634 Bytes, 2 views)
kabz is offline   Reply With Quote

Old   September 21, 2015, 08:53
Default
  #22
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 5,686
Rep Power: 60
FMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura about
Quote:
Originally Posted by kabz View Post
So i've implemented residuals (rms residuals) and also convergence between two iterations (rms convergence). I get oscillating residuals but all below 1e-5 whereas my convergence is monotonically decreasing. The velocity profiles predicted look okay. So which should i use as my stopping criteria, the residuals or the convergence?
difference bewteen two iterations is not meaningful for the real convergence
FMDenaro is offline   Reply With Quote

Old   September 21, 2015, 09:03
Default
  #23
New Member
 
Join Date: Jul 2015
Posts: 18
Rep Power: 7
kabz is on a distinguished road
Quote:
Originally Posted by FMDenaro View Post
difference bewteen two iterations is not meaningful for the real convergence

Can I use both? If i was to rely on residuals alone, my algorithm would stop within 2 or 3 iterations (since they are always below 1e-5)
kabz is offline   Reply With Quote

Old   September 21, 2015, 10:31
Default
  #24
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 5,686
Rep Power: 60
FMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura about
Quote:
Originally Posted by kabz View Post
Can I use both? If i was to rely on residuals alone, my algorithm would stop within 2 or 3 iterations (since they are always below 1e-5)
the residual must diminuish below such value
FMDenaro is offline   Reply With Quote

Reply

Tags
incompressible flow, parallel plates, simple

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Running parallel case after parallel meshing with snappyHexMesh? Adam Persson OpenFOAM Running, Solving & CFD 0 August 31, 2015 22:04
radiation b/w parallel plates str6073 FLUENT 0 November 18, 2013 07:42
Injection between parallel plates, homogenous mode Terje CFX 7 September 7, 2008 19:51
Flow between 2 parallel flat plates pelli FLUENT 2 July 14, 2007 09:59
Parallel Computing Classes at San Diego Supercomputer Center Jan. 20-22 Amitava Majumdar Main CFD Forum 0 January 5, 1999 12:00


All times are GMT -4. The time now is 14:37.