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

What is the difference between "includefunc residuals" and the residuals in log-file?

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

Like Tree1Likes
  • 1 Post By clapointe

Reply
 
LinkBack Thread Tools Display Modes
Old   July 13, 2018, 12:40
Default What is the difference between "includefunc residuals" and the residuals in log-file?
  #1
Member
 
Bruno
Join Date: Jun 2016
Location: Siegen, Germany
Posts: 59
Rep Power: 4
MBttR is on a distinguished road
Hi,

I'm trying to run an inviscid, incompressible flow (Euler equations) around a wing with simpleFoam with nu set to zero. I'm trying to judge convergence and noticed that the final residuals in the log-file (by running simpleFoam > log) are in the order of e-09, whereas the residuals in the .dat file generated with "includefunc residuals" are in the order of e-02. What is the difference between the two? Why are they not the same?



Here's the last log entry:


Code:
Time = 3000

DILUPBiCG:  Solving for Ux, Initial residual = 0.00244323, Final residual = 6.17655e-10, No Iterations 8
DILUPBiCG:  Solving for Uy, Initial residual = 0.0121557, Final residual = 7.31898e-09, No Iterations 7
DILUPBiCG:  Solving for Uz, Initial residual = 0.00547038, Final residual = 2.36399e-09, No Iterations 8
DICPCG:  Solving for p, Initial residual = 0.0347422, Final residual = 8.60062e-07, No Iterations 75
time step continuity errors : sum local = 2.02144e-08, global = -2.11615e-09, cumulative = -2.57245e-07
ExecutionTime = 235.96 s  ClockTime = 236 s

End
Here's the last residuals.dat entry:


Code:
# Time            p                 Ux                Uy                Uz 

3000              3.474220e-02    2.443230e-03    1.215570e-02    5.470380e-03
Thanks!

Bruno
MBttR is offline   Reply With Quote

Old   July 13, 2018, 18:29
Default
  #2
Member
 
Join Date: Aug 2015
Posts: 90
Rep Power: 4
clapointe is on a distinguished road
It looks like the initial residuals are those pulled by the function, not the final ones.

Caelan
MBttR likes this.
clapointe is offline   Reply With Quote

Old   July 16, 2018, 09:57
Default
  #3
Member
 
Bruno
Join Date: Jun 2016
Location: Siegen, Germany
Posts: 59
Rep Power: 4
MBttR is on a distinguished road
Quote:
Originally Posted by clapointe View Post
It looks like the initial residuals are those pulled by the function, not the final ones.

Caelan

Wow, well spotted, thanks!
MBttR 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



All times are GMT -4. The time now is 02:31.