CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > SU2

SU2 Residuals

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 8, 2013, 05:52
Default SU2 Residuals
  #1
Member
 
Roberto Pieri
Join Date: Feb 2012
Location: Milan
Posts: 57
Rep Power: 14
robyTKD is on a distinguished road
Hallo,

I am not able to understand how residuals are calculated.
Are they the sum of all residuals in each cell or the maximum value in the computational domain?
And also, are values saved in the history.csv the log10 of the ratio Res/Res_ref, where Res_ref is a reference value, or simply the log10 of the residuals?

Thank you,
Roberto
robyTKD is offline   Reply With Quote

Old   February 15, 2013, 21:03
Default
  #2
Super Moderator
 
Francisco Palacios
Join Date: Jan 2013
Location: Long Beach, CA
Posts: 404
Rep Power: 15
fpalacios is on a distinguished road
The residual is the L-2 norm of the residual in the entire domain, and then we compute the log10.

My recommendation is to use tecplot (it is possible to obtain an evaluation copy), the paraview output is unsupported.

Cheers,
Francisco
fpalacios is offline   Reply With Quote

Old   February 17, 2013, 13:44
Default
  #3
Member
 
Roberto Pieri
Join Date: Feb 2012
Location: Milan
Posts: 57
Rep Power: 14
robyTKD is on a distinguished road
Thank you Francisco for the reply.

Cheers,
Roberto.
robyTKD is offline   Reply With Quote

Old   March 15, 2013, 08:19
Default SU2 residuals
  #4
New Member
 
malik
Join Date: Nov 2012
Posts: 19
Rep Power: 14
malik is on a distinguished road
Hi,

I am running Inviscid ONERA M6 mesh using the SU2 code. I have run it but it stops after 193 iterations, iwant to increase the number of iterations to to 1500 so plz can you tell what i have to change in cfg file.

Thanks in advance

Regards,
Malik
malik is offline   Reply With Quote

Old   March 15, 2013, 08:36
Default
  #5
Senior Member
 
Samuele Z
Join Date: Oct 2009
Location: Mozzate - Co - Italy
Posts: 520
Rep Power: 19
samiam1000 is on a distinguished road
Hi Malik,

this is the entry to change the max number of iterations
Code:
% Number of total iterations
EXT_ITER= 99999999999
Nevertheless, if it exits after 193 steps it is probably due to a convergence criteria.

Please, post your config file.
samiam1000 is offline   Reply With Quote

Old   March 15, 2013, 17:56
Default SU2 residuals
  #6
New Member
 
malik
Join Date: Nov 2012
Posts: 19
Rep Power: 14
malik is on a distinguished road
Hi samiam,
there is no error, i need to change convergence criteria

thanks
malik is offline   Reply With Quote

Old   June 17, 2013, 08:51
Default
  #7
Member
 
Roberto Pieri
Join Date: Feb 2012
Location: Milan
Posts: 57
Rep Power: 14
robyTKD is on a distinguished road
Hi,

I have other questions regarding residuals.

1. Where can I find the strings of the code where residuals are computed?
2. Is it possible to save residuals in the output file? I need to know at least the infinite-norm of residuals.
3. When running SU2_CFD, it prints "Maximum residual: -3.8985e+00, located at point 49659."; I think it is the maximum Res(rho) in the domain, is it right?

Cheers,
Roberto
robyTKD is offline   Reply With Quote

Old   March 31, 2016, 22:55
Default
  #8
OVS
New Member
 
Oliver V
Join Date: Dec 2015
Posts: 17
Rep Power: 11
OVS is on a distinguished road
I'm sorry but your answer about the residuals is not clear to me. I get you use the RMS norm on the residuals, but I'm still wondering about the second question from Roberto:

Quote:
Originally Posted by robyTKD View Post

are values saved in the history.csv the log10 of the ratio Res/Res_ref, where Res_ref is a reference value, or simply the log10 of the residuals?

Roberto
in other words, are the calculated residuals relative or absolute?

(My guess is they are absolute since you only mentioned the L-2 norm... but I need to ask).

Thanks,
Oliver
OVS is offline   Reply With Quote

Old   April 5, 2016, 19:46
Default
  #9
New Member
 
Tansu
Join Date: Apr 2014
Location: Turkey
Posts: 16
Rep Power: 12
tsevine is on a distinguished road
Quote:
Originally Posted by robyTKD View Post
Hi,

I have other questions regarding residuals.

1. Where can I find the strings of the code where residuals are computed?
2. Is it possible to save residuals in the output file? I need to know at least the infinite-norm of residuals.
3. When running SU2_CFD, it prints "Maximum residual: -3.8985e+00, located at point 49659."; I think it is the maximum Res(rho) in the domain, is it right?

Cheers,
Roberto
Hi Roberto,

for your 3rd question, as far as i know you are right, it is res(rho).

Regards,
Tansu
tsevine is offline   Reply With Quote

Reply

Tags
residual


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
Welcome to the Stanford University Unstructured (SU2) forum! economon SU2 0 January 7, 2013 03:48
New SU2 Forum Opened at CFD Online pete Site News & Announcements 0 January 5, 2013 18:59
judging convergence through residuals MachZero Main CFD Forum 7 December 25, 2012 13:18
Strange residuals of the Density Based Solver Pat84 FLUENT 0 October 22, 2012 16:59
Convergence - scaled vs unscaled residuals HS FLUENT 1 November 7, 2005 06:45


All times are GMT -4. The time now is 12:53.