residual

nimasam · January 17, 2011, 07:04

hi dear foamer
could u please tell me how residual calculate in open Foam process?
im using interFoam, whats the meaning of residual for alpha1?
is it the average of errors in each point? or maximum error in the whole domain?
whats up if it is up rising?

thanks in advance

Chris Lucas · January 17, 2011, 08:14

Hi,

have a look at the PhD These of Prof. Jasak.

http://powerlab.fsb.hr/ped/kturbo/OPENFOAM/docs/

Regards,
Christian

nimasam · January 17, 2011, 13:09

thank Christian for ur suggestion

for who likes to know what the residual is, can take a look at pages (173-181)
but my questions still are opening! according to Prof. Jasak thesis, error calculate in each cell for each field from its transport equation, then it is normalized, but i still dont know what's the written residual in log file? is it the average of residual in each cell?or its the maximum residual among all cells ?

Chris Lucas · January 18, 2011, 04:23

Hi,

there is a tool in OpenFOAM ext. to plot the local residuals (or have a look at)

http://www.cfd-online.com/Forums/ope...residuals.html

You could compare the results of the local residual with the one in the log file

Regards,
Christian

nakul · January 20, 2011, 05:06

Hi Chris,

Did you find out the details about the residuals?

Is it the average of residual in each cell or is it the maximum residual among all cells or is it the residual calculated in some specific cell only?

January 17, 2011, 07:04	residual	#1
nimasam Senior Member Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,267 Blog Entries: 1 Rep Power: 25	hi dear foamer could u please tell me how residual calculate in open Foam process? im using interFoam, whats the meaning of residual for alpha1? is it the average of errors in each point? or maximum error in the whole domain? whats up if it is up rising? thanks in advance

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January 17, 2011, 08:14		#2
Chris Lucas Senior Member Christian Lucas Join Date: Aug 2009 Location: Braunschweig, Germany Posts: 202 Rep Power: 18	Hi, have a look at the PhD These of Prof. Jasak. http://powerlab.fsb.hr/ped/kturbo/OPENFOAM/docs/ Regards, Christian

January 17, 2011, 13:09		#3
nimasam Senior Member Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,267 Blog Entries: 1 Rep Power: 25	thank Christian for ur suggestion for who likes to know what the residual is, can take a look at pages (173-181) but my questions still are opening! according to Prof. Jasak thesis, error calculate in each cell for each field from its transport equation, then it is normalized, but i still dont know what's the written residual in log file? is it the average of residual in each cell?or its the maximum residual among all cells ?

January 18, 2011, 04:23		#4
Chris Lucas Senior Member Christian Lucas Join Date: Aug 2009 Location: Braunschweig, Germany Posts: 202 Rep Power: 18	Hi, there is a tool in OpenFOAM ext. to plot the local residuals (or have a look at) http://www.cfd-online.com/Forums/ope...residuals.html You could compare the results of the local residual with the one in the log file Regards, Christian

January 20, 2011, 05:06		#5
nakul Senior Member Nakul Join Date: Apr 2010 Location: India Posts: 147 Rep Power: 16	Hi Chris, Did you find out the details about the residuals? Is it the average of residual in each cell or is it the maximum residual among all cells or is it the residual calculated in some specific cell only?