Are Relaxation factors applicable to rhoCentralFoam?

immortality · December 4, 2012, 17:06

in rhoCentralFoam there isn't relaxation factors in fvSolution at all.how can add these parameters?is it suitable adding the relaxation factors for a transient problem?

immortality · December 5, 2012, 02:41

if just copy the lines from other cases it will be ok?

mkhm · May 24, 2018, 09:03

Did you find any answer for your question ?

RobertHB · May 24, 2018, 10:17

Afaik, the solver must call the .relax() function to use relaxation factors. As rhoCentralFoam does not contain this function i'd guess that it is not designed to use relaxation.

Furthermore, i think it is of no use to underrelax the equations of an transient solver. You want to achive convergence of your simulation during runtime, not force it to become convergent.

December 4, 2012, 17:06	Are Relaxation factors applicable to rhoCentralFoam?	#1
immortality Senior Member Ehsan Join Date: Oct 2012 Location: Iran Posts: 2,208 Rep Power: 27	in rhoCentralFoam there isn't relaxation factors in fvSolution at all.how can add these parameters?is it suitable adding the relaxation factors for a transient problem?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Relaxation Factors for Transient solvers	philippose	OpenFOAM Running, Solving & CFD	19	March 20, 2014 05:39
Purpose of relaxation factors	Mohsin	FLUENT	5	April 30, 2010 12:57
relaxation factors and time accuracy	Mike	Main CFD Forum	7	May 21, 2005 13:41
Relaxation Factors	Tim	Phoenics	3	June 30, 2004 03:03
relaxation factors	zhujianguo	Phoenics	1	August 5, 2003 07:17

December 5, 2012, 02:41		#2
immortality Senior Member Ehsan Join Date: Oct 2012 Location: Iran Posts: 2,208 Rep Power: 27	if just copy the lines from other cases it will be ok?

May 24, 2018, 09:03		#3
mkhm Member K Join Date: Jul 2017 Posts: 97 Rep Power: 9	Did you find any answer for your question ?

May 24, 2018, 10:17		#4
RobertHB Senior Member Robert Join Date: May 2015 Location: Bremen, GER Posts: 292 Rep Power: 12	Afaik, the solver must call the .relax() function to use relaxation factors. As rhoCentralFoam does not contain this function i'd guess that it is not designed to use relaxation. Furthermore, i think it is of no use to underrelax the equations of an transient solver. You want to achive convergence of your simulation during runtime, not force it to become convergent.