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December 7, 2011, 09:35 |
UEqn.relax()
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#1 |
New Member
Maike
Join Date: Dec 2010
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In the PIMPLE algorithm the momentum equation is defined and afterwards used by UEqun.relax(). As far as I could figure out this means that an underrelaxation is applied, but what does this relax do exactly or where is it defined in the code?
Thanks for any help! Maike. |
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June 20, 2013, 05:11 |
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#2 |
Member
Join Date: Mar 2013
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Hi,
Do you find the answer at your question? I have the same question. Moreover in my fvSolution file I don't specify any under relaxation factor.. Thanks |
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July 2, 2013, 23:14 |
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#3 |
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Santiago Marquez Damian
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Santiago MÁRQUEZ DAMIÁN, Ph.D. Research Scientist Research Center for Computational Methods (CIMEC) - CONICET/UNL Tel: 54-342-4511594 Int. 7032 Colectora Ruta Nac. 168 / Paraje El Pozo (3000) Santa Fe - Argentina. http://www.cimec.org.ar |
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July 3, 2013, 01:41 |
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#4 |
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Ehsan
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it isn't clear how the relaxation is applied even in the code.
Where alpha is defined? Can we set it and whats alpha at all? How relaxation is applied?
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July 3, 2013, 01:51 |
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#5 |
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Bernhard
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See line 658 of the same file, the relax() member function without argument is defined. Then, the parameter are read from a file, as here http://foam.sourceforge.net/docs/cpp...ce.html#l00313
Note that on the docs, you can search for member functions that you want to find (I used it on "equationRelaxationFactor") |
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July 3, 2013, 05:17 |
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#6 |
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So if I don't specify any relaxation factor in fvSolution file the relaxation is not applied to equation,it's right?
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July 3, 2013, 08:39 |
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#7 |
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Ehsan
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its not obvious enough to find out how automatically this relaxation is implemented yet,how can avoid relaxation?
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. Last edited by immortality; July 3, 2013 at 15:10. |
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July 3, 2013, 13:06 |
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#8 |
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Mohsen KiaMansouri
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Thanks Santiago & Bernhard
If you don't specify any under relaxation factor then the default is zero Code:
00099 eqnRelaxDefault_ = 00100 eqnRelaxDict_.lookupOrDefault<scalar>("default", 0.0);
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