UEqn.relax()
 

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.

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

http://foam.sourceforge.net/docs/cpp/a04763_source.html, line 524

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?

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")

So if I don't specify any relaxation factor in fvSolution file the relaxation is not applied to equation,it's right?

its not obvious enough to find out how automatically this relaxation is implemented yet,how can avoid relaxation?

Thanks Santiago & Bernhard
If you don't specify any under relaxation factor then the default is zero