code_saturne User's Forum

Hi,
In the k-epsilon model, I understand that I should use the scalable wall function rather than the 2-scale wall function when my mesh is too refined near the walls, but what are exactly the equations behind this scalable wall function? In particular, how is temperature near the wall computed?
Thanks for your help,
Axel

Can anyone please answer this question?

I'm no the most indicated to answer this question, but you may check the Theory manual in chapters II-2 and II-17. Also take a look at this thread also related to temperature in Code_Saturne: http://caelinux.com/CMS/index.php?option=com_joomlaboard&Itemid=52&func=view&id=4542&catid=18

Hi Axel,
The scalable wal-functions are not described in the theory manual... (work on progress here ;) but the underlying idea is to "push" the wall far enough from the first-cell off-wall to make the code think it is a high-Reynolds region. Think about not using y + in the logarithmic law, but y + + D.
This is really a way to avoid mesh issues, not a proper way of dealing with near-wall turbulence, especially when modelling heat-transfer.
David