y+ calculation on rough walls

[MaximeO]

Hello,

Does anyone knows how exactly is calculated the y+ on a rough wall (on code_saturne v8.0) ?

I have searched in the theory guide (https://www.code-saturne.org/documentat ... theory.pdf p.58-60) but the rough wall part doesn't really answer this question.

The thing is, when I'm looking at my results, the y+ computed by code_saturne doesn't correspond to the y+ I have calculated with the theoretical formula and the computed wall shear-stress, and there is a huge difference ( on code_saturne while I calculated ), but I may be missing a point here ?

Best regards,
Maxime