Roughness in Saturne

[Minh Quan Nguyen]

Dear all,

I am new to Saturne and currently use it for the roughness studies of the wind turbine's blade.

I have a question about the way Saturne simulate the roughness impact in wall-function. More precisely, by chance, I have found a formula in the thesis report[1] concerning code Saturne:

u/u*=1/k*ln((dy+ks)/ks)

,where k,dy, and ks stand for kappa, first grid form wall and roughness respectively.

On the other hand, Ansys Fluent,  http://my.fit.edu/itresources/manuals/f ... ode253.htm , declares, in (7-13-x) ,the formula for roughness quite differently to the one above.

So i would be grateful if anyone can verify this formula and its validity in external flow.

Thanks in avance,

Quan.

[1] report here attached in French, page 55.