[pifou74]

Hello everybody,

I'm looking for an interpolation of the diffusion coefficient at the faces in Fluent.
I have found in the routines prop.h two routines enabling mean harmonic calculation. The first one is :

#define DIFFUSION_COEF_AVE(d0,d1)((ABS((d0)+(d1))<SMALL_S) ? 0.0 : (2*(d0)*(d1)/((d0)+(d1))))

and the second one :

#define DIFFUSION_COEF_AVE_LONG0(g0,g1,d0,d1,r)\
((((d1)*(g0)+(d0)*(g1)+(r)*(g0)*(g1))==0.0) ? 0.0 : \
((d0)+(d1))*(g0)*(g1)/((d1)*(g0)+(d0)*(g1)+(r)*(g0)*(g1)))

The first one is easy to understand (harmonic mean on a regular grid).

The second one is more mysterious for me. I presume that it is used in case of non uniform and non structured grid.
I presume that g0 and g1 are the diffusion coefficients at respectively cells 0 and 1. I can imagine that d0 and d1 are the distance between the cells and the face center. Nevertheless, I don't understand what can be the variable r?? I don't understand anymore the formulation.

If someone has already used this function or has an explanation it would help me a lot.

Thank you