[Andrea23]

Hi;

I need help to calculate outbound diffusive flux. I think my problem is half solving/running and half post-processing.

I am doing simulations using a slightly modified scalarTransportFoam solver, shortly it solve the advection-diffusion equation for a transported passive scalar.

the passive scalar is everywhere >0 and on some boundary walls I am using the boundary condition:

type fixedValue;
value uniform 0;

physically there is an outbound diffusive flux near walls and I would like to calculate it. Is there an automatic way to do it on Openfoam or paraview?

Mathematically is the 0 value that flow inside from wall instead of >0 value near wall that flow out? I don't know if it is clear what I mean.

Otherwise I thought to calculate it manually: probe the value in the cell near wall and calculate the flux using flick law in matlab, do you think it is a good estimation?
Is there a way to probe value for a surface instead of a point?
I tried putting in probe declaration

Surface
(
"boundary wall name"
)

but it did not work, i can successfully only probe value in points

or if you have another way to calculate the outbound diffusive flux I am open to suggestion.

Thanks for the help

[GregNordin]

Were you able to figure out how to calculate diffusive flux through a surface? I need to do something similar.