[rodrigovime]

Hello everyone,
I have to include a source term in my energy conservation equation using a UDF, but i have a divergence operator that i don't know how to include in the code. Does anyone have solved a similar problem?
The equation I need to include is:
[/math] - \nabla \cdot ((h_1-h_2)\frac{k}{c_p}\nabla Y_1)[/math]
Thanks for your help

[karam_j]

Hello,
you can use Divergence/Gauss's Theorem to translate this term into fluxes through the cell faces. Basically, you do a cell face loop and calculate the flux through each face, then add these up into a single term and apply it to the cell as a source. Look out for face value interpolation wherever necessary.

[rodrigovime]

Thank you very much for that idea. Following it, I managed to calculate a diffusion-like term for a simple case to test my UDF with succes. Here's the UDF i wrote for 2D rectangular coordinates.