Off-diagonal entries in matrix of Relative Diffusivity

[Ilona Glatt]

Hi,
when I calculate the relative diffusivity, I get a complete matrix as a result. Can someone explain the meaning of the off-diagonal entries?
Thanks,Ilona

[Aaron Widera]

Hello,
of course we can:
If you calculate the Diffusivity in x-direction, the entry in the main diagonal x_11 gives you the diffusivity in x-direction. The off-diagonal entries x_12, x_13, x_21 and x_31 give you the amount of diffusion going into y- and z-direction although the driving force, the concentration gradient, is only given in x -direction.
The same goes for Diffusivity in y- and z- direction.

Was that understandable?

[Ilona Glatt]

Yes. That was very clear, thank you!