[andreasp]

Hi all!

I simulate mass transfer problems by solving advection-diffusion (and possibly reaction) equation with a finite element method.

Numerical instabilities and insufficient mesh resolution sometimes lead to non-physical negative concentration values. I heard somewhere that these problems can be elegantly circumvented by reformulating the transport equations in terms of log(c) -- instead of solving for c directly.

- Does anyone here have experience with such log(c)-problems?
- I'd be happy if anyone could point me to a publication on this topic!
- How will a zero concentration be expressed in terms of log?
c=0 ==> log(c)=-inf ...?

Thanks for your help!
Andreas