Re: How to solve the problem of negative concentration

Hi,

Here is one trick to solve negative concentrations.

I made variable "C" which is defined by "if(c<0,eps,c)" under Definitions => Variables. Instead of concentration "c" I used variable "C". Now variable "C" is never below zero. Eps is very small number defined is Comsol.

Does this help you?

Best regard

Tero