Now i'm trying to model the concentration in respect of time and space and that's why i'm using PDE solver. However why it does not work and it gave en error that "it found singularity while evaluating the expression.
Help please ((
The difference between the file 1 and file 2 that you sent is in the argument you put in the PDE solver. But is that affecting the result?
Because i'm trying your second file and it seems like it does not work again