How to write and solve this pde system

Answer 1

[Torsten]

If your system is in one spatial dimension, use "pdepe".

Examples on how to set up your problem are given here:

https://de.mathworks.com/help/matlab/ref/pdepe.html

[Ahmed Ali]

Thank you Dr. for your answer, my system are 3 dimension.

[Torsten]

Then maybe the PDE toolbox can help.