# PDE in COMSOL with moving boundary

1. Apr 11, 2009

### kamran46

Hi all,

I want to know how can I solve a system of PDEs in COMSOL when the internal boundary is defined by another PDE.

More specifically consider this, where B is moving with time: (Lap means Laplacian)

dc1/dt = Lap (c1) , A < x < B : 1st PDE is defined between boundaries A and B.
dc2/dt = Lap (c2) , B < x < C : 2nd PDE is defined between boundaries B and C.
dc1/dx = k dc2/dx , at B : 3rd PDE defines the position of boundary B.

This is a simulation of two way internal oxidation in metals.

Thanks
Kamran

Last edited: Apr 11, 2009