LPCVD : Low Pressure Chemical Vapor Deposition Model

Hi everyone,

I am new at COMSOL. I've been working on modeling of a Low Pressure Chemical Vapor Deposition system for a few weeks now. Here are the characteristics:
_Two gases in the chamber
_A heater around the chamber
_Fixed temperature of T=700°C
_Thermocouple in the chamber
_Fixed pressure Output P=200mTorr
_Fixed gas input : 200 sccm

My goal is to simulate and track the flows of particles and heat in the chamber. (In order to say if the chamber geometry is optimum or if it could be improved)

For now, I've mainly worked on the heat transfer physics.

My first questions for now are :
_Have you heard of any already existing 3D COMSOL model for this kind of setup (CVD)?
_For a the last few days I've been trying to create user-defined meshes. But when I try to compute them, COMSOL would just create a new one and not use the one I created. Do you have any idea of what I might be missing?

I'm still discovering COMSOL, maybe I missed something...

Thank you for your help!

U