Modelling and simulation of the ultrasound propagation at the interface deposited layer-base material through metal spraying

Hello,

I am trying to understand how Comsol works. I don't know to work with this program.
I've received a homework and I am trying to model the ultrasound propagation at the interface deposited layer-base material through metal spraying. My model is made of two concentric cylinders. One is made of structural steel and the other of AISI 4030.
Please, can anybody help me to resolve my problem? I am desperate