[denismaloir]

Hello!

I'm trying to model the opening of a valve with Comsol, but I'm having some trouble.

In fact, I have a high pressure vessel opening up on a closed tube. In essence, it resembles the shock tube. BUT the opening of the valve (18ms) makes it entirely different (no shock wave, quasi isentropic flow) and I would like to know how much (define at least the transient pressure and temperature field).

I thought of Comsol to try and solve that but I can't find how to define at border that is opening with respect to time (no heavyside function, here). I than thought of modeling the tube only with juste a normal pressure but I just get nothing.

I'm thus a little stuck here and would really appreciate any insight on how to do that kind of stuff. I'm not even sure I'm using the right program for this...

Thank you for your time!