Pressurized release of gas using ANSYS Fluent: are these settings correct?
 

I am currently trying to model the pressurized release of air from a 1000 psi tank into a chamber. I'm currently using Density-based settings because I couldn't seem to get a solution when I used Pressure-based settings.

This is how I set up the model:
1) Set everything as a wall, except for the furthest face which I defined as a Pressure outlet at 1 atm;
2) initialize the whole fluid domain as 1atm air, 0 velocity;
3) Adapt > Region > Choose coordinates so the tank points are selected;
4) Patch region as 1000 psi. The pressure contour plot is correct initially.

I just want to know if these settings are correct, because when I ran the simulation the tank pressure remained at a constant 1000 psi instead of going down like it should in real life.

Anyone? I have pretty much setup everything, just probably some minute tweaking of the settings.