Modeling hydrogen/air in an open-roofed enclosure
 

Hello everyone,

I'm working on modeling the flow of hydrogen through still air in an open-roofed 9x10 ft enclosure in Fluent (would CFX be better for this?). From what I've read online, I need to enable gravity and possibly use the Boussinesq approximations. I'm new to Fluent and CFD in general, and I've been trying to climb the learning curve on my own, but it's tough. If anyone could give me some pointers or direct me to a relevant tutorial to make the climb easier, I would greatly appreciate it.

Thanks!

A couple specific questions:

1. The tutorials I've seen model a round pipe as a single solid body, name the planar faces of the body as inlet and outlet, and the software figures out that the pipe is hollow, how to mesh accordingly, and which direction to flow. But what if I have a 9 ft x 9 ft enclosure with a 1/2" diameter source of hydrogen somewhere at the bottom? Do I model a small solid cylinder at the bottom of a solid cube and label the planar face of the cylinder as the inlet? How do I specify that the enclosure is filled with stationary air and the pipe is only releasing hydrogen?

2. Should I use the Volume of Fluids model, the Multiphase model, or something else?

An image of what I'm trying to do is shown below. Basically, I have an open 9 ft^3 enclosure with a 5" high floor vent at normal lab conditions. A hydrogen source is somewhere on the bottom of the enclosure, and the top is either fully open with no roof or has a cover with a hole in it. I want to model the path hydrogen takes to escape the enclosure.

https://i.imgur.com/WbLmGIA.png