[Felggv]

Hi everyone,

I'm new to CFX and I'm trying to model and study umidity distribution in a room with the influence of an ar conditioner system.

As read in an example of Yunus' book (thermodynamics), we have the mass of each component of the atmosferic air (dry air + water vapour) but their volume are equal in a closed room, as it says. They're equal because both of them fullfil the room they're in.

What puzzles me is, when I'm editing my domain in CFX, it asks for the volume fraction of each fluid, so, if they occupy the same volume, what should I do? Should I use the mass fraction instead volume fraction?

Another thing I'd like to comment is that I'm not creating a new material that is the mixture of Air at 25ºC + Water Vapour at 25ºC, instead of that, I'm adding two fluids on the domain editor and using the homogeneous model for them. What's the best method for this application? Is there another method that would make my problem easier to solve?

At last, as I'm studying a transient case, is there any problem if I use the models of Water vapour and Air at 25ºC and set my initial temperature at 22ºC?

Sorry about the long text.

Thanks in advance,

Felipe.