[CFDUser29]

Hello everyone,

I have searched a bit, but I didn't find a solution, so I hope one can help.
I try to simulate dispersion of methane in air, given that I work in molar fraction (mol^-1). The case is the following :

Inlet 1 : Air, mol_frac = 1
Inlet 2 : Air, mol_frac = 0.92 & CH4, mol_frac = 0.08

Of course I also impose conditions on speed as well as the turbulent kinetic energy.
I guess that to do what I want, I can simply create two dictionaries called "Air" and "CH4" but I would like to tell the solver the density of both gases, but I don't know how to do that. Perhaps in Physical Properties.

If I add two species in Physical Properties, do I have to change the viscosity model that is defined as below ?

viscosityModel constant;

nu              [0 2 -1 0 0 0 0] 1.42e-5;

This is quite urgent, so if anyone knows I would be very pleased to learn his solution. I precise that I work with simpleFoam, and I might certainly work with pisoFoam later one the steady case is correctly set.

[Yann]

Hello,

You cannot do this with simpleFoam, a better approach would be to use reactingFoam (without reactions) which will do just what you are trying to achieve. It will allow you to define multiple species, each one having its own thermophysicalProperties.

Cheers,
Yann

[CFDUser29]

I will try it and tell you if that works. Thanks