Wich model in gas-gas (VOF, MM or EM)
 

Hi everybody
I want to modeled an electric arc in a perfect gas (two fluid: electrons and heavy species (ions and neutrals)), with the following assumptions:
the flow is laminar, steady, equilibrium prevails among electrons and heavy species but at different temperatures.
wich model appropriate to this case:

the VOF Model
the Eulerian model
or
the Mixture Model

Thank you for any answer or suggestion