Learning Forum

[Zeska ZESKA]

How can one define a non-stoichiometric mixture considering the mixture of two gases? For example, I'm simulating the mixture of air and ethylene and I'm using the species transport model. When i defined teh mixture, I chose only two species: ethylene and air. Both inlets are pressure inlets. The only boundary condition I can set is the mass (or mole) fraction of ethylene. If the mixture has an equivalence ratio of 1, I set the mass fraction of ethylene equal to 1 for the fuel inlet and 0 for the other inlet and outlet. What should I do if the mixture has an ER of 0.8?

[Rob]

Then you'd set 0.2 or whatever the fraction comes out as.  Fluent solves for n-1 species, so if ethylene is the lower mass flow of the two species it'll solve for that and anything that's not ethylene is the other material (ie air).