[Lorena]

I am making a simulation in a square (2D) of 1cm X 1cm of an Heterogeneous Reaction using the VOF option for the multiphase model. I'm working with two phases, the primary phase is gas (compound by two species) and the secondary phase is liquid (compound by two species too). I consider it a transient process.

The heterogeneous reaction develops in the next manner:
a*A(L) ---> b*B(g) + c*C(L) , this means that the liquid reactive produce two products one in gas phase and the other in liquid phase.
I used a UDF for the reaction rate function.

I display the mass fraction contours for each species and they are well (see mass fraction contours T1) but after a certain time my results change and are incoherents as you can see in the figure (mass fraction contours T2).
Does anyone know why this happens?

I will appreciate any comment.

Regards,

Lorena