OpenFOAM Multiphase Coupling Assistance

I am modeling multicomponent evaporation in OpenFOAM 10 using compressibleInterFoam within a VOF framework. The liquid phase is an incompressible multicomponent mixture, and the gas phase is a compressible mixture of inert and non-inert species. Each component evaporates independently following the Hertz–Knudsen equation, where the mass flux is driven by the difference between Raoult’s-law-based equilibrium pressure and a user-defined saturation pressure.

Evaporation induces latent heat removal at the interface, which is included in the energy equation and results in interfacial cooling. The study is conducted in a simple 2D closed domain (walls on all four sides), initially half-filled with liquid (test case: 0.7 H₂O and 0.3 O₂). The initial vapor pressure is below saturation, and evaporation continues until thermodynamic equilibrium is reached and the system pressure approaches saturation. I have a model but I have some coupling issues between volume fraction equation and species equation.