Soy drying simulation
 

Hello, I'm currently trying to work out how to proceed in the simulation of a fixed bed dryer. I'm using the Euler granular multiphase model (with packed bed enabled), aswell as the species model (soy-water(liquid), air-water(vapour)). I'm trying to verify the behaviour of different models for the mass transfer, but I can't seem to make the species-mass-transfer model work. I'm using Equilibrium Ratio, and ranz-marshall for the from and to phase, but can't properly understand what the Mass Fraction Equilibrium Ratio means. Is it simply the mass concentration of water in soy divided by the mass concentration of water in the water? If so, the boundary conditions for the air at the inlet considers a completely dry air, with a fraction of water of 0, which wouldn't allow a proper value. Plus, this value is constantly changing as the operation goes on, since water is removed from the soy to the air. Should I write an UDF? Am I using the right model?

Thanks in advance for your help.