Reply To: How to setup multiphase mixture? (simulating incubation of agar)

[Rob]

You may struggle with viscosity values like that as any motion will run into the very viscous flow and that won't help solver stability. You may also find the water evaporation is a function of diffusion in the agar as much as the flow in the gas phase. Phase change will be OK, but again it's going to be difficult to ensure that only occurs at the surface of the agar: the Fluent models look at phase change on a cell basis everywhere rather than at specific locations. 

The bigger problem may be time scale. Time steps may be down in the 0.0001s range, so for 4 days you may struggle.