Interface disappearing
 

Hi!
I have a strange problem where the solid/fluid interface disappears the moment I start the run.
I'm trying to simulate condensation on a large, rectangular aluminum block that's cooled from below as shown in the sketch. The temperature of the bottom face of the block is set to 10 C and the initial temperature of the rest of the block and the domain is set to 30 C. For the gas phase, I have a mixture of air and water vapor and I'm using VOF and Fluid Film models (also tried it without VOF, just Multiphase and Fluid Film with the same result). There is no flow inside the domain and the outer walls of the domain are defined as outlets (or just walls I tried that too). For the time step I tried a whole range from 0.001 s to 1 s. I mesh the solid and the fluid (screenshot down below) and add an imprint operation after the meshing (but both geometries were also imprinted once before meshing). Now, using contacts, add an interface between solid and fluid and define a shell region on the outside of the block for the fluid film. If I highlight these two interfaces, they get highlighted pink. Now if I start the run, the heat is transferred inside the block, but there is no heat transfer between the solid and fluid region and also no condensation. If I stop the simulation and highlight these two interfaces again, nothing will happen. Any ideas what I'm doing wrong?


Attachment 96973

Attachment 96972