Hi all,

I have to study the water evaporation of a ceramic tile in a drier, where a hot air flow get out the water from the tile. I use cfx4 My question is: how I can simulate the copuled heat and mass trasfer from solid to gas phase?

Thanks a lot

Alessandro

I don't have any experience with this cfx4, but the ceramic tile problem seems to be very interesting. I think, the drying process is normally a slow one to prevent cracks. Your are not talking about something like a few seconds of time. That gives us a semi-steady state approach to model the gas flow and the tile separately. So, you can compute the gas flow first to establish the condition on the boundary of the tile. I don't think the evaporation from the tile will upset the gas flow conditions. Once you have the boundary conditions established, you can try to solve the tile problem. You may be able to treat the tile problem in two steps1) the early phase of heat conduction, to bring the tile to certain temperature , (2) once the water becomes the vapor inside the tile, you can simulate the diffusion problem with the concentration of the water vapor at the boundary set equal to a low value ( condition in the gas flow). The diffusion of the water vapor is simular to the diffusion ( conduction) of heat in the tile, except that you need to model the diffusion coefficient.