Learning Forum

[David Garner]

Hi there. I am modeling solidification and melting within a metal lattice structure unit cell attached to a duct. The model is half of the duct and is surrounded by unit cells of the lattice. I would like to examine the behavior of heat transfer in the fluid, lattice, and phase change material over iterations of the model to simulate a longer duct and structure. The issue I am coming across is that if I create a periodic boundary, it includes the inlet, lattice, and filled in phase change material (PCM). I cannot set the initial conditions for the inlet without doing that to the lattice and PCM as well, but I just want to set the inlet initial conditions. I don't want to place a pressure gradient or mass flow on the PCM. I'm not sure how that will affect the simulation as the pcm melts. The only thing I want to control is the inlet, but then I want to create a periodic model to see that initial flow effect on the heat transfer of a longer duct.

For a periodic boundary condition that includes solid and fluid regions, should I neglect the solid region, assuming there is no impact for whatever pressure gradient or mass flow I put down? 

Any advice would be appreciated.

[Rob]

Periodic zones can't be bridged by solid (as in not fluid) zones. I'm not sure how solidification/melting will behave as I'd expect the end result to be all liquid or solid?