[shrieks08]

Hello all,

I am developing a model for the combustion of a fuel pellet placed inside a furnace. There is air flow enabled in the furnace, which I would think "seeps" oxygen inside the porous pellet. Before I went into the complete heat, mass and reaction coupling, I just wanted to to run a study with just fluid flow interfaces defined. I am using the laminar flow interface for the furnace domain and brinkman equations for the porous pellet domain.

Since I defined the geometry as a union, I would assume that COMSOL automatically treats internal boundaries with continuity conditions, however, when I checked the results I see that the continuity is not maintained.

Currently, the interfaces between the pellet and the furnace are defined as walls, which I assumed would be overridden automatically. Now I think I need to add some additional B.Cs to let COMSOL know that there is an interface between the pellet and the furnace where continuity needs to be maintained. Or do I need to define identity pairs? Or is there anything else that I am missing. I am also having some trouble determining the source and destination boundaries while defining identity pairs.

I am attaching an annotated image with some information that might be useful.

Any help is much appreciated, thank you!