Boundary condition for solid region at inlet
 

Dear Friends,

I am currently performing Large Eddy Simulation of thermal mixing of fluid flows in a T junction piping system. I am a litte bit confused as to what boundary should I give for my solid region present at the hot and cold inlets of piping system(See the figures attached). Since the solid and the fluid regions are continuous and not exposed to atmosphere, what would be the suitable boundary condition for the solid region present at the inlet? It may sound like a basic question, but I am a bit confused in which boundary conditions to apply and any help in making my understanding of the concepts better would be appreciated. Thank you.

Regards,
Karthick

You should match whatever you are modelling. If it goes to a big block of material which is at constant temeprature then use a constant temperature. If it is a convective boundary with air then use that. If it has no heat transfer use adiabatic.