Boundary for cooling - chtMultiRegionFoam
 

Hello,

I want to simulate a the cooling of a hot pebble bed in a cold airflow with the transient solver chtMultiRegionFoam. The pebbles are in a cylindrical channel, which you can see in the picture.
Attachment 28232

Im not sure what are the correct boundary conditions for the heat transfer between the pebble bed and the fluid (air). In the beginning the pebble bed should have a temperature of 500K. The cold airflow (300K) should be heated up by the pebbles, while the pebbles are cooled.

I use the boundary condition which is also used in the MultiReginHeater tutorial of chtMultiRegionFoam. I added the boundary conditions for T:
Attachment 28234
Attachment 28235


Is this the correct heat exchange Model?


Thanks in advance.
Andreas