Simple Radiation
 

Hallo Everybody
here is a simple model for CFX simulating simple radiation:
There is a closed volume with air ideal gas, and one of the bonduary walls
has fixed temperature at 900K
I expect the solution show the gas pressure increase with time,

There is no buoyant model because I don't what the contribution of
the convective term.

If you see the results there is no variaton of pressure.....
Can someone give me any advice ?