[sorkhani]

hi, i want to model a furnace and a solid(has diameter and it's inlet temperature is fixed) in bottom of it.
in the interface of fluid(furnace) and solid,i used coupled BC. but heat transfer in solid(upper side and down side ) is not good and these surfaces
have almost equal temperature.
k for solid is 31.
radiation model is p1 and abs. coeff. is 0.2
source term in fluid(furnace) is 150
temperature of solid left wall is 1000k
all walls (except solid left wall) are adiabatic.

what's the solution? plz, help me !!

Tout
--------------
*
furnace *
*
--------------
solid *
--------------
adiabatic BC.