Radiation modeling
 

Hello everyone,

I am studying the effect of surface radiation on mixed convection heat transfer through a vertical annulus of two concentric cylinders with inner cylinder uniformly heated and outer cylinder adiabatic. I have completed the mixed convection part and is working currently on radiation....I need to study the heat transfer across the annular gap only, for which i have modeled only the annular gap region of the vertical annulus. When radiation was incorporated, i have found that the temperature inside the inner cylinder(which i have not modeled) increases. This is not i needed.. I want the heat transfer to occur only inside the annular gap and not outside the model.....Hope you have understood my problem.....What sholud be done? Somebody please help me....Please....
Thanks......