I am doing Thermal radiation analysis of a furnace.Here inside the furnace 5 concentric rad shields are placed.Furnace is vacuum condition.These rad shields are surrounded by thick round wall.I want to find the temperature of each rad shield.

I give input as in image 3..

Since am interested in finding out the temp of only rad shields,am not using that outer wall..

Inside temp 1100K

Emissivity 0.56

Heat generated inside 60kw..

With these inputs,when run it gives error saying "Inadequate boundary conditions" analysis failed..What other inputs reqd?