Internal Emissivity boundary condition
 

Hi all, I am trying to simulate coal combustion in power boiler together with heat transfer through solid to water tube behind mentioned wall. Could some help me to set the correct boundary conditions for wall dividing flue gases and water volumes. What type of heat transer conditions are to be set- radiation, convection, mixed, etc. And what estimated value of internal emission factor should I start with? And the second thing- what is the physical meaning of the condition "internal emission"? Can you translate it for me to "human".

Thanks in advance and forget my english.

Piastun

I am recycling this message since I am having a very similar problem. Could anyone please help me to understand better the meaning of internal emissivity? (is that like how much energy would be absorbed by the walls?) I am slightly confused between this one and external emissivity.