Hello swathi,

1. I request you to kindly elaborate how the calculated radiation flux values are given as heat input to the system? Is it through a boundary condition at the participating wall (convection heat flux = conduction heat flux + Net radiation heat flux).

2. Or is it also through any volumetric heat source? I guess while using S2S model, the heat input to the system (radiosity values) is not done through any volumetric source terms. 

3. I have this confusion. In all other radiation models, where there is a participating fluid, then there is a meaning of volumetric heat source due to radiation. ( This is true even when there are heat sources in fluid or solid domain.) But when S2S model is used, I dont think there is any contribution from the radiosity values on the volumetric heat sorce due to radiation? Please correct me if I am not understanding S2S model in this regard.