Seyfolah Saedodin, M.S. Motaghedi Barforoush, Mohsen Torabi

Frontiers in Heat and Mass Transfer (FHMT) 2 - 044001 (2011)

Radiation is one of the most important modes of heat transfer. In this paper, a simplifying approach for calculating the radiant energy is achieved using the concept of net radiation heat transfer and provides an easy way for solving a variety of situations. This method has been applied to calculate the net radiation heat transfer between two long concentric semi-cylinders. Then this method used to calculate reduction heat transfer when radiation shields with temperature-dependent emissivity applied between these objects. Moreover, using this method the percentage reduction in heat transfer between two surfaces was calculated. The findings reveal that, one radiation shield with lower emissivity can reduce the net heat transfer even better than two radiation shields with higher emissivity. Moreover, it can be concluded that for silicon carbide radiation shield in the range of assumed temperatures, the emissivity is almost constant.