Heat transfer performance of downward-facing carbon and stainless steel surfaces

Heat transfer performance of downward-facing flat heaters is summarized in this paper. The combined effects of material, orientation, dimension and pressure are considered. According to the overall trends, the results show complicated tendencies in which the parameters are interrelated. With the heat transfer characteristics, some CHF trends that have been observed in previous studies are analyzed. Some transitional phenomena occur with orientation, and a related analysis is conducted using a dry-spot concept. Various environments like pressurized conditions are considered in this study, including real accidental conditions. For the material effect, a real material, carbon steel, used for the severe accident mitigation strategies is considered. The overall heat transfer performance at the most critical locations of the severe accident strategies can be extracted from the results.