Influence of Skin Depth on Convective Heat Transfer in Induction Heating

Abstract

We investigate convection driven by induction heating of a horizontal fluid layer with direct numerical simulations (DNS). This problem is of particular interest in the context of nuclear severe accident mastering. In a real severe accident, the molten core is subjected to homogeneous internal sources resulting from nuclear disintegrations. This situation is mimicked in the laboratory using induction heating as the internal source. In induction heating however, heat sources are localized in the skin layer. Consequently, this concentration of heat may modify the flow and wall heat transfer, compared to the case of homogeneous internal sources. DNS are carried out for three typical skin depths and three total deposited powers. Skin depth variations show surprising results regarding flow structures and heat transfer. It is found that the heat sources heterogeneity has a weak effect on flow structures. Consequently, models of heat transfer in the case of homogeneous sources remain valid even with strong localized heating near the bottom.