Natural convection in an enclosure with uniform heat generation and isothermal sidewalls is studied here. The natural convection in heat generating fluid volumes is sensitive to nature of fluid, extent of heat generation, type of boundary conditions and nature of boundary geometry. This paper presents numerical investigation of natural convection in a square cavity with volumetric heat generation and with varying sidewall temperatures for Prandtl number of 0.7 and 5.85. We observe the structural change of the convection pattern depends on the relative magnitudes of internal and external Rayleigh numbers and value of Prandtl number. The studies will act as a basic understanding of convection in in-vessel molten corium pool during a severe accident scenario of a light water reactor.

Keywords: Natural convection, Volumetric heat generation, Corium melt-pool.