Turbulent natural convection with an internal heat source in a semicircular geometry

This paper presents the computational modeling of buoyancy-driven turbulent heat transfer involving spatially uniform volumetric heat sources in a semicircular geometry. The Launder-Sharma low-Reynolds number k- epsilon turbulence model and the SIMPLER computational algorithm which was incorporated into the HITNIS computer code, were used for determining the variations of the thermal-hydraulic variables, including flow patterns and temperature fields, etc. for the modified Rayleigh number of Ra' = 1x10(15). The numerical instability could be minimized by restricting the application range of the near-wall treatment functions of D and E, by adjusting grid size and under-relaxation factors, and by application of a pseudo-transient approach.