Computation of turbulent natural convection with buoyancy corrected second moment closure models

For the numerical analysis it has been reported that the Eddy Viscosity Model (EVM) or Eddy Diffusivity Model (EDM) fail to simulate those complicate phenomena (reference). Therefore, it is plausible option to adopt the Second Moment Closure (SMC) models for both Reynolds stress and turbulent heat flux (which is called "buoyancy corrected" in this study) to simulate the turbulent natural convection phenomena. Therefore, in this paper, the model validation to examine the major phenomena of the turbulent natural convection such as stratification, transition along the vertical wall and an anisotropy behavior near wall are performed with selected models. For the molten pool which has the low Prandtl number, it is simulated to analyze the fluid Prandtl number effect on the thermal behavior of the reactor case. Turbulent natural convection is a key phenomenon to understand thermal behavior of the oxide molten pool, including stratification, laminar to turbulence transition and anisotropic behavior near wall. In this work, the buoyancy corrected SMC model was implemented in OpenFOAM and validated with experiments. The selected models well simulate the characteristics of natural convection and the anisotropic behavior in the vicinity of the wall reproduced properly by buoyancy corrected models.