Numerical Simulation of Natural Convection Phenomena

Abstract

Natural convection heat transfer associated to fluid-dynamics phenomena has been extensively studied in many applications of scientific and industrial areas. Numerous benchmarks provide numerical and experimental data of these phenomena in a wide range of Rayleigh (Ra) numbers.
Three dimensional high Ra number regimes are particularly challenging to simulate due to instabilites sensitivity, need of correction of turbulence modeling and so on. The literature on this topic is scarce. In this paper Fluent and OpenFOAM codes have been used to assess the Boussinesq approximation for a wide range of Ra numbers (10*3 - 10*8) for two dimensional (square cavity) and three dimensional (cubic cavity) cases. High Ra number cases are particularly discussed showing model limitations and code capabilities to cope the natural convection phenomena. Results are compared with classical benchmark cases available in the literature, finding excellent agreement with both experimental and numerical data.
Underlying theoretical models and implementantion are explained in depth, particularly for OpenFOAM code serving as a reference.