Large-Eddy Simulation of Turbulent Rayleigh-Bénard Convection: An Assessment of Subgrid-Scale Models

Large eddy simulation of turbulent Rayleigh-Bénard convection was carried out to assess various algebraic viscosity subgrid-scale models: (i) Smagorinsky with Wall-Damping, (ii) Dynamic Smagorinsky, (iii) Wall-Adapting Local Eddy-Viscosity, (iv) Vreman, (v) Mixed-Scale, and (vi) a buoyancy-modified Mixed-Scale model that accounts for the buoyancy effects from subgrid-scales. The last is proposed first time in this study. Non-dissipative, kinetic energy conserving, fully implicit method employed simulations. To evaluate models, mean (both low- high-order) flow diagnostics were computed. Some advanced statistics such as skewness, heat flux, Nusselt number also calculated compared each other against reference solution. Since models differ by means generation terms, they have their own strengths weaknesses which are particularly observed near-wall treatments. Additionally, unlike others, computes coefficient dynamically has some on results. Overall, its new, variant show different characteristics mostly best agreement Direct Numerical Simulation data. They found computationally less expensive. Moreover, enhancement new slightly improves predictions model. Although relatively poor performance especially estimating integrated number, it captures flux more accurately than others. A detailed discussion model's based evaluations made.