Large-eddy simulation of combined forced and natural convection in a vertical plane channel

A combined forced and natural convective flow between two vertical plates with different temperatures is studied using large eddy simulation. The numerical simulations were performed with a Grashof number of Gr = 9.6 × 105 and Reynolds number of Reτ = 150 (based on the wall friction velocity and half channel width). Two sets of dynamic subgrid-scale (SGS) models were tested in the simulation; namely, the set of linear SGS models consisting of the dynamic Smagorinsky SGS stress model (DM) and dynamic eddy diffusivity SGS heat flux model (DEDM-HF), and the set of nonlinear SGS models consisting of the dynamic nonlinear SGS stress model (DNM) and dynamic tensor diffusivity SGS heat flux model (DTDM-HF). The numerical results are compared with the reported direct numerical simulation data. It is found that the resolved and SGS quantities related to the temperature field are noticeably influenced by the choice of SGS models. In general, the set of dynamic nonlinear SGS models yields better prediction of the flow than the set of dynamic linear SGS models.