Simulations of double-diffusive convection in narrow containers

Abstract

A numerical investigation was conducted on the evolution of double-diffusive layers in a narrow-aspect-ratio cylinder that contains a salt-stratified fluid and subjected to bottom and side-wall heating. The numerical results were compared with the data of a laboratory experimental study conducted in parallel. The simulations were carried out using the Fluent computational fluid dynamics code, with a modified shear-stress k–ω transport model to better account for buoyancy effects. The role of the turbulence model in numerical predictions was investigated by conducting laminar and turbulent flow simulations. Both the experimental and numerical results show formation of multiple mixed layers of fluid separated by diffusive interfaces. Comparisons of laboratory and numerical results show a very good agreement for the layer thicknesses and not such good agreement for the temperature and salinity structures. The reasons for disparities between the model and experimental results were identified.