Numerical simulation of double diffusive convection in a V-shaped sump

The numerical simulation of double diffusive convection in aV-shaped sump is investigated in this paper. The linear variations of temperature and concentration on the wall of the V-shaped sump are considered to simulate approximately the boundary condition of the liquid region during continuous casting. Solutions are obtained by solving the conservation equations of mass, momentum, energy, and concentration in the boundary-fitted coordinate system. A nonuniform grid is used in the computations. Pure thermal convection and pure solutal convection for the same boundary conditions as double diffusive convection have been analyzed first to explore the flow phenomena by thermal buoyancy force or solutal buoyancy force alone. The double diffusive convection at different buoyancy forces ratios is then investigated. The flow pattern that appeared in the cross section is discussed in detail. It was found that the double diffusive convection flow in they-shaped sump is dominated by solutal convection, which is characterized by a multilayered flow structure when the buoyancy forces ratio is greater than 10. However, the thermal convection flow prevails on the flow when the buoyancy forces ratio is less than 1. Furthermore, the double diffusive flow in the V-shaped sump becomes weaker as the angle of the V-shape sump decreases. In addition, the effects of Lewis number on the flow pattern are discussed.