Penalty upwind finite element method for diffusive convection problem in double-diffusive system

The penalty function upwind finite element method was described in this paper for the diffusive convection problem in temperature and salinity double diffusive system. With good stability and two-order accuracy, the method was directly employed to original equations, and tested in a square cavity with constant lateral heating. Numerical simulation was achieved with distribution of stream function, temperature and concentration isocontours under thermal Raleigh number Re=106 and the thermal buoyancy ratio covering the range of N=1, 3, 5, 7. Meanwhile, the effects of N and the adiabatic baffle to the fluid field were also discussed.