Onset of Convection in a Ternary Mixture in a Square Cavity Heated from Above at Various Gravity Levels

Abstract

The influence of a static gravity level on Soret-driven convection of a ternary mixture in a square cavity heated from above is investigated. The problem is solved by the finite difference method using the equations of thermosolutal convection in multicomponent mixtures. These equation are transformed to a set of equations to eliminate the cross-diffusion effects and to reduce the number of governing parameters. Calculations are performed to study a ternary mixture with the components having different signs of the separation ratios at different levels of gravity. Due to the thermodiffusion effect, the component with a negative separation ratio moves to the upper (hot) wall. This leads to the development of instability accompanied by a sharp increase in the flow intensity and a sharp decrease in the concentration difference between the upper and lower boundaries. Numerical data on the time evolution of integral characteristics of flow and heat and mass transfer, and data on the structure fields of stream function and concentration at different times for different values of the Rayleigh number (different levels of gravity) are obtained.