Convective instability near the interface between counter propagating fluxes of inter-soluble liquids

The hydrodynamic process of light liquid displacement by the heavy one in a thin layer of finite length has been investigated theoretically when the initial non-equilibrium distribution of density exists and the effect of miscibility takes place. 3D numerical modeling of convection including the regions with unstable stratification near the interface between counter propagating fluxes of liquids has been carried out. Different quantitative characteristics of the flow are calculated. Namely there are the velocities of concentration fronts in dependence on densities difference. The evolution of convective structures has been simulated at various stages of the process. The results of numerical modeling are consistent with previous experimental data.