Effect of Electric permittivity and Ionic mobility on Electro-Soluto-Convection within Two Stacked Layers of Miscible Dielectric Liquids Induced by Unipolar Injection

This work deals with the mixing of two miscible dielectric liquids enhanced by electro-convection mean. We have improved the numerical model presented in the previous ICDL conference in 2022. This model can now account for the case where the two liquids in presence have different permittivities and ionic mobilities. It appears that the permittivity ratio has a direct impact on the flow dynamics. According to he permittivity ratio, the ripples that we have highlighted in the early growth of instability have an increased amplitude and may last longer before electro-convection takes place. For a given electric Rayleigh number T and for small values of this permittivity ratio, it is even noticed that the growing instability suddenly decreases before the flow returns to rest, although for the same T but with permittivity ratio higher, electro-convection takes place. When permittivity ratio or ionic mobility ratio are increased, we have observed that the electro-convection strength is higher.