Time depending behavior in finite amplitude electroconvection

Ion transport and mixing in periodic finite-amplitude electroconvection are studied. It is shown that ion trajectories in EHD (electrohydrodynamic) convection become chaotic when the velocity field is periodic. The separatrix gives place to an homoclinic tangle and a chaotic layer, the latter comprising a finite region of both injector and collector electrodes. For large enough values of the amplitude perturbation this resonance separatrix layer connects the inner and outer regions, thus allowing the ions to enter the otherwise empty-of-charge region. It is conjectured that this chaotic nature of ion trajectories is at the basis of the chaotic behavior of EHD flows