SIMULATIONS OF OSCILLATORY ELECTROCONVECTION IN A HORIZONTAL CAPACITOR WITH A LARGE ASPECT RATIO

The behaviour of a low conducting fluid in a cell with a large aspect ratio subject to a transverse electric field is studied, with injection and dissociation mechanisms of the charge formation. The time evolution of the stream function maximum, the characteristic spatial scale of structures and the characteristic frequency of oscillations are found for electroconvective flows. Near the instability threshold, the main frequency of the stream function oscillations at a fixed point of the capacitor coincides with the frequency of neutral oscillations. It is found that the interaction of different lateral harmonics generates an amplitude-modulated traveling wave. The intensity of convective vortices in the traveling wave varies along the horizontal axis. It is shown that with increasing super criticality (electroconvective parameter) the traveling wave pattern becomes complicated due to the growth of the number of spatial harmonics.