Charge density distribution in electrohydrodynamics of insulating liquids

The problem of the charge distribution in the finite-amplitude electroconvection of a layer of insulating liquid subjected to unipolar injection has been solved by a particle-type method, both in the weak and strong injection regimes. A close link has been found between the fact that finite-amplitude electroconvection is time dependent and the existence of a small fluctuating amount of residual charge in regions of the convective cells that would otherwise be almost empty of charge. An accurate calculation of the electric field, including the coulomb repulsion between the injected charge carriers, has proven to be essential for the obtaining of these results.