MEAN FLOW EFFECTS IN THE ELECTROHYDRODYNAMIC CONVECTION IN NEMATIC LIQUID-CRYSTALS

On the basis of the weakly nonlinear analysis a set of two coupled amplitude equations is derived, which lead to a better understanding of the electro-hydrodynamic instability in nematic liquid crystals near onset. It is shown that the normal convective patterns are very sensitive against large scale flow (mean flow) modes, which are systematically included. Simulation of the equations shows typically a complex spatio-temporal behavior ("defect turbulence") very similar to the situation often observed in experiments.