Pattern formation in EHC of planar nematic layer with cylindrical directorfield configuration

Pattern formation in planar nematic with cylindrical director field configu ration in the conductive regime of electrohydrodynamic convection has been studied experimentally. The rotating roll pattern with axial symmetry has b een found above the threshold. For frequency of ac electric field lower tha n the Lifshitz point, the roll pattern is divided into two systems of rotat ing oblique rolls so that their superposition looks like sunflower. The rot ation frequency of rolls has been measured as a function of ac electric fie ld frequency.