Electro-Convection in Cells with Plane and Wire Electrodes

An experimental and theoretical study has been made of the induced electro-convection of a dielectric oil in glass cells fitted with parallel plane and wire electrodes. From laser doppler anemometer measurements it was found that the steady, well-defined vortex patterns existed in the cells only for a limited period from initial excitation, and that subsequently the motion became less ordered. Flow visualization and streakline photography confirmed that this unsteadiness was due to the bulk movement of the vortices. An explanation of the bulk movement is offered based on the concept of vortex interaction, the theoretical analysis showing good qualitative agreement with experimental observations of a confined vortex pair.