Numerical Study of Electro-thermo-convection in a Differentially Heated Cavity Filled with a Dielectric Liquid Subjected to Partial Unipolar Injection

The Coulomb force applied by an electric field on any charge present in a dielectric liquid may cause fluid motion. At high applied electric fields in an insulating liquid, electric charge carriers are created at metallic/liquid interfaces, a process referred to as ion injection, and result from electrochemical reactions. In this article we deals with the problem of electro thermal convection in a dielectric liquid placed in a square cavity and subjected to the simultaneous action of a thermal gradient and an electric field. Thus the aim is to analyze, from a numerical point of view, the evolution of flow structure, charge distribution and heat transfer for the case of a strong injection. The studied configuration is the following: the vertical walls were differentially heated; the horizontal walls adiabatic and only part of the bottom wall (33% of the total length) contributes to the charge injection. Three possible configurations are treated depending on the position of the injection zone: so we identify an injection from the left, the middle and finally the right.