Finite Element Method Analysis of an Electric Field in Wire-Cylinder Electrode Configuration during Corona Discharge K. KANTOUNA L. EKONOMOU G.P. FOTIS G.E. CHATZARAKIS kkantouna@hotmail.com leekonom@gmail.com gfotis@gmail.com gea.xatz@aspete.gr ASPETE - School of Pedagogical and Technological Education Department of Electrical Engineering Educators N. Heraklion, 141 21 Athens, Greece Abstract: For about a century it has been known that an electro-hydrodynamic effect results when high voltage is applied to a set of electrodes with asymmetric configuration. The electro-hydrodynamic effect which is widely known as “ionic wind”, takes place in the area between an emitter and a collector electrode under high voltage dc application. This effect has many research and industrial applications such as electrostatic precipitation, ozone generators, electrostatic painting and generally applications where small particle or droplet motion control is needed. In this work a theoretical and numerical investigation of electric field distribution and electro-hydrodynamic flow of air at wire - cylinder electrode configuration has been carried out. Field and flow patterns have been visualized by the use of dedicated software based on finite element method and the results were evaluated. Key-Words: Corona discharge, Electro-hydrodynamic effect (EHD), Electric Field, Finite element method (FEM), High voltage, Electrode configuration 1. Introduction Corona discharge is the effect, which takes place between an emitter and a collector electrode, under high voltage dc application. This effect occurs in the dielectric medium at the space between the electrodes and refers to the transfer of momentum from moving ions accelerated by the electric field to the neutral air molecules located along the path of the ionic flow. Ions convert the potential energy to motion and as the potential and the field intensity increase, the ion velocities are increasing too. When the electric field strength is approaching 30kV/cm and above, ionic saturation is observed in the path. Then the insulating material becomes conducting and a glow can be observed. Yabe et al. [1] were among the first to investigate the EHD flow produced by the corona discharge in a 2-D electrode arrangement of a wire-plate system. Recently Atten et al. [2] concluded that the total corona current differs only slightly for small corona currents (below 6 kV). Buehler [3] said that the resulting force seems to be proportional to the amount of electrical potential energy stored in the electrostatic field. The net result is the production of a flow without any moving parts, characterized by low power consumption. Adamiak and Atten [4] proposed a numerical technique by determining the distributions of electric field and charge density in the case of a positive corona discharge in gas in the point–plane geometry. Zhao and Adamiak [5] were able to explain the mechanism responsible for generating thrust by investigating the corona discharge and the secondary electro-hydrodynamic flow in a system consisted of two mechanically connected electrodes, a thin corona wire that is parallel to a thick ground electrode without any sharp points. Dumitrana et al. [6], in their first study presented a simple numerical method that had been proposed to calculate the spatial distributions of electric field and ionic space charge in a case of a continuum and uniform corona discharge originating at the surface of the wire. In another study, Dumitrana et al. [7] analyzed the numerical computation of the electric field strength and ionic space charge density in an electrode system. Another numerical model for the electric field and gas flow in a wire-plate electrostatic precipitator with a single corona wire was presented by Zhao et al. [8]. The electrical conditions in the precipitator channel were simulated by solving a full two- dimensional single-species model of the electric corona discharge. Podlinski et al. [9] in their experimental results showed that when the EHD Latest Advances in Systems Science and Computational Intelligence ISBN: 978-1-61804-094-7 97