Negative corona in air at atmospheric pressure due to a voltage impulse

Abstract

This article presents a numerical modeling of a negative corona caused by an overvoltage pulse (∼250%), in a point-to-plane electrode system. The field value applied to the cathode is high, thus, the numerical simulation described in this article attempts to show that the field-effect emission can be responsible for the ignition of the corona and for its first stage of development, while the positive-ion bombardment is responsible for sustaining the discharge during the current decay phase. A time-dependent enhancement factor is introduced in the classical Fowler–Nordheim relationship in order to model the switch on of some emissive site at the cathode surface. Preliminary experiments were carried out in order to better understand the ignition and development of the corona. The role of the field-effect emission is underlined and the dimension of the corona is optically determined. The negative corona current pulse and its associated emitted UV light are computed and compared to experimental results.

Effect of humidity on negative corona discharge of electrostatic precipitators

“…The model for calculating the corona of the ESP was based on the streamer theory [18][19][20][21]. A primary avalanche was formed when the electric field in the vicinity of the corona wire reached the onset value of gas ionization by electron collision.…”

“…This could possibly be provided by photoemission, positive ion impact, metastable action or field emission [18][19][20][21]. Field emission was possible only at an electric field over 5×10 7 V/m.…”

Electric wind characterisation in negative point-to-plane corona discharges in air

“…Because of the geometric effect and the local presence of the cloud, the electric field between electrodes is strongly nonuniform and varies with time as successive clouds drift from one electrode to the other. This phenomenon gives a pulsating electric current in the external circuit [3,8,[13][14][15] and causes an electric wind flowing from the point toward the plane [9][10][11][12][16][17][18].…”

“…Various aspects of corona discharges in atmospheric air have been extensively studied both experimentally and theoretically [1][2][3][4][5][6][7][8]. However, the gas flow between pointto-plane electrodes has not yet been investigated in detail.…”

FE Analysis of Plasma Discharge and Sheath Characterization in Dry Etching Reactor

“…The most frequently used algorithms are the hydrodynamic diffusion-drift model incorporating flux-corrected-transport (FCT) method and particle-in-cell (PIC) method [2][3][4][5][6]. In this paper, we proposed a full finite element approach where the charge transport equations of hydrodynamic diffusion-drift model and the electric field equation were numerically solved in a fully coupled system by using a standard finite element procedure for transient analysis [7][8][9][10][11].…”