Magnetohydrodynamic simulation of DC arc plasma under AC magnetic field

Abstract

Direct current (DC) thermal plasma, shape controlled by use of alternative current (AC) magnetic field enables the wide area of thermal treatment and has potentials of applications other than welding. In this paper, the behavior of DC plasma under AC magnetic field imposed perpendicular to the plasma current is discussed experimentally and theoretically by changing various parameters such as plasma electric current, nozzle diameter, argon flow rate and magnetic flux density including its wave form. As the theoretical study, DC plasma was mathematically modeled by use of three dimensional magnetohydrodynamics (MHD) theory and discussed through numerical simulations performed by full finite volume method approach. Then the DC arc plasma motion under sinusoidal AC magnetic field is discussed through MHD analysis. By these experimental and theoretical investigations, the controlling parameters of DC plasma by AC magnetic field have been made clear quantitatively. © 2005 ISIJ.