STUDY OF FREE BURNING ARC CHARACTERISTICS BY DIMENSIONAL ANALYSIS AND COMPUTER SIMULATION

摘要

This paper deals with the study of experimental current intensity/voltage characteristics of a free burning arc that appears to be singular: At low intensity current, the arc voltage decreases until a minimum value, corresponding to a critical current intensity IC. For current intensities higher than IC, there is an increase of the arc voltage with the current intensity. Dimensional analysis and Pi theorem coupled with a large set of experimental data allow us to evaluate the main physical processes responsible for the characteristics shape. At low current intensity, the plasma is mostly driven by thermal conduction effects while at high current intensity, it is principally governed by radiation losses. Finally, the results obtained from dimensional analysis allow to propose a ID numerical simulation of the plasma column that gives rather good qualitative results.