MODELLING THE CHARACTERISTICS OF CONSTRICTED-ARC PLASMA IN STRAIGHT AND REVERSE POLARITY AIR-PLASMA CUTTING

摘要

The paper deals with the issues of mathematical modelling of turbulent flow of electric arc plasma in straight and reverse polarity plasma cutting. It is noted that the main complexity of modelling reverse polarity cutting arises at description of plasma flow in near-electrode regions. In view of that, it is proposed to describe arc electromagnetic characteristics in the cut cavity proceeding from the known experimental data. Detailed comparative analysis of the influence of plasmatron operating modes and arc polarity on arc discharge electric characteristics, thermal and gas-dynamic characteristics of the plasma flow is performed on the base of numerical modelling.