Water-vortex stabilized electric arc: I. Numerical model

A numerical model for an electric are stabilized by a water vortex has been proposed. The two-dimensional axisymmetric model includes the discharge area between the cathode and the orifice of the are chamber. The production of water plasma, i.e. the rate of evaporation of a water wall, is taken either from experiments or is determined numerically by fitting of the outlet plasma parameters to the experimental ones. The computer results concern thermal, fluid dynamic and electrical characteristics of such arcs for the currents 300, 400, 500 and 600 A. It is found, for example, that the role of thermal diffusion within the discharge increases with current. The power losses from the are due to radial conduction and radiation represent around 50% of the input power. Rotation of the plasma column due to the induced tangential velocity component has negligible effect on the overall are performance. The calculated velocities, pressure drops and electrical potentials are in good agreement with experiments carried out on the water plasma torch PAL-160 operating at our Institute.