Water-vortex stabilized electric arc: I. Numerical model

Abstract

A numerical model for an electric arc 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 arc 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 arc 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 arc 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.

Numerical Investigation of Hybrid-Stabilized Argon-Water Electric Arc Used for Biomass Gasification

“…In experiment, velocity at the nozzle exit is being determined from the measured temperature profile and power balance assuming local thermodynamic euilibrium . First, the Mach number M is obtained from the simplified energy equation integrated through the discharge volume (Jeništa, 1999b); second, the velocity profile is derived from the measured temperature profile using the definition of the Mach number regime (i.e., the mean value of the Mach number over the nozzle exit higher than 1) using this method was proved for 500 A and 40 slm of argon, as well as for 600 A for argon mass flow rates higher than 27.5 slm. Similar results have been also reported in our previous work (Jeništa et al, 2008).…”

The Influence of Turbulence on Characteristics of a Hybrid-Stabilized Argon-Water Electric Arc

“…( [23][24] These were solved by the SIMPLER iteration procedure (25) which enables calculation of w for the axisymmetric case, i.e., w is a function of r and z coordinates. The w velocity acts here only through the centrifugal force 2 w r ρ in the radial momentum equation.…”

“…The w velocity acts here only through the centrifugal force 2 w r ρ in the radial momentum equation. The influence of the tangential velocity component w on the overall arc performance was studied in greater detail in our previous papers (23)(24) but it was found that its effect on the arc performance is small. In fact, the maximum difference in the outlet parameters was less than 2% regarding the case which excludes the tangential velocity component.…”

Steam Plasma Flows Generated in Gerdien Arc: Environment for Energy Gas Production from Organics and for Surface Coatings

“…Complex experimental data about properties of the arc and parameters of generated plasma were presented in [8][9][10][11], two-dimensional numerical model of Gerdien arc was formulated in [12,13].…”