Nonequilibrium arc model for the description of arcelectrode interaction

Inhalt:
The arc-electrode interaction is a topic of current interest for switching arc and welding applications. The temperature in/on the electrode is of crucial importance since it controls the rate of erosion and determines the choice of material, dimensions and geometry. The electrodes are heated due to thermal and particle fluxes originating from the plasma and depending on the plasma parameters in the regions close to the electrodes. Therefore, the up-to-date models are aimed at unifying the description of the arc plasma and the electrodes. These models are capable of self-consistent determining the net energy flux toward the electrodes and predicting the temperature distribution. In this work, results concerning the cathode region are obtained by means of two approaches – nonequilibrium modelling of the arc column and the near-cathode region and equilibrium modelling of the arc column combined with nonequilibrium description of the cathode boundary layer. The simulations are presented and discussed for arc currents of 100-200 A.