The effects of metal vapour on the fault arc in a closed, air-filled container

The present work is an investigation of the effects of metal vapour on the behavior of a fault arc in a closed, air-filled container. Experiments were performed to measure the pressure, temperature, and energy balance of the fault arc for different metal electrodes. Theoretical results are obtained using a magneto-hydrodynamic model for the fault arc and then compared with the experimental results. It is found that the effects of increased radiation and mass transfer caused by metal vapour considerably cool down the plasma in the central arc, whereas the influence of increased electrical conductivity is relatively small. The simulation of the energy balance suggests that the pressure rise is seriously affected by the metal vapour due to the similarity of heat transport processes of the fault arc. In the case of Cu and Al electrodes, the heating of surrounding gas dominates in the energy dissipation, while for Fe, the radiation does. Huge chemical energy released due to Al vapour results in the maximum pressure rise for Al electrodes, and the strong radiation in the case of Fe electrodes is responsible for its smallest pressure rise.