Recent Progress in our Understanding of The Physical Processes in Arcs in Gas Flow

The conditions under which similarity and sealing laws exist are investigated. A quantitative analysis of the on-set of arc instability is given and the destabilizing mechanisms are identified. The existence of shock in some arc devices seriously disturbs the flow although the electric characteristics of the arc are little affected. Finally, computer simulation results of the operation of a complex industrial device, a high voltage auto-expansion circuit breaker, are given. (author)