Flow Structure Near Downstream Electrode of a Gas-Blast Circuit Breaker

Flow structure near the downstream electrode, located in the supersonic region of a gas-blast circuit breaker interrupter, has been investigated. In the absence of the arc, a bow shock is formed in front of the tip of the downstream electrode. The presence of a 1-kA dc arc renders the flow in front of the electrode tip subsonic. The compression waves associated with the formation of flow stagnation point in the vicinity of the electrode tip are bunched together on the arc axis, forming a pressure distribution similar to a shock.