Study of the Influence of Cu Vapour on Air Arc Characteristics

The arc is one kind of mixture plasma containing air and metallic vapour (Cu, Ag, Fe, etc.) in low voltage circuit breaker. The metallic vapour has important influence on arc characteristics because the properties of the mixture plasma are different with the ones of the pure air. The influence of Cu vapour on air arc characteristics is investigated in the paper. Firstly, commercial computational fluid dynamics software FLUENT is adapted and modified to develop the two- dimensional magneto-hydrodynamic (MHD) models of arc with the thermodynamic and transport properties, net emission coefficient for radiation model of 99% Air-1% Cu and pure air, respectively. Then, relevant experiments are carried out to verify the models by measuring the arc motion average velocities with 2-D optical fiber measurement system. It demonstrates that with the influence of Cu vapour, the arc center temperature is lower and the arc motion is slower.