Study on the Effect of Metal Droplet Splashing on the Breaking Characteristics of DC Air Arc

When the air circuit breaker is broken, in the process of the arc root transition to the grid, there will be a long time of stiction at the edge of the contact, and metal droplets will be splashed which has an important impact on the breaking ability of the air circuit breaker. In this work, considering the coupling relationship between the motion equation of metal droplets and the momentum conservation equation and energy conservation equation of air arc. The bidirectional coupling model of metal droplets and air arc is proposed for the first time and solved. The model is an improvement on the traditional MHD model, considering the volume force exerted by metal droplets on the air arc flow field. The results show that the metal droplet splashing can change the air arc flow field distribution, slow down the cathode arc root movement, prolong the arc stagnation time, and lead to more serious ablation.