Experimental and numerical study of metal droplet splashing effects on direct current air arc interruption

To investigate the interaction between metal droplet motion and arc plasma dynamics during direct current interruption, an improved bidirectionally coupled model is developed based on magnetohydrodynamic theory. By incorporating the volume force exerted by the metal droplet into the momentum conservation equation, the model enables dynamic feedback between the air arc flow field and the metal droplet trajectories. The influence of droplet splashing (DS)-under varying velocities and particle sizes-on the flow field distribution within the contact gap is analyzed, and the mechanism of flow field reconstruction induced by metal droplet motion is revealed. Simulation and experimental results demonstrate that DS typically occurs under conditions such as current oscillation, which induces localized vortices in the flow field and inhibits the directional motion of the arc. Furthermore, metal droplets with larger diameters and higher velocities cause more severe disturbances to the arc-induced flow field.