Computational fluid dynamics analysis of diffuse vacuum arcs

A two-dimensional axi-symmetric numerical model is developed in order to understand the characteristics of diffused vacuum arc. Vacuum arcs mainly consist of metal vapors which are generated by local evaporation of the contact material due to higher current densities. Strong coupling and high gradients between many parameters like, current densities, temperatures, electrical conductivity, magnetic field and high velocities of plasmas pose many challenges in modeling vacuum arcs. Present work consists of solution of two-fluid equations for electrons and ions. In addition to fluid equations, Maxwell´s equations are solved to obtain the Lorentz force and Joule heat which are implemented as source to momentum and energy equations respectively. Simulation results show the variation of the ion and electron number densities, their temperatures, velocities and magnetic flux.