Two-dimensional model for spark discharge simulation in air

A two-dimensional model simulating the hydrodynamic behavior of the plasma produced by an ultrafast pinto-pin electrical spark discharge in air is presented, The plasma is considered to behave like nonviscous, single-substance, nonpolar, heat-conducting fluid. It is assumed that local thermodynamic equilibrium prevails within the domain of calculation. The energy input is determined by a prescribed electric current, coupled with a computation of plasma conductivity, Radiative losses from the domain also are considered. The model employs an equation of state for air that includes the effects of vibration, ionization, and dissociation energies at high temperature, Governing equations are solved numerically using the MacCormack time-splitting technique. An explicit artificial viscosity term is introduced into the equations, and flux-corrected transport is used as a postshock oscillation damper. The results show that the hydrodynamic effects and electrode geometry are responsible for the formation of a torus-like plasma kernel.