Wave Profile for Current Bearing Lightning Strokes

Abstract

The propagation of breakdown waves in a gas, which is primarily driven by electron gas pressure, is described by a one-dimensional, steady-state, threecomponent (electrons, ions, and neutral particles) fluid model. This study will involve waves propagating in the opposite direction of the electric field force on electrons (anti-force waves—lightning return stroke) only. We consider the electron gas partial pressure to be much larger than that of the other species and the waves to have a shock front. Our set of equations consists of the equations of conservation of the flux of mass, momentum, and energy coupled with the Poisson’s equation. The set of equations is referred to as the electron fluid dynamical equations. For breakdown waves with a significant current behind the shock front, the set of electron fluid dynamical equations and also the boundary condition on electron temperature need to be modified. For a range of experimentally measured current values and a range of possible wave speeds, we will present the method of solution of the set of electron fluid dynamical equations and also the wave profile for electric field, electron velocity, electron temperature, and number density, as well as the ionization rate within the dynamical transition region of the wave.