Quasi-Equilibrium Kinetic Model of HF Air Breakdown.

摘要

In Phase I of the program, we developed the basic tools needed to build a high-frequency air breakdown model. We developed a Quasi-Equilibrium Methodology (QEM) for extending fluid electron transport models to the nonequilibrium regime, based on assuming that the transport coefficients relax toward their equilibrium values on time scales quantified by time-dependent Boltzmann equation solutions. Our analysis of nonequilibrium electron transport discovered and explained a velocity overshoot effect that is not generally known. That tendency of the electrons to overshoot the equilibrium drift velocity is shown to have a profound effect on streamer behavior. We examined the extent of possible simplifications to our kinetic air breakdown model, concluding that factors of 2 to 5 speed-up are possible. We have identified the major phenomenological issues in a modeling strategy, and examined nonequilibrium effects on ionization waves. Finally, we present a plan to complete development of a computational model of High Frequency air breakdown suitable for incorporation into EMP coupling codes, including model verification experiments and implementation of the computer module in an existing EMP coupling code. Dielectric breakdown, Kinetics, Boltzmann equation, Non-equilibrium transport, Streamers, Spark, Arc, HF discharge.