Numerical simulation of a constant current density discharge in a flowing air plasma

Computational fluid dynamics is used to simulate a series of nonequilibrium plasma experiments being performed at Stanford University. In these experiments, a controlled constant current density discharge is applied to a low temperature, atmosphere pressure flowing air plasma. Measurements of temperature, electric field and electron concentration are made. The computational model includes a 1 l-species, 41-reaction finite-rate chemical kinetics model for the plasma. It uses finite rate models for vibration-electronic energy relaxation and electron translational energy relaxation. The influence of the current density on the electron number density is studied. The simulations show that it is possible to sustain low temperature (~ 3000K) air plasmas with electron concentrations above 10¹³ cm^-3 by using pre-ionized process gases with sufficiently high electron densities.