Numerical simulation of a nonequilibrium nitrogen plasma experiment

Computational fluid dynamics is used to simulate recent nonequilibrium plasma experiments performed at Stanford University. In these experiments, a high temperature nitrogen-hydrogen-argon plasma is generated and then forced to cool under controlled conditions in a test-section. Measurements of temperature and electron concentration are made at three locations. The computational model includes a 14-reaction finite-rate chemical kinetics model and a finite-rate vibration-electronic energy relaxation model. Two models are used to compute the mixture transport properties. The simulations do not agree with the experiments; the centerline plasma cooling rate is under predicted, resulting in the electron concentration remaining too large. Possible reasons for this difference are discussed.