Detailed simulation of nitrogen dissociation over a sphere

Charles H. Campbell, Graham V. Candler

Research output: Contribution to conferencePaperpeer-review


The coupling between a molecule's vibrational state and its dissociation rate is one of, the most important and poorly understood processes in hypersonic flows. The details of this process affect a vehicle's aerodynamics and thermal protection requirements. It also has a direct effect on the level of ionization in the flow field. In this paper, we examine the vibrational relaxation and dissociation process in the forebody region of a 10 cm sphere. We simulate the vibrational exchange mechanisms using the forced-harmonic oscillator and Schwartz-Slawsky-Herzfeld vibrational relaxation models where resonant vibration-vibration exchange is included. A classical impulse' dissociation model simulates the N2-N2 and N2-N dissociation processes. It is found that highly non-Boltzmann vibrational distributions are present along the entire stagnation line which can not be captured by a conventional single-vibrational temperature model. In addition, it is found that mass diffusion significantly effects vibrational distributions and atomic Nitrogen mass fractions.

Original languageEnglish (US)
StatePublished - 2000
Event38th Aerospace Sciences Meeting and Exhibit 2000 - Reno, NV, United States
Duration: Jan 10 2000Jan 13 2000


Other38th Aerospace Sciences Meeting and Exhibit 2000
Country/TerritoryUnited States
CityReno, NV


Dive into the research topics of 'Detailed simulation of nitrogen dissociation over a sphere'. Together they form a unique fingerprint.

Cite this