Role of Nonequilibria in Laser Supported Combustion Waves in Nitrogen.
Abstract
The role of nonequilibrium phenomena in the propagation of Laser Supported Combustion waves in nitrogen was examined from a variety of viewpoints. Graphical techniques and criteria were developed and applied over a wide range of laser power levels to assess the role and importance of possible non-Maxwellian electron energy distributions and electron thermal nonequilibrium with the heavy species for Maxwellian electron distributions. In the LSC wave power regime it was found that the electron energy distributions were essentially Maxwellian and that electron thermal nonequilibrium did not significantly affect wave propagation characteristics. Nitrogen spectroscopy was discussed, and particular features of nitrogen emission and absorption of radiation were identified as being important to radiative ionization processes and the general radiation transport problem. Chemical and ionic reactions involving atomic and molecular nitrogen and their ions were discussed, and the important reactions and their associated rates were identified. Finally, a simple, one-dimensional hydrodynamic computer code incorporating thermal radiation transport, laser absorption processes and chemical and ionic reactions was applied to two examples (at 100,000 and 1,000,000 watts/sq cm). Calculations showed that although there was substantial chemical and ionic nonequilibrium in the ionization breakdown region, these nonequilibria had a negligible effect on the propagation characteristics predicted by the equilibrium model. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1976
- Accession Number
- ADA027505
Entities
People
- James H. Havey Jr
Organizations
- Air Force Institute of Technology