Accession Number:

AD0750553

Title:

A Study of Electron Collision Frequency in Air Mixtures and Turbulent Boundary

Descriptive Note:

Technical rept. May 1970-Mar 1971

Corporate Author:

AIR FORCE WEAPONS LAB KIRTLAND AFB NM

Personal Author(s):

Report Date:

1972-10-01

Pagination or Media Count:

68.0

Abstract:

The electron collision frequency is a critical parameter in determining the attenuation of electromagnetic signals transmitted through the plasma sheath surrounding advanced reentry vehicles. This study improves current methods of obtaining this parameter for multicomponent gas mixtures. A multicomponent collision frequency model is defined with temperature and species-dependent electron collision cross sections. A parametric study of collision frequency in a gaseous mixture of phenolic carbon and air is performed using this model, and the results are compared to calculations made using a constant cross-section, clean air model. A study of collision frequency and signal attenuation in turbulent boundary layers is performed using the multicomponent and constant cross-section models. This study shows that the multicomponent model can predict collisions frequencies in an ablation air mixture that are significantly different from those predicted by constant cross- section models.

Subject Categories:

  • Plasma Physics and Magnetohydrodynamics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE