Accession Number : AD0866611

Title :   Spectral Emission and Absorption Coefficients and Nonequilibrium Thickness of Reflected Shock Waves in Air.

Descriptive Note : Technical rept. Mar 68-Jun 69,

Corporate Author : NEW MEXICO UNIV ALBUQUERQUE ERIC H WANG CIVIL ENGINEERING RESEARCH FACILITY

Personal Author(s) : Wilson, Leroy Edward ; Skoglund, Victor J.

Report Date : FEB 1970

Pagination or Media Count : 100

Abstract : Hypersonic vehicle design involves estimates of radiation heat transfer from equilibrium and nonequilibrium regions of gases behind strong shock waves. This investigation experimentally measured spectral emission and absorption coefficients and nonequilibrium thickness of strong reflected shock waves in air. Theoretical equations for spectral intensity as a function of spectral emission, absorption coefficients, and radiation thickness were developed. The theory provides significant new information on interpretation of the data. Spectral emission and absorption coefficients of equilibrium air were determined from spectral intensities by using the theory of least squares. Nonequilibrium thickness was obtained by a special iteration technique. Acceleration of the reflected shock wave was included in the data reduction. The results are compared to the data of other investigators. The method developed for determining spectral emission and absorption coefficients is an improvement over previous methods. The overall relaxation time of reflected shock waves in air is greater than the chemical relaxation time. (Author)

Descriptors :   (*REENTRY VEHICLES, PLASMA SHEATHS), (*SHOCK WAVES, SPECTRUM SIGNATURES), EMISSIVITY, SHOCK TUBES, QUANTUM THEORY, HYDRODYNAMICS, KINETIC THEORY, TRANSPORT PROPERTIES, PLASMAS(PHYSICS), NITROGEN, AIR, OXYGEN, NITROGEN OXIDES, ABSORPTION SPECTRA, ATOMIC SPECTROSCOPY.

Subject Categories : Guided Missile Dynam, Config & Cntrl Surfaces
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE