Accession Number:

ADA370998

Title:

Line-by-Line Infrared Spectra Calculations of Combustion Products Including Doppler Shifts and Vibrational Nonequilibrium

Descriptive Note:

Corporate Author:

ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFS TN

Report Date:

1999-01-14

Pagination or Media Count:

7.0

Abstract:

A previously developed line-by-line spectral model has been extended to use the HITRAN and HITEMP line strength data bases. The new spectral model computes the line-by-line spectral radiance and transmittance of homogeneous or inhomogeneous gas paths, including the effects of Doppler shifts due to directed gas velocity and vibrational nonequilibrium. The nonequilibrium vibrational state populations can either be specified directly perhaps by a state-specific chemistry model, or by imposing rotational and vibrational temperatures for each molecular constituent. Calculations are compared to benchmark laboratory data for hot and hot-through-cold gas paths of CO2 at high and low spectral resolution. The model showed good agreement with the data, particularly near the line centers. Some discrepancies are noted in the line wings, perhaps indicating a more detailed model of the line wings is needed. Sample calculations demonstrating the effects of directed Doppler shifts and vibrational excitation behind a normal shock are presented.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE