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Non-Boltzmann Modeling for Air Shock-Layer Radiation at Lunar-Return ConditionsThis paper investigates the non-Boltzmann modeling of the radiating atomic and molecular electronic states present in lunar-return shock-layers. The Master Equation is derived for a general atom or molecule while accounting for a variety of excitation and de-excitation mechanisms. A new set of electronic-impact excitation rates is compiled for N, O, and N2+, which are the main radiating species for most lunar-return shock-layers. Based on these new rates, a novel approach of curve-fitting the non-Boltzmann populations of the radiating atomic and molecular states is developed. This new approach provides a simple and accurate method for calculating the atomic and molecular non-Boltzmann populations while avoiding the matrix inversion procedure required for the detailed solution of the Master Equation. The radiative flux values predicted by the present detailed non-Boltzmann model and the approximate curve-fitting approach are shown to agree within 5% for the Fire 1634 s case.
Document ID
20080043603
Acquisition Source
Langley Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Johnston, Christopher O. (NASA Langley Research Center Hampton, VA, United States)
Hollis, Brian R. (NASA Langley Research Center Hampton, VA, United States)
Sutton, Kenneth (National Inst. of Aerospace Associates Hampton, VA, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2008
Subject Category
Lunar And Planetary Science And Exploration
Distribution Limits
Public
Copyright
Public Use Permitted.

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