Part I. Radiative Transfer Studies and Opacity Calculations for Heated Gases. Part II. Absolute Intensity Measurements for the 2.7 µ Band of Water Vapor in a Shock Tube

Citation

Patch, Richard Walker (1964) Part I. Radiative Transfer Studies and Opacity Calculations for Heated Gases. Part II. Absolute Intensity Measurements for the 2.7 µ Band of Water Vapor in a Shock Tube. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/G92Q-ED75. https://resolver.caltech.edu/CaltechETD:etd-10292002-112946

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. PART I. Equations for radiative transfer of energy in hot gases are presented for cases involving absorption, spontaneous emission, induced emission, and isotropic scattering. Application of these equations to energy transfer between two infinite parallel plates and also to energy transfer to the nose cone of a reentry vehicle are reviewed. The Planck and Rosseland mean free paths for radiation are derived. It is shown that the treatments by Nachbar and Simon can be combined to give the continuity, momentum, and energy equations for a reacting, multicomponent gas mixture with radiative energy transfer. The resulting equations are then nondimensionalized. The coupling of radiation and convection in detached shock layers is reviewed. A simplified method for calculating spectral absorption coefficients for electronic bands of diatomic molecules is presented. A simplified method for calculating continuum radiation in plasmas is reviewed. PART II. The apparent spectral absorption coefficients of the H2O infrared bands in the vicinity of 2.7 [microns] were measured in a shock tube behind reflected shock waves in an H20-Ar mixture. By interrupting an infrared beam at a 60 kc rate and projecting this beam across the shock tube to a monochromator, it was possible to simultaneously measure both emission and absorption of H2O at 1000[degrees]K. The spectral absorption coefficients obtained from emission measurements averaged 9.8% higher than absorption coefficients obtained from absorption measurements, probably due to experimental errors (smaller than usually encountered in shock tube measurements). At 1933[degrees]K experimental difficulties precluded simultaneous measurement of infrared emission and absorption, so measurements were restricted to emission. The apparent absorption coefficients were integrated to give the integrated absorption coefficients for the collections of bands near 2.7[microns]. Integrated absorption coefficients were 49.8 cm[superscript -2] atm[superscript -1], 54.7 cm[superscript -2] atm[superscript -1], and 31.6 cm[superscript -2] atm[superscript -1] for absorption at 1000[degrees]K, emission at 1000[degrees]K, and emission at 1933[degrees]K, respectively. The two values at 1000[degrees]K were in good agreement with those of Goldstein, who made no measurements above this temperature. Photographic materials on pp. 100, 107, 111, 123, and 128 are essential and will not reproduce clearly on Xerox copies. Photographic copies should be ordered.

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