%0 Journal Article %A Vanderhoff, J. A. %A Kotlar, Anthony J. %A Modiano, S. H. %A Teague, M. W. %D 1997 %I Begell House %N 1-6 %P 807-824 %R 10.1615/IntJEnergeticMaterialsChemProp.v4.i1-6.760 %T PROPELLANT COMBUSTION DIAGNOSTICS VIA MULTICHANNEL ABSORPTION SPECTROSCOPY %U https://www.dl.begellhouse.com/journals/17bbb47e377ce023,43cb1df7484a24f3,75e8f75c6dc9ac47.html %V 4 %X Multichannel absorption spectroscopy has been developed and used to non-intrusively probe the hostile environment of solid propellant combustion. A windowed pressure vessel, broadband light source, and a spectrometer-array detector system are the major components of the experiment. Gas phase absorption spectra obtained during the steady-state combustion of double-base and nitramine propellants can be analyzed to determine temperature and absolute concentration profiles. The analysis requires only fundamental spectroscopic data incorporated into the differential absorption law.
Ultraviolet-visible sensitive multichannel detectors have been used to obtain absorption spectra of NO, OH, NH, and CN during the combustion of solid propellants and their ingredients. Focus has been primarily on the propellant dark zone with simultaneous tracking capability for NO and OH. Vibrationally resolved transitions in the Α2Σ-Χ2Π electronic system of NO allow determination of temperature and absolute NO concentration. Rotationally resolved transitions in the Α2Σ-Χ2Π(0,0) vibrational band system of OH allow determination of OH concentration and luminous flame temperature. An infrared-sensitive multichannel detector has been used to obtain rotational-vibrational absorption spectra for CO, HCN, H2O, CO2, N2O, and CH4 in the dark-zone region. Substantial HCN concentrations occur in the dark zone of nitramine propellants, but not in the dark zone of double base propellants. Dark-zone temperatures derived from fitting the infrared absorption spectra of HCN and H2O are in good agreement with those obtained from fitting NO in the ultraviolet region. Concentrations of these infrared active species have been determined.
Multichannel absorption spectroscopy, along with other experimental diagnostic techniques such as microprobe mass spectrometry, FT-IR spectroscopy and use of thermocouples, have greatly expanded the propellant database for quantitative gas-phase composition and temperature profiles. This information is presently being used to refine reduced reaction mechanisms for propellant dark-zone chemistry as well as to validate models of solid propellant combustion. %8 1997-01-01