Absolute Concentration Measurements of Free Radicals in Flames by Absorption Spectroscopy

Abstract

Absorption spectroscopy techniques were used for measurement of absolute concentrations of free radical species in premixed, laminar, flat- flames of methane / nitrous oxide and CH4/nitric oxide/oxygen. Absolute concentration measurements were performed for the species hydroxyl radical, cyanide radical, and imino radical in 63 Torr flames. These absolute concentration measurements were used to calibrate relative concentration profiles taken in previous experiments using laser-induced fluorescence (LIF) spectroscopy. Significant absorptions of these species could be obtained even in the very short path length flames studied. These measurements permit the experimental LIF measurement to be directly compared to the species concentration profiles predicted by the CHEMKIN/PREMIX flames modeling code.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1991
Accession Number
ADA236032

Entities

People

  • D. A. Alspach
  • Steven Zabarnick

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Absorption
  • Amplifiers
  • Chemical Kinetics
  • Chemistry
  • Combustion
  • Emission Spectra
  • Fluorescence
  • Free Radicals
  • Laser Induced Fluorescence
  • Lasers
  • Light Sources
  • Measurement
  • Operating Systems
  • Quantum Numbers
  • Spectra
  • Spectral Lines
  • Spectroscopy

Readers

  • Combustion science or combustion engineering.
  • Spectroscopy.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers