Detailed Structure Study of an H2/N2O/Ar Flame Employing Molecular Beam Mass Spectrometry, Laser Spectroscopy, and Modeling

Abstract

A combined experimental and detailed chemical modeling study has been performed on a 20-torr, stoichiometric H2/N2/O/Ar burner stabilized flame. This study provides a check of part of the mechanism to be used in models for the combustion of solid nitramine propellants. Species concentration profiles were measured using molecular beam sampling with mass spectrometric detection and laser-induced fluorescence, while temperature profiles were measured with coated Pt/Pt-Rh(10%) thermocouples. The burned gases of the flame contain about 2 mole % of NO and H2, a concentration of approximately 10 times more than that of their equilibrium. This formation prevents full energy release of the systems within or near the flame zone. Experimental flame profiles of the major species, H2, N2O, N2, and H2O, as well as the minor species, NO, O2, OH, H, O, and NH, are presented and compared to calculated profiles generated by PREMIX, a one- dimensional premixed laminar flame code. The chemical mechanism used in the flame code was derived from a critical literature review and consists of 38 reactions and 14 species. Rate and sensitivity analyses performed reveal the intricacies of the mechanism as well as reactions important in the modeling of the experimental results. Several key reactions, including N2)+OH=HO2+N2=NO+NH, whose rate coefficients have been controversial, are discussed in detail. In addition, the importance of various collision partners in the key initiation step, N2O + M=N2+O+M, is presented and discussed.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1993
Accession Number
ADA270720

Entities

People

  • Cynthia M. Faust
  • David C. Dayton
  • Rosario C. Sausa
  • Stephen L. Howard
  • William R. Anderson

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Burning Rate
  • Chemical Reactions
  • Chemistry
  • Combustion
  • Energy Transfer
  • Engineering
  • Engineers
  • High Temperature
  • Jet Propulsion
  • Laser Induced Fluorescence
  • Laser Spectroscopy
  • Lasers
  • Low Temperature
  • Mechanical Engineering
  • Military Research
  • Physical Chemistry
  • Thermodynamic Properties

Fields of Study

  • Physics

Readers

  • Combustion science or combustion engineering.

Technology Areas

  • Directed Energy