Disection of Ignition Delay Times via Laser-Schlieren Measurements of Density Gradients at Shock Fronts.

Abstract

An experimental and analytical investigation of the initiation regimes in the pyrolysis and oxidation of methane behind shock waves has been carried out. The Laser-Schlieren technique was used to measure density gradient profiles behind incident shock waves in various CH4/Ar and CH4/O2/Ar mixtures in the temperature range 2000K to 2600K. Since the density gradient is proportional to the net rate of post-shock energy exchange, these experiments provide a highly resolved record of the net endo/exothermic balance throughout the initiation regime. In the analytical study, it was possible to ascertain which of the limited number of reactions and rates were consistent with the observed density profiles. While the induction times agreed with previous correlations, currently proposed oxidation mechanisms do not fully reproduce the observed shapes of the density gradients.

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1974
Accession Number
ADA001928

Entities

People

  • Jennifer A. Miller
  • S. H. Bauer
  • W. J. Mclean

Organizations

  • Sibley School of Mechanical and Aerospace Engineering

Tags

DTIC Thesaurus Topics

  • Chemical Reactions
  • Combustion
  • Energy
  • Energy Transfer
  • Ignition
  • Ignition Lag
  • Measurement
  • Oxidation
  • Pyrolysis
  • Shock
  • Shock Waves
  • Temperature Gradients
  • Waves

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Combustion Dynamics and Shock Wave Physics.
  • Polymer Science and Technology

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers