Flamelet Surface Density and Burning Rate Integral in Premixed Combustion

Abstract

We have developed, tested and applied in V-flames and a spark ignition engine a new experimental method, crossed-plane laser imaging, for measuring flamelet surface normals in premixed turbulent flames. The method consists of taking simultaneous planar images in two orthogonal, laser illumination planes, and finding the flamelet normal at points along the line of intersection between the two planes where the flamelet crosses the line. In each image, the curve of intersection between the flamelet and the laser illumination plane is determined. Tangents to these curves are tangents to the flamelet surface, and where flamelet curves in the two illumination planes intersect, the normal is obtained from the cross product of the intersecting tangent lines. Flamelet data obtained with the method are used to determine probability density functions of normals, flamelet crossing densities, flamelet surface densities, and estimates of the burning rate integral. In addition, two-component laser Doppler velocimetry has been combined with compensated fine-wire thermocouple thermometry to obtain mass flux data required for calculating the burning rate integral. Measurements have been made on several methane-air V-flames. The results demonstrate the utility of the method and the potential for turbulent burning velocity data to over estimate the acceleration of combustion by turbulence. Also, the performance of ionization probes in premixed turbulent flame studies was evaluated.

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Document Details

Document Type
Technical Report
Publication Date
Mar 12, 1999
Accession Number
ADA365200

Entities

People

  • F. C. Gouldin

Organizations

  • Cornell University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Burning Rate
  • Chemical Reactions
  • Combustion
  • Computational Science
  • Fluid Mechanics
  • Geometry
  • Image Processing
  • Information Science
  • Laser Beams
  • Laser Induced Fluorescence
  • Lasers
  • Measurement
  • Mechanical Engineering
  • Probability
  • Spark Ignition
  • Statistics
  • Waveplates

Fields of Study

  • Physics

Readers

  • Approximation Theory.
  • Combustion science or combustion engineering.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers