Detailed Studies of Soot Formation in Laminar Diffusion Flames for Application to Modeling Studies

Abstract

A study of soot particle formation in laminar diffusion flames has been undertaken to investigate soot precursor chemistry, particle inception and surface growth phenomena. During the first year of this study emphasis has been given to species concentrations measurements made using mass spectrometric techniques. These measurements have demonstrated that species measurements can be obtained in particle laden regions of diffusion flames using a novel sampling probe approach. In particular, measurements have been obtained of acetylene, diacetylene, benzene and stable combustion products throughout methane/air and ethene/air laminar diffusion flames. Combining these measurements with previous soot particle and velocity field measurements it has been possible to follow the soot growth process along individual particle paths. These results establish that soot particle growth ceases due to the depletion of growth species not through the loss of soot particle reactivity as observed in premixed flame studies. Similarly, laser-induced fluorescence measurements of polynuclear aromatic hydrocarbons have been undertaken to follow the evolution of the soot precursor field. These measurements have established that laser-induced fluorescence can be used to reveal the qualitative structure of the molecular growth process leading to soot particle formation. These results need to be extended to provide more quantitative comparisons, particularly regarding fuel structure effect. Additional studies have been carried out to characterize the effects of aggregates on the interpretation of light scattering measurements. The results of these studies have shown that through the incorporation of fractal analysis a self-consistent treatment of aggregates can be incorporated into the light scattering analysis

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1993
Accession Number
ADA264827

Entities

People

  • Robert J. Santoro

Organizations

  • Pennsylvania State University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Alkynes
  • Chemistry
  • Combustion
  • Computers
  • Detection
  • Distribution Functions
  • Dye Lasers
  • Engineering
  • Flow Rate
  • Laser Induced Fluorescence
  • Lasers
  • Mass Spectrometers
  • Measurement
  • Mechanical Engineering
  • Optical Properties
  • Turbines
  • Two Dimensional

Readers

  • Aerosol Science/Aerosol Physics
  • Combustion science or combustion engineering.

Technology Areas

  • Directed Energy