Accession Number : ADA264827


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


Descriptive Note : Annual rept. 1 Feb 92-31 Jan 93,


Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING


Personal Author(s) : Santoro, Robert J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264827.pdf


Report Date : 01 Mar 1993


Pagination or Media Count : 52


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


Descriptors :   *PARTICLES , *DIFFUSION , VELOCITY , FRACTALS , DEPLETION , LIGHT SCATTERING , MEASUREMENT , PROBES , SOOT , BENZENE , MODELS , LASER INDUCED FLUORESCENCE , AIR , PRECURSORS , COMPARISON , STRUCTURES , REACTIVITIES , SURFACES , CHEMISTRY , ACETYLENES , COMBUSTION PRODUCTS , MASS SPECTROMETRY , LAMINAR FLOW , METHANE , FLAMES , MOLECULAR STRUCTURE , AROMATIC HYDROCARBONS , SAMPLING , FUELS


Subject Categories : Organic Chemistry
      Fluid Mechanics
      Optics
      Combustion and Ignition


Distribution Statement : APPROVED FOR PUBLIC RELEASE