Detailed studies of soot formation in laminar diffusion flames for application to modeling studies. Annual report, 1 February 1992-31 January 1993

Technical Report · Mon Mar 01 04:00:00 EST 1993

OSTI ID:7368941

Santoro, R J

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.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical Engineering
• OSTI ID: 7368941
• Report Number(s): AD-A-264827/7/XAB; CNN: AFOSR-90-0285
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
ACETYLENE
AGGLOMERATION
ALKANES
ALKYNES
AROMATICS
BENZENE
CHEMICAL PROPERTIES
CHEMICAL REACTION KINETICS
COMBUSTION KINETICS
COMBUSTION PRODUCTS
DIFFUSION
FLAMES
FLUID FLOW
FLUORESCENCE
FRACTALS
HYDROCARBONS
KINETICS
LAMINAR FLOW
LUMINESCENCE
MASS SPECTRA
METHANE
MOLECULAR STRUCTURE
ORGANIC COMPOUNDS
PARTICLE SIZE
POLYCYCLIC AROMATIC HYDROCARBONS
REACTION KINETICS
SIZE
SOOT
SPECTRA