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Author
Vandsburger, U. | Kennedy, I. M. | Glassman, I.
Title
Sooting Counter-Flow Diffusion Flames With Varying Velocity Gradients.
Coporate
Princeton Univ., NJ
Sponsor
National Bureau of Standards, Gaithersburg, MD
Book or Conf
Combustion Institute, Symposium (International) on Combustion, 20th. August 12-17, 1984, Combustion Institute, Philadelphia, PA, Michian Univ., Ann Arbor, 1105-1112 p., 1984
Keywords
soot
Abstract
The influence of varying the oxidizer stream velocity on the sooting structure of an ethylene/air counter-flow diffusion flame, stabilized around a porous cylinder, has been examined. Laser light scattering and extinction measurements have been made to determine the soot parameters in the forward stagnation region. Temperature and velocity were measured to locate the flame front and to enable calculation of the soot residence time and growth rates. The variation of the peak measured temperature was very small (1907-1927 deg. K). The number of soot particles did not vary significantly within this velocity range. Maximum particle size decreased with increasing oxidizer velocity as a result of the reduced residence time for coagulation and for surface growth reactions with fuel pyrolysis products. For velocities of 21, 38, and 58 cm/sec the rates are very similar close to the flame front, but deviate later on. In the highest approach velocity case, 67 cm/sec, the growth rate is lower than those of the other cases also in the immediate vicinity of the flame front (where the soot particles are young and thus have a high surface reactivity).