Accession Number : ADA299516

Title :   Transport Phenomena and Interfacial Kinetics in Multiphase Combustion Systems.

Descriptive Note : Annual technical rept. 15 Feb 94-14 Feb 95,

Corporate Author : YALE UNIV NEW HAVEN CT DEPT OF CHEMICAL ENGINEERING

Personal Author(s) : Rosner, Daniel E.

PDF Url : ADA299516

Report Date : MAR 1995

Pagination or Media Count : 48

Abstract : Rational pseudo-continuum methods were developed to predict the sintering kinetics, and the associated evolution of transport properties (eg., Brownian coagulation rate constant) for aggregated soot' particles (eg., Al(2)O3, TiO(2)) containing N (>>1) primary particles in high temperature combustion gases. Results show a much weaker N-dependence of the total time required for "collapse" than N(1/3) (resulting from theories based on collapse at constant fractal dimension). Using both laser light scattering and thermophoretic sampling/TEM image analysis, comprehensive experiments were initiated to understand how changes in seed level, flame stoichiometry and strain rate influence the nature of the particles formed in the HTCRE Lab counterflow laminar diffusion flame burner. In ancillary theoretical studies, rational yet remarkably convenient methods were developed to predict the erosion rates of metal and ceramic solid surfaces (eg., circular cylinders, leading "edges") in abrasive, high-speed streams. It was found that metal targets "sharpen" while ceramic targets become "blunter" Yale HTCRE Lab experimental data motivated the development of quantitative methods for predicting/correlating the effects particle formation in CVD thermal boundary layers on the rate and surface roughness of vapor-deposited ceramic thin films. jg p.3

Descriptors :   *INTERFACES, *PHASE, *CERAMIC MATERIALS, *COMBUSTION, *TRANSPORT PROPERTIES, *KINETICS, FRACTALS, IMAGE PROCESSING, METALS, LIGHT SCATTERING, EXPERIMENTAL DATA, SIZES(DIMENSIONS), HIGH TEMPERATURE, THIN FILMS, SURFACE ROUGHNESS, RATES, CHEMICAL VAPOR DEPOSITION, TARGETS, LASERS, GASES, STRAIN RATE, EROSION, PARTICLES, CYLINDRICAL BODIES, SAMPLING, EVOLUTION(GENERAL), LEADING EDGES, FLAMES, THERMAL BOUNDARY LAYER, STOICHIOMETRY, CIRCULAR, SOLID BODIES, STREAMS, BROWNIAN MOTION, SINTERING, COAGULATION, LAMINAR BOUNDARY LAYER, COMBUSTION PRODUCTS.

Subject Categories : Combustion and Ignition
      Physical Chemistry
      Ceramics, Refractories and Glass
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE