Initiation and Modification of Reaction by Energy Addition: Kinetic and Transport Phenomena
Abstract
Laboratory experiments, supplemented by approximate theoretical studies, have been carried out on the photochemical ignition of a flowing homogeneous gaseous fuel-oxidizer premixture by nonintrusive energy addition. In the experimental task, we have successfully demonstrated the ignition of H2/O2 and CH4/O2 mixtures with photolysis of NH3 by use of an ArF laser at 193 nm. The theory, by a combination of numerical and approximate analytic methods, examines the interaction of premixture stoichiometry, preferential diffusion (i.e., differing diffusivities for heat and species), and flame radius, with respect to the outward propagation of a laminar flame from a single spheroidal kernel (if a flame develops). Previously reported observations of the variation of the flame- front speed with flame radius, sometimes interpreted in terms of preferential- diffusion effects but probably better interpreted in terms of radiative heat loss, have been examined; the need exists for further spherical-flame- propagation experiments, with emphasis on measurements taken when the flame radius is more nearly comparable to the flame thickness. (ttl)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1990
- Accession Number
- ADA229591
Entities
People
- F. E. Fendell
- G. F. Carrier
- M. S. Chou
- T. J. Zukowski