Mixing and Radiation Properties of Buoyant Luminous Flame Environments.
Mixing and Radiation Properties of Buoyant Luminous
Flame Environments.
(4134 K)
Dai, Z.; Krishnan, S. K.; Sangras, R.; Wu, J. S.; Faeth,
G. M.
NIST GCR 96-691; GDL/GMF-95-02; 90 p. June 1996.
Sponsor:
National Institute of Standards and Technology,
Gaithersburg, MD
Available from:
National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
Telephone:
1-800-553-6847 or 703-605-6000;
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Order number: PB96-202254
Keywords:
diffusion flames; fire research; optical properties;
soot; turbulent flames
Abstract:
An investigation of the radiation and mixing properties
of buoyant turbulent diffusion flames is described. The
study was divided into two phases: (1) the optical and
radiative properties of soot, which must be understood
in order to develop non-intrusive methods for measuring
soot properties and to estimate the continuum radiation
properties of soot in flame environments, and (2) the
structure and mixing properties of buoyant turbulent
plumes, which must be understood in order to resolve
effects of turbulence/radiation interactions and to
benchmark computationally tractable models of buoyant
turbulent flows. Consideration of the optical and
radiative properties of soot involved evaluation of the
Rayleigh-Debye-Gans (RDG) scattering approximation for
soot aggregates and the use of this theory to measure
the refractive indexes in the visible region (350-800
nm). In addition, dimensionless extinction coefficients
and the soot fractal dimensions were measured. The
structure and mixing properties of buoyant turbulent
plumes were investigated by examination of the effects
of coflow on earlier measurements and by evaluating
various modeling approximations, with an emphasis on
self-preserving round buoyant turbulent plumes.
