Radiative transfer through an inhomogeneous fly-ash cloud; Effects of temperature and wavelength dependent optical properties
Journal Article
·
· Numerical Heat Transfer. Part A, Applications; (United States)
- Dept. of Mechanical Engineering, Univ. of Kentucky, Lexington, KY (US)
In this paper the effect of spectral radiative properties of fly-ash particles on radiative heat transfer through an inhomogeneous planar layer near the walls of a combustion system is investigated. The spectral absorption and scattering coefficients, as well as the scattering phase function of the particles, are obtained from the Lorenz-Mie theory as functions of temperature and particle diameter. These data are employed in the solution of the radiative transfer equation, which is modeled using a double spherical harmonics approximation. In the calculations, a linearly anisotropic scattering phase function is used. It is shown that, if the medium temperature distribution is nonuniform, the divergence of the radiative flux term calculated using the spectral fly-ash properties differs significantly from that obtained using constant properties. This means that if fly-ash properties are assumed wavelength independent, a coupled radiation-convection heat transfer analysis would underestimate the gas temperature near the walls of a typical furnace. On the other hand, the temperature dependency of the fly-ash radiative properties is quite weak and can safely be neglected.
- OSTI ID:
- 5271650
- Journal Information:
- Numerical Heat Transfer. Part A, Applications; (United States), Journal Name: Numerical Heat Transfer. Part A, Applications; (United States) Vol. 21:3; ISSN 1040-7782; ISSN NHAAE
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
421000 -- Engineering-- Combustion Systems
ABSORPTION SPECTRA
AEROSOL WASTES
ASHES
CALCULATION METHODS
COMBUSTION PRODUCTS
COMBUSTORS
COOLING
ENERGY TRANSFER
FLY ASH
HEAT TRANSFER
OPTICAL PROPERTIES
PARTICLE SIZE
PHYSICAL PROPERTIES
RADIATIVE COOLING
RESIDUES
SIZE
SPECTRA
TEMPERATURE DEPENDENCE
TEMPERATURE EFFECTS
WALLS
WASTES
WAVELENGTHS
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
421000 -- Engineering-- Combustion Systems
ABSORPTION SPECTRA
AEROSOL WASTES
ASHES
CALCULATION METHODS
COMBUSTION PRODUCTS
COMBUSTORS
COOLING
ENERGY TRANSFER
FLY ASH
HEAT TRANSFER
OPTICAL PROPERTIES
PARTICLE SIZE
PHYSICAL PROPERTIES
RADIATIVE COOLING
RESIDUES
SIZE
SPECTRA
TEMPERATURE DEPENDENCE
TEMPERATURE EFFECTS
WALLS
WASTES
WAVELENGTHS