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A new method has been developed for improving radiative transfer calculations in particle-laden flows such as pulverized coal clouds. This method takes into account the scattering characteristics of single particles derived from Lorenz-Mie theory.

The improved calculation method realized for this study is a so-called flux method, used for solving the equation of radiative transfer. This equation expresses the variation of monochromatic radiation intensity along a path through an absorbing, emitting and scattering medium. For a medium such as a particle-laden flow, the coefficients appearing in this equation can be expressed in terms of the particles scattering characteristics and are calculated through the Lorenz-Mie theory. Then the coefficients show asymptotic behaviour; scattering and absorption efficiencies are approximately equal; scattering is strongly anisotropic, forward scattering being preponderant.

When applied to a 100 kW pulverized coal combustor the improved two-flux method leads to an accurate description of radiative transfer and exhibits clearly the influence of this transfer on coal particles history.

The improved calculation method realized for this study is a so-called flux method, used for solving the equation of radiative transfer. This equation expresses the variation of monochromatic radiation intensity along a path through an absorbing, emitting and scattering medium. For a medium such as a particle-laden flow, the coefficients appearing in this equation can be expressed in terms of the particles scattering characteristics and are calculated through the Lorenz-Mie theory. Then the coefficients show asymptotic behaviour; scattering and absorption efficiencies are approximately equal; scattering is strongly anisotropic, forward scattering being preponderant.

When applied to a 100 kW pulverized coal combustor the improved two-flux method leads to an accurate description of radiative transfer and exhibits clearly the influence of this transfer on coal particles history.