Nonuniform absorption of thermal radiation in semitransparent spherical particles under conditions of arbitrary illumination of a disperse system

Abstract

Different methods of calculating the nonuniform absorption of radiation in spherical particles are treated. An approximate representation of asymmetric illumination of a particle is used in application to heat transfer problems characterized by diffuse radiation in a wide spectral range. In each spectral range, the illumination of the particle is assumed to be uniform but varying in intensity from the front and rear hemispheres (with respect to the spectral radiation flux). The Mie theory is used to solve the problem, and the modified differential approximation is used in the case of symmetric illumination of large particles. Approximate analytical relations are obtained for the distribution of the power of absorbed radiation in the volume of a large semitransparent particle. Calculation data are given for droplets of water and diesel fuel.

Heterogeneous thermochemical decomposition of a semi-transparent particle under high-flux irradiation: uniform versus non-uniform irradiation

“…Non-uniform irradiation of optically large particles results in non-uniform temperature and chemical reaction rate that may significantly affect the overall decomposition time. Examples of previous pertinent studies of radiative heat transfer in optically large semi-transparent particles exposed to nonuniform external irradiation can be found in [11,12]. In this work, we extend the conjugate heat transfer analyses of uniformly-irradiated large and semi-transparent CaCO 3 particles undergoing thermal decomposition presented in [13,14] to investigate the effects of non-uniform particle irradiation.…”