Investigation of Radiative Properties of a Multi-particle Cloud with Non-uniform Particle Size Distribution

Abstract

Particle systems involve numerous fields such as combustion, oceanography, photocatalysis, and atmospheric science, among others. In fact, most of these systems were in the form of multi-particle systems composed of different types of particles. In most previous studies, the influence of the type of element on radiative characteristic parameters was not considered, or the effective medium theory was adopted, which led to large calculation errors. In this paper, the differential-integration algorithm developed based on the Mie theory was used to calculate the radiative characteristics (extinction coefficient, absorption coefficient, scattering phase function, asymmetry factor) of a multi-particle system with non-uniform size distribution, and the Monte Carlo ray-tracing (MCRT) method was used to solve the radiative transfer equation (RTE). SiO2 particles and polystyrene particles were investigated and subsequently divided into two categories: submicron particles (χ >1) and nano particles (χ >1) according to the size parameter. The radiative characteristics and spectral transmittance of particles with different volume fraction ratios and different particle sizes in the multi-particle system were also investigated. The results of the proposed method were compared to those of experimental tests to verify the accuracy of the algorithm. The maximum relative transmittance error decreased from 30.1% to 0.77%, and the average error decreased from 18.78% to 0.67%.