Numerical investigation of the radiative properties of a fully resolved particle cloud

In this study, the interaction of thermal radiation with dense solid fuel particle clouds is investigated numerically. To determine absorption and scattering properties of a particle cloud, generally, the absorption and scattering efficiencies of single particles are calculated by Mie theory, and subsequently, these parameters are linearly scaled by the particle number density to obtain representative coefficients for the particle cloud. Theoretically, this approach is only valid for clouds with perfectly uniformly distributed particles. However, real particle clouds are characterized by non-uniform particle distributions within the cloud. This results in the radiation being able to penetrate areas with low particle concentration almost unhindered, while areas with high particle concentrations are subject to multiple particle-radiation interactions.