Understanding the radiative properties of particles is essential for interpreting and analyzing atmospheric remote sensing, target detection, combustion diagnostics, etc. At present, there is a relative lack of studies and understanding of the radiative properties of large aggregate particles. In this work, we comprehensively investigate the radiative properties of large dust aggregate particles via the developed Monte Carlo ray tracing method. Large dust aggregate models with monodisperse and polydisperse monomers are constructed, respectively. The effects of various factors on the radiative properties of large dust aggregate particles are analyzed. We find that the larger geometric standard deviation and the greater number of monomers lead to slightly larger backscattering and an increase of the overall radiative energy distribution on the receiving surface. With increasing the size parameter, the scattering phase function becomes smoother and the difference between the scattering phase function of spheres and aggregates diminishes. The absorptivity is proportional to the size parameter and inversely proportional to the number of monomers. At a size parameter of 100, the absorptivity and the peak of the radiative energy distribution of monodisperse monomer aggregates are higher than those of polydisperse monomer aggregates, and gradually converge with the increase of particle size parameter. Overall, this work helps to enhance the knowledge of the radiative properties of large aggregate particles.

中文翻译：

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通过 Monte Carlo 光线追踪方法研究大型尘埃聚集体颗粒的辐射特性


了解粒子的辐射特性对于解释和分析大气遥感、目标检测、燃烧诊断等至关重要。目前，对大聚集体粒子的辐射特性的研究和理解相对缺乏。在这项工作中，我们通过开发的蒙特卡洛射线追踪方法全面研究了大尘埃骨料颗粒的辐射特性。分别构建了具有单分散和多分散单体的大型尘埃聚集体模型。分析了各种因素对大尘埃骨料颗粒辐射特性的影响。我们发现，较大的几何标准差和更多的单体会导致略大的反向散射和接收面上整体辐射能量分布的增加。随着尺寸参数的增加，散射相位函数变得更平滑，球体和聚集体的散射相位函数之间的差异减小。吸收率与尺寸参数成正比，与单体数量成反比。当粒径参数为 100 时，单分散单体聚集体的吸收率和辐射能量分布峰值高于多分散单体聚集体，并随着粒径参数的增加而逐渐收敛。总的来说，这项工作有助于增强对大聚集体粒子辐射特性的了解。