随机取向烟尘团簇粒子激光散射特性研究

Research on Laser Scattering Property by Randomly Oriented Soot Clustered Agglomerates

利用蒙特卡罗方法根据团簇-团簇凝聚(CCA)模型对由球形原始粒子凝聚而成的烟尘团簇粒子进行了模拟,用离散偶极子近似(DDA)方法研究了烟尘团簇粒子随机取向时的激光散射特性,并与等效球形粒子的激光散射特性进行了比较。结果表明,等效球形粒子的激光散射特性与随机取向烟尘团簇粒子的激光散射特性存在着明显差别,不能用等效球形粒子来代替随机取向的团簇粒子;随机取向的烟尘团簇粒子的激光散射特性受基本粒子数量和粒径的影响比较大。该结果将为进一步研究随机取向团簇粒子的形成机理、形态特性以及激光在其中的传输特性提供了一种理论方法。

Cluster-cluster aggregation（CCA） model based on Monte-Carlo method is used to simulate the structure of the fractal-like soot clustered agglomerates consisting of spherical primary particles,and numerical calculations are carried out on laser scattering by randomly oriented soot clustered agglomerates based on the discrete dipole approximation（DDA） method.Comparison of the laser scattering properties between equivalent spherical particles and randomly oriented soot clustered agglomerates shows that the differences between them are obvious.The scattering properties on randomly oriented soot clustered agglomerates are determined by the radius and number of primitive particles besides the refractive index.This research will provide an effective theoretical approach for the research of formation mechanism,structural characteristics of randomly oriented soot clustered agglomerates and propagation property of laser in them.