采用蒙特卡罗方法，根据团簇-团簇凝聚(CCA)模型对随机取向且具有分形结构的煤烟气溶胶粒子进行了仿真模拟，利用离散偶极子近似(DDA)方法计算了随机取向的煤烟气溶胶粒子从紫外到红外波段的吸收、散射与消光效率因子，得到了太阳辐射波长、原始微粒的粒径和数目对煤烟气溶胶粒子的消光特性影响规律。通过将所得数值结果与T矩阵方法的数值结果进行比较发现，两种数值方法计算的结果非常相近，这验证了所用DDA方法的正确性。研究表明，炭和灰凝聚粒子对太阳辐射存在着不同程度的消光作用，其消光影响主要集中在紫外到近红外波段；随机取向的煤烟气溶胶粒子对太阳辐射的消光特性受基本粒子数量和粒径的影响比较大。

Based on fractal theory, the cluster-cluster aggregation (CCA) model is used to simulate the fractal structure of the soot aerosols in random orientation using Monte-Carlo method, and the absorption, scattering and extinction efficiency factors of fractal soot aerosols in random orientation are simulated in the solar radiation spectrum ranging from 0.2 to 10.0 μm of wavelength by the discrete dipole approximation (DDA) method. The influential rules about the solar radiative wavelength, diameter and the number of primary particles on the extinction characteristics of soot aerosols in random orientation are provided. The comparison of the numerical results obtained by the DDA method with T matrix method shows that the results by two methods are very similar which verifies the validity of DDA method. It is shown that the carbon and fly ash aerosols have different influences of extinction characteristics on solar radiation, whose radiative wavelength ranges from ultraviolet to near infrared bands, and the extinction characteristics of solar radiation by soot aerosols are mainly determined by the radius and the number of primitive particles besides the refractive index.