火灾烟颗粒的分形结构形状模拟与光散射计算

针对火灾烟颗粒的形状特点，提出并建立火灾烟颗粒分形结构凝团的形状模型，并对烟颗粒扫描电镜(SEM)图像进行分析，获取分形结构模型中的单个凝团中基本颗粒个数、凝团分形维数、基本颗粒半径等参数.利用该模型对火灾烟颗粒的形状进行模拟的结果表明，该模型能够较好反映出烟颗粒的形貌特征.利用形状模型对火灾烟颗粒散射进行初步计算表明，在其他参数相同的情况下，相对于同体积的球形颗粒，分形凝团具有前向散射较弱，后向散射较强的特征.

Fractal shape simulation and light scattering calculation of fire smoke particles

A fractal shape model was used to simulate the morphology of fire smoke particles, as the aggregated spherical particles have intrinsical fractal structures. The shape model, whose parameters, including the total number of primary spherical particles in an aggregate, the fractal dimension and the radius of the primary particles, were obtained from a sequence of SEM images, was considered to be compatible with the smoke particle shape. The shape model was then used to compute the light scattering of smoke particles, and the results showed that, compared with the spherical particle with the same volume and other optical parameters, the fractal-like aggregate has smaller forward scattering and larger backward scattering.