分形烟尘簇团粒子的消光特性研究

Research on the extinction properties for fractal soot aggregation particles

根据物质的电结构,将烟尘簇团粒子离散为一系列的偶极子,利用离散偶极子近似方法,获得了不同波长电磁波入射情况下分形烟尘簇团粒子不对称因子、吸收和散射效率因子的值.结合偶极子在电磁场中的力学性质,分析了烟尘簇团粒子在外加电磁场中所受的力和力矩,给出三种分形结构烟尘簇团粒子的电磁辐射压力及电磁辐射力矩效率因子随入射波波长变化的数值结果,分析了烟尘粒子对电磁能量吸收的宏观表现和微观机理.结果显示:入射波长、烟尘簇团粒子的分形维数及所含原始微粒数目都将影响烟尘粒子的消光特性.

According to electrical structure of substance, the soot aggregation particles are dispersed into a series of dipoles, and the asymmetry parameter,the absorption and scattering efficiency factor of soot aggregation particles under different incident wavelengths are obtained by using discrete dipole approxi- mation method. Combined with the mechanical properties of dipoles in electromagnetic field, the force and torque of soot aggregation particles in external electromagnetic field are analyzed in the paper. At the same time, the numerical results of electromagnetic radiative pressure and torque efficiency factor for three kinds of fractal structure soot aggregation particles under different incident wavelengths are given, and the macroscopic representation and microcosmic mechanics of soot aggregation particles assimilating electromagnetic energy are analyzed. The results show that all of the incident wavelength, the fractal di- mension and the original particle number of soot aggregation particles can influence the extinction prop- erties of soot particles.