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烟幕透过率是表征烟幕干扰性能的重要参数。以等效粒径为0.1μm的石墨为例,就不同形状的石墨粒子组成的烟幕,基于蒙特卡罗方法对烟幕透过率进行了数值计算。利用Mie散射理论和离散偶极子近似(DDA)方法分别计算了球形粒子、椭球形粒子和圆柱形粒子对1.06μm波长的入射光单次散射的消光参量。对于入射光在烟幕中的传输,建立了蒙特卡罗模拟计算模型,利用MATLAB语言编制了相应的计算程序,给出了不同纵横比的椭球形粒子和圆柱形粒子相应的烟幕透过率计算结果,并和等体积球粒子相应的烟幕透过率进行了比较分析。结果表明:透过率与烟幕中粒子形状、粒子数密度、入射光的入射角度及烟幕厚度有关,粒子形状越偏离球形,对应透过率越小。
Smoke screen transmittance is an important parameter to characterize the performance of smoke screen. Taking the graphite with the equivalent particle size of 0.1μm as an example, the smoke screen composed of different shapes of graphite particles was calculated based on the Monte Carlo method. Using the Mie scattering theory and the discrete dipole approximation (DDA) method, the extinction parameters of spherical, ellipsoidal and cylindrical particles for the single scattering of incident light at 1.06 μm were calculated. For the transmission of incident light in the smoke screen, a Monte Carlo simulation calculation model is established, and the corresponding calculation program is compiled by MATLAB language. The calculation results of the corresponding smoke screen transmittance of ellipsoidal particles and cylindrical particles with different aspect ratios are given , And compared with the equivalent volume of particles of the smoke screen through a comparative analysis. The results show that the transmittance is related to the shape of particles, the number density of particles, the angle of incidence of incident light and the thickness of the smoke screen. The more the shape of the particles deviates from the sphere, the smaller the corresponding transmittance is.