真空和微重力下烟幕粒子动力学特性研究

Study on Dynamics Property of Smoke Particles in Vacuum and Microgravity

为了研究红外烟幕在外层空间的适用性,基于外层空间环境高真空和微重力的特殊性,分析烟幕粒子的真空和微重力效应,采用分子运动论理论近似模拟真空和微重力下烟幕粒子的动力学特性,建立烟幕粒子间距函数模型,利用Mathematica方法计算了烟幕材料粒径、密度及粒子运动时间对粒子间距大小的影响．结果表明,随着烟幕材料粒径及密度的增大,粒子间距逐渐减小,形成烟幕的稳定性逐渐增大;粒子运动时间愈长烟幕愈不稳定．

The dynamics of smoke particles can be effectively described by the Stokes sedimentation theory and diffusion coefficient expression in normal conditions; but in vacuum and microgravity, the forementioned principles are not applied any longer. In order to study the applicability of the IR smoke in outer space, by analyzing the vacuum and microgravity effects of the smoke particles, we can simulate approximately the dynamics property of smoke particles using molecule dynamics theory. On the basis of correlative theory, the force between particles is related to the space between them. When the space is less than ten times balance space, the force is large enough to form steady smoke, otherwise, the force is too small, smoke particles cannot form steady smoke. According to the Maxwellian distribution function, a function model of space between particles is established. Based on the model, the effects of smoke materials radius r, consistency ρ and the moving time of particles t on the space between smoke particles are discussed by Mathematica method. The results show that the space reduces with the increasing of the r and ρ, the smoke screen stability will increase gradually; the more long t is, the more the space is large, the smoke screen stability will decrease.