Research On Improving Anti-infrared Efficiency Of Red Phosphorus Smoke

The forming, diffusion and momentum transfer of the red phosphorus smokescreens and the kinetic characteristic of the different scale particles in smoke cloud are researched in this paper. Based on these, to increase the mass concentration of smoke cloud, and then, the obscuring performance in infrared band of red phosphorus smoke projectile is improved efficiently through reloading the charge structure.Explosion forming simulation model for smoke cloud is established based on rapid-expanding smoke cloud and continuous-smoking pellet's shiver of smoke projectile. The model is verified by experiment, and is used to analyze the law of smoke cloud formed by explosion.The law of smoke cloud diffused in air is studied. Based on the analytic solution of diffusion equation and the turbulent diffusion characteristic of smoke cloud, the turbulent diffusion model is established. The relation equation between smoke efficiency obscuring area, the obscuring ratio, the efficiency obscuring time, and the diffusion coefficient is derived, and the diffusion law of smoke cloud in infrared and visible light band is investigated.According to the multi-phase flow theory, the dynamic characteristic and momentum transfer process of smoke particles are analyzed. Investigation reveals that smoke particles kinestate is decided mainly by the relative velocity between smoke cloud and particles and the smoke cloud turbulent intensity. As a result, improving the technical approach for obscuring ability of red phosphorus smoke projectile in infrared band is brought forward, and the performance of the smoke projectile is designed based on the technical approach is analyzed.The relative measure method, which is used to test the smoke obscuring ratio, and the wavelets method, which is corresponded the efficient obscuring area to the obscuring ratio, are presented. Thereby, the performance of anti-infrared smoke can be evaluated systematically.