ENVIRONMENTAL IMPACT OF DIFFUSION CHARACTERISTICS OF SMOKE PARTICLES

摘要

According to the particle collision dynamics theory, the smoke particles motion-collision decoupled models were built to describe the formation procession of smokescreen. The dispersion characteristics of smoke particles in the process of smokescreen by pneumatic spray were studied. The smoke collision diffusion dynamical model was built and the smoke collision spray process was numerical simulated using the DSMC method with the gas phase flow field-smoke particle velocity field and concentration distribution carefully examined. The results showed that the calculation results corresponded with experiment and the DSMC method can effectively simulate the smoke collision spray process. After the jet current has met, the smoke turned upward movement and the smoke velocity decreased. In the expansion current action, the smoke diffused outside with the shape of cone. The smoke density max value is in the jet current area and collision area. As for the collision effect was weak, the smoke diffusion movement enhanced and the smoke density reduced with the height increment.