Abstract:To investigate the particles diffusion caused by natural wind in open-air coal yard, the stochastic trajectory modeling was employed based on the dynamical computational method. The ground concentrations were calculated for the four kinds of coal powder named as crude coal, blocked coal, watered coal and refined coal. Afterwards, wind-tunnel experiment was conducted and comparison was made between the measured values and predicted ones. The results illustrated that the calculated error was limited within ±25%, especially, for crude coal powder the error range was 10%. Comparison with the dynamical mode, the Gauss mode predicted much larger values than the actual conditions for ground concentration where coal particle sources. By contrast, the dynamical mode focused on the particle travelling behaviors during the diffusion in the air, consequently, could accurately describe the coarse particle statement. For particles within Rosin-Rammler size distribution, the dynamical mode had good prediction.