Numerical modeling of flow structures over various flat-topped stockpiles height: Implications on dust emissions

Fugitive dust emissions from open stock yards for bulk materials, such as coal or ores, can represent a significant part of overall estimated atmospheric emission on industrial site, as example on steel plant sites. Stockpile topography is known to modify the near field uptake force of the wind through changes of the mean flow. Various studies have shown that aeolian erosion strongly occurs on the stockpile crest, so it appears relevant to carry out a study to analyze the effect on the dust emissions of the stockpile clipping. Three-dimensional numerical simulations were done with the aim of simulating wind flow over different flat-topped pile scenarios, corresponding to a constant material volume. Various wind flow directions were tested to determine its impact on particle emissions. Data obtained from Computational Fluid Dynamics simulations were then integrated in order to estimate the effect of the clipping on the stockpiles dust emission rates by using the EPA's emission factors method. Results provide evidence to suggest that clipping stockpiles does not reduce dust emissions. This study provides to industrial operators some informations on the best geometrical pile characteristics in order to limit particles emissions.