Atmospheric Environment: X (Jan 2024)
3D numerical simulation of airflow structure and dust emissions from an open storage pile behind a dynamic solid fence-deflector
Abstract
Open storage yards at industrial sites represent a significant fugitive dust emission source. Granular material subjected to wind erosion may emit significant dust into the atmosphere. Several windbreaks and fences with different shapes have been proposed to control and reduce those emissions. Solid fences are commonly erected around the open yard (i.e., open bays) to prevent and reduce those emissions, even though they have some limitations. The present study aims to enhance the effectiveness of solid fences by coupling them with dynamic wind deflectors. Computational fluid dynamics was employed to simulate the flow and shear stresses on storage pile surfaces using the numerical Reynolds-averaged Navier–Stokes equations and the k-ω SST turbulence model. At the same time, dust emission was estimated using an Environmental Protection Agency (EPA) method, which estimates the emission potential of a material based on the wind friction velocity and the material's threshold friction velocity. The numerical model was validated against experimental data from an EPA study. In addition, this study investigated the efficiency of various dynamic wind deflectors with different heights and inclination angles. The results showed that most of the investigated dynamic fence-deflector models reduced the velocity magnitude, vortices, and turbulence intensity, lessening the impact of shear stresses compared to single solid fences and consequently reducing the emission of dust from the exposed surfaces (i.e., a primary measure of impact reduction). More specifically, the deflector of width (Ydef) 2 m with an inclination of (∅def) 65° was the most effective, where the shear stress on the pile surface and the emission factor were reduced by 29.16% and 21.79%, respectively, compared to the single fence of the same height. Finally, adding dynamic wind deflectors enhances the performance of solid fences, and it is a more effective and less expensive solution than replacing single fences with other windbreak models.
