Local impact of dust storms around a suburban building in arid and semi-arid regions: numerical simulation examples from Dubai and Riyadh, Arabian Peninsula

摘要

Dust storms are common in arid and semi-arid regions, e.g., the Arabian Peninsula, where undisturbed wind can either weather the rocks and transport the grains for kilometers over the landscape or even overseas, or form dunes and ripples. We used a multiphase Eulerian-Lagrangian computational fluid dynamics model to investigate the impact of dust storms in the form of density current on a 10 x 10-m building. This numerical investigation particularly applies to the suburbs of metropolis, consisting of peripheral neighborhoods of meter-scale buildings that, as suggested by our results, can strongly affect the path of the storm before impacting the Downtown. Our results of flow-building interaction on pulsating (CASE 1) versus sustained (CASE 2, reference) and long-lived (CASE 3) storm show a strong amplification of flow dynamic pressure up to a factor of about 14 in streamwise direction and a heavy grain accumulation of about 800 kg around the building. With respect to reference sustained storm, the results show a more intense pressure amplification up to about 12 for slower (CASE 4) or coarser (CASE 5) storm, but a less intense amplification up to about 3 for more dilute storm (CASE 6) in transverse direction. Maximum grain accumulation around the building is of about 4,300 kg (55 % is on building front) for coarser storm, whereas high fog in the building rear occurs for more dilute storm. These results can be useful when assessing the impact of dust storms against buildings.