CFD simulation of the wind field over a terrain with sand fences: Critical spacing for the wind shear velocity

Lima, Izael A.; Parteli, Eric J. R.; Shao, Yaping; Andrade, José S.; Herrmann, Hans J.; Araújo, Ascânio D.

doi:10.1016/j.aeolia.2020.100574

Cited by 26 publications

(8 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Relevant studies show that sand transported by the wind accumulates around any type of obstacle [ 24 , 25 ], and the decrease in near-surface wind speed easily causes sand material accumulation, while the increase in wind speed easily causes blown sand flow erosion [ 26 , 27 , 28 , 29 ]. In the wind-speed-weakening area upwind, because the wind-speed-weakening range and intensity of the bridge were smaller than those of the subgrade, the range and intensity of sand material accumulation upwind of the bridge were smaller than those of the subgrade.…”

Section: Cause Analysismentioning

confidence: 99%

Characteristic Differences of Wind-Blown Sand Flow Field of Expressway Bridge and Subgrade and Their Implications on Expressway Design

Xie

Zhang

Pang

2022

Sensors

View full text Add to dashboard Cite

Bridges and subgrades are the main route forms for expressways. The ideal form for passing through sandy areas remains unclear. This study aims to understand the differences in the influence of expressway bridges and subgrades on the near-surface blown sand environment and movement laws, such as the difference in wind speed and profile around the bridge and subgrade, the difference in wind flow-field characteristics, and the difference in sand transport rate, to provide a scientific basis for the selection of expressway route forms in sandy areas. Therefore, a wind tunnel test was carried out by making models of a highway bridge and subgrade and comparing the environmental effects of wind sand on them. The disturbance in the bridge to near-surface blown sand activities was less than that of the subgrade. The variation ranges of the wind speed of the bridge and its upwind and downwind directions were lower than those of the subgrade. However, the required distance to recover the wind speed downwind of the bridge was greater than that of the subgrade, resulting in the sand transport rate of the bridge being lower than that of the subgrade. The variation in the wind field of the subgrade was more drastic than that of the bridge, but the required distance to recover the wind field downwind of the bridge was greater than that of the subgrade. In the wind speed-weakening area upwind, the wind speed-weakening range and intensity of the bridge were smaller than those of the subgrade. In the wind speed-increasing area on the top of the model, the wind speed-increasing range and intensity of the bridge were smaller than those of the subgrade. In the wind-speed-weakening area downwind, the wind speed weakening range of the bridge was greater than that of the subgrade, and the wind speed-weakening intensity was smaller than that of the subgrade. This investigation has theoretical and practical significance for the selection of expressway route forms in sandy areas.

show abstract

Section: Cause Analysismentioning

confidence: 99%

Characteristic Differences of Wind-Blown Sand Flow Field of Expressway Bridge and Subgrade and Their Implications on Expressway Design

Xie

Zhang

Pang

2022

Sensors

View full text Add to dashboard Cite

show abstract

“…Fences were widely installed to restore the grassland ecosystem by prevent livestock from foraging and trampling during the implementation of fencing project (Du et al, 2020). Unlike traditional fences to directly control wind erosion (Lima et al, 2020; Zhang et al, 2023), they could result in the increase of grass cover, species biodiversity and biomass (Wu et al, 2009) and improvement of soil physicochemical properties (Du et al, 2020), which strengthen soil resistance ability to wind erosion (Cheng et al, 2020; Toure et al, 2019). This project in the alpine grassland of Tibet covers an area of more than 6 million hectares completed from 2004 to 2013, with an investment of more than 2.5 billion RMB (Lu et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Effects of fencing project on wind erosion reduction in Alpine grassland and its impact on the development of climbing dunes in southern Tibetan Plateau

Liu,

Yuan,

Xiong

et al. 2024

Earth Surf Processes Landf

View full text Add to dashboard Cite

Alpine grassland in the Tibetan Plateau (TP) of China is one of the most susceptible regions to wind erosion in recent decades. The fencing project, grassland enclosure using fencing, has been a common strategy for land degradation counteraction in the TP. However, the wind erosion reduction effects of fencing project remain largely unclear, especially in the regions lacking continuous observations such as Southern TP. In this study, a sand source area with fencing protection (fencing land, a mainly eroded grazing grassland before being fenced) and a near‐source climbing dune were selected to illustrate the effect of fencing project on wind erosion using 137Cs and 210Pbex tracing techniques. An adjacent perennial grazing land was selected for comparison. The results showed that the wind erosion rate in sand source area was 17.18 t·ha−1·year−1 before the implementation of project, while that was −6.67 t·ha−1·year−1 since fencing. The wind erosion rates in perennial grazing land were 24.91 t·ha−1·year−1 for 20 years ago to 1963 and 24.33 t·ha−1·year−1 for almost 20 years. The normalized difference vegetation index (NDVI) of sand source area increased from 0.098 before fencing to 0.137 after fencing; the latter was 1.63 times higher than that of grazing land during the same period. After the implementation of fencing project in sand source area, it was found that the sand supply to the climbing dune was mainly reduced, thus stabilizing it and promoting NDVI increase, especially in the middle‐lower part of the climbing dune. These results would benefit the evaluation of grassland restoration effectiveness in the TP.

show abstract

“…Common types of sand fence design-types include horizontal, upright, holed-plank, griddled, and wind-screened fences (Dong et al, 2007). The aerodynamic properties and sheltering effects of sand fences depend mainly on their geometric design and multiple design factors, including height, length, width, porosity, opening size/shape/distribution, and row numbers and the spacing between rows (Li and Sherman, 2015;Lima et al, 2020;Xin et al, 2021). The sheltering effect of multiple rows of sand fences is commonly considered to be more efficient than that of a single-row sand fence (Fang et al, 2018;Liu et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, early studies indicated that sand fences with sharp edges (e.g., square holes, vertical slits, or horizontal slits) have higher sand-trapping efficiencies than those with round edges (e.g., circular holes) (Richards et al, 1984). Height is another important structural parameter of sand fences and is critical for determining sand trapping efficiency and the magnitude of dune deposition (Lima et al, 2020;Ning et al, 2020;Xin et al, 2021). To trap as many transported particles as possible, fence heights usually exceed the saltation height of the wind-blown sand (Phillips and Willetts, 1979).…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic Properties and Shelter Effects of a Concrete Plate-Insert Sand Fence Along the Lanzhou-Xinjiang High-Speed Railway in Gobi Regions Under Strong Winds

Wang

Niu

et al. 2022

Front. Environ. Sci.

View full text Add to dashboard Cite

The Lanzhou-Xinjiang High-Speed Railway runs through high-wind areas in the Gobi Desert, and disasters arising from the effects of blown sand critically endanger the safety of railway operations. To prevent sand deposition on the rail bed, double rows of sand fences composed of concrete columns and plates are installed on the windward side of the railway line. However, the aerodynamic properties and sheltering effects of these fences remain unclear. In this study, the effects of sand fences on boundary wind patterns and sand transport were investigated in the field and in a wind tunnel. The following results were obtained: 1) The wind velocity was efficiently reduced on the leeward side of the first and second rows of fences by 78% and 87%, respectively. Nevertheless, owing to large openings in the fence, the sand-trapping efficiencies of the first and second rows of fences on the leeward sides were only 72 and 63%, respectively. 2) The effective shelter distance (Ds) of the fence is 10 times the height of the fence; however, the horizontal distance between the two rows of fences is much larger than the Ds of the fence. This allows the wind velocity between the fences to rise above the saltation threshold once again, thereby reducing the overall sheltering effects of the double-row of fences. This study will produce a theoretical reference for improving the design and installation of blown-sand control systems in the strong-wind regions of the Gobi.

show abstract

CFD simulation of the wind field over a terrain with sand fences: Critical spacing for the wind shear velocity

Cited by 26 publications

References 82 publications

Characteristic Differences of Wind-Blown Sand Flow Field of Expressway Bridge and Subgrade and Their Implications on Expressway Design

Characteristic Differences of Wind-Blown Sand Flow Field of Expressway Bridge and Subgrade and Their Implications on Expressway Design

Effects of fencing project on wind erosion reduction in Alpine grassland and its impact on the development of climbing dunes in southern Tibetan Plateau

Aerodynamic Properties and Shelter Effects of a Concrete Plate-Insert Sand Fence Along the Lanzhou-Xinjiang High-Speed Railway in Gobi Regions Under Strong Winds

Contact Info

Product

Resources

About