Modeling the Inhibition Effect of Straw Checkerboard Barriers on Wind-blown Sand
- 1School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, PR China
- 2MOE Engineering Research Center of Desertification and Blown-sand Control, Beijing Normal University, Beijing, PR China
- 3College of Mechanics and Materials, Hohai University, Nanjing, Jiangsu 211000, PR China
Abstract. Straw checkerboard barriers (SCBs) are usually laid to prevent or delay the process of desertification caused by aeolian sand erosion in arid and semi-arid regions. Understanding the impact of SCBs and its laying length on aeolian sand erosion is of great significance to reduce the damage and the laying costs. In this study, a three-dimensional wind-blown sand model in presence of SCBs was established by introducing the splash process and equivalent sand barriers into a large-eddy simulation airflow. From this model, the inhibition effect of SCBs on wind-blown sand was studied qualitatively, and the sensitivity of aeolian sand erosion to the laying length was investigated. The results showed that the wind speed in the SCBs area decreases oscillatively along the flow direction. Moreover, the longer the laying lengths, the lower the wind speed in the stable stage behind SCBs, and the lower the sand transport rate. We further found that the concentration of sand particles near the side of SCBs is higher than that in its central region, which is qualitatively consistent with the previous research. Our results also indicated that whether the wind speed will decrease below the impact threshold or the fluid threshold is the key factor affecting whether sand particles can penetrate the SCBs and form stable wind-blown sand behind the SCBs under the same conditions. Our research can provide theoretical support for the minimum laying length of SCBs in anti-desertification projects.
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