Authors

Abstract

Aeolian sand transport is a key driver of desertification; however, accurately modeling particle–fluid interactions remains challenging. Many existing numerical simulations assume spherical grains, which can introduce systematic errors in transport predictions. To address this limitation, a CFD–DEM framework incorporating superquadric particles was developed, enabling a more realistic representation of grain geometry. Simulations were conducted at wind speeds of 9, 12, and 15 m/s, with systematic variations in particle axis ratio and shape parameters, and the results were validated against wind tunnel experiments. The results reveal a clear hierarchical control of aeolian transport dynamics. Wind speed dominates transport intensity and temporal evolution. The particle axis ratio exerts the primary influence on streamwise transport, producing variations of up to 96% in mean particle velocity, whereas shape parameters induce smaller changes of approximately 53%. In contrast, particle shape parameters govern vertical transport behavior, causing velocity variations of up to 91.6%, compared with less than 74.4% attributable to axis ratio effects. Moreover, the influence of shape parameters weakens with increasing wind speed, with maximum variations of 83%, 67%, and 59% at wind speeds of 9, 12, and 15 m/s, respectively. This study enhances the accuracy of wind-sand transport simulations and contributes to improved predictions of wind-driven sand impacts on soil, crops, and water resources in farmland. The improved simulations provide scientific support for agricultural wind and sand control and ecological restoration, promoting sustainable agricultural development and mitigating the negative effects of desertification.

Abstract in Chinese

风沙输运是荒漠化的主要驱动因素，但颗粒–流体相互作用的建模仍然具有挑战性。许多现有模拟假设沙粒为球形，这可能在输运预测中引入系统性误差。为克服这一局限，我们开发了一种结合超二次曲面颗粒的 CFD–DEM 框架，从而能够更真实地表征沙粒几何形态。模拟在 9、12 和 15 m/s 的风速下进行，系统考察了轴比和形状参数的变化，并通过风洞实验进行了验证。结果表明，输运动力学存在明显的分层控制效应。风速主导了输运强度和时间演化。轴比在顺风方向上起主要作用，平均速度变化幅度高达 96%；而形状参数的影响相对较小，约为 53%。相反，在垂直输运中，形状参数起决定性作用，速度变化幅度高达 91.6%，而轴比的影响小于 74.4%。随着风速增加，形状参数的影响逐渐减弱，在 9、12 和 15 m/s 下的最大变化分别为 83%、67% 和 59%。这项研究提高了风沙输送模拟的精度，帮助更好地预测风沙对农田土壤、作物和水资源的影响。改进的模拟为农业风沙控制和生态恢复提供了科学支持，推动可持续农业发展，并减轻沙漠化的负面影响。