Abstract Wind-blown sand induces serious desertification and consequently results in financial loss. Grain-bed interaction processes are primary responsible for sand saltation, which are generally described using a splash function. However, current splash functions are designed for horizontal beds although almost all sand surfaces are sloped (e.g., sand ripples and dunes), leading to the possibility of the predicted sand flux over a slope being several times higher than the observed flux. Herein, a three-dimensional splash function for a sloped bed that reasonably describes grain-bed interactions is proposed. The modified sloped bed splash function is introduced into a fluid-solid-coupled large-eddy simulation model, with which the wind-blown sand moments over various slope beds could be exactly reproduced. Simulation results show that the sediment transport mass flux on the uphill exhibited a nearly cubic dependence with the friction velocity, while that on the downhill showed an intermediate relationship between quadratic- and cubic-dependence. This research provides a useful approach for investigating natural aeolian sand movements.

中文翻译：

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砂跃变斜床飞溅函数的改进

摘要 风沙造成严重的荒漠化，造成经济损失。粒床相互作用过程是沙子跃迁的主要负责人，通常使用飞溅函数来描述。然而，目前的飞溅函数是为水平床设计的，尽管几乎所有的沙面都是倾斜的（例如，沙波纹和沙丘），导致斜坡上预测的沙流量比观察到的流量高几倍的可能性。在此，提出了一种合理描述颗粒床相互作用的倾斜床的三维飞溅函数。将修正后的斜床飞溅函数引入流固耦合大涡模拟模型中，可以准确再现各种斜床风沙力矩。模拟结果表明，上坡的泥沙输运质量通量与摩擦速度呈近三次方相关性，而下坡的泥沙输运质量通量呈二次方和三次方相关性。这项研究为调查自然风沙运动提供了一种有用的方法。