Abstract Compared with longer-crested linear dunes formed in the bimodal wind regime, little is known about the driving forces of linear dunes that elongate in the lee side of obstacles under a unimodal wind regime. Here, we present the flow dynamics and sand deposition patterns around the aligned nebkhas with different spacing distances (∆) based on computational fluid dynamics (CFD) simulation, wind tunnel experiment and field measurement. In terms of the relationships between the width of horseshoe vortex around two laterally aligned nebkhas (T1 and T2, respectively) and ∆, four wake flow patterns were identified: distinctly merged wake flow when ∆ → 0, merging flow when 0

中文翻译：

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Nebkha 路线及其对单峰风况下阴影沙丘伸长的影响

摘要 与双峰风况下形成的长顶线状沙丘相比，单峰风况下在障碍物背风侧伸长的线状沙丘的驱动力知之甚少。在这里，我们基于计算流体动力学 (CFD) 模拟、风洞实验和现场测量，展示了具有不同间距 (Δ) 的对齐 nebkhas 周围的流动动力学和砂沉积模式。根据两个横向对齐的nebkhas（分别为T1和T2）周围的马蹄形涡旋宽度与Δ之间的关系，确定了四种尾流模式：Δ→0时明显合并的尾流，0时合并流