CFD flow dynamics over model scarps and slopes
CFD flow dynamics over model scarps and slopes
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DOI：
10.1080/02723646.2019.1706215
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发表时间：
2019-12
影响因子：
1.6
通讯作者：
P. Hesp;T. Smyth
中科院分区：
文献类型：
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作者：
P. Hesp;T. Smyth
沙丘陡坎上的风流知识，以及陡坎填充后的各种坡度，对于理解从海滩到沙丘的沉积物输运路径是很重要的。在本研究中，对陡坎（也称为前向台阶）上的水流进行了审查，并通过CFD建模检查了垂直陡坎（90°）和三个坡度（45°、24°和14°，均为2 m高）上的水流。本文研究了在三种斜向入射风作用下，三个90°陡坎（高度分别为1，2，4m）和一个2m高的垂直陡坎（90°）上的气流。坡度越小，气流减速和分离的程度越小，最大气流分离和反向涡的发展出现在垂直陡坎上。山顶风流分离的程度在陡坎处最大，在45°坡度处小得多。随着陡坎高度的增加，湍流的空间范围、风速和气流分离区的范围也增加。当入射风的方向在垂直悬崖上变得更加倾斜时，会发生更少的减速，螺旋涡取代了滚柱涡。我们的研究结果表明，悬崖形态和风向可能会影响运输途径。图形摘要
ABSTRACT Knowledge of wind flow over dune scarps and, as scarps fill, their subsequent various slopes, is important for understanding sediment transport pathways from beach to dunes. In this study, flow over scarps (also termed forward-facing steps) is reviewed, and the flow over a vertical scarp (90°) and three slopes of 45°, 24°, and 14°, all 2 m in height, is examined via CFD modelling. The flow over three 90° scarps, with heights of 1 m, 2 m and 4 m, and over a 2-m high vertical (90°) scarp for three oblique incident winds is studied. The extent of wind flow deceleration and separation becomes smaller with decreased slope, with maximum flow separation and reverse vortex development occurring on the vertical scarp. The extent of crest wind flow separation is greatest for the scarp and considerably less for the 45° slope. As scarp height increases, so too does the spatial extent of turbulent wind flow, wind speed, and extent of the flow separation region. As incident wind direction became more oblique over a vertical scarp, less deceleration occurs, and helicoidal vortices replace roller vortices. Our results demonstrate how scarp morphology and wind direction are likely to influence transport pathways. Graphical Abstract