Jet flow over foredunes
Jet flow over foredunes
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DOI：
10.1002/esp.3945
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发表时间：
2016-09
影响因子：
3.3
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
喷射流是表现出高速最大值的局部流，在自然界和许多装置中相对常见。它们只是偶尔在沙丘上被观察到，它们的动力学知之甚少。本文探讨了计算流体动力学（CFD）的二维（2D）模拟射流在前沙丘地形。从向岸（0°）到高度倾斜的沿岸（70°）入射风接近角，以10°增量模拟气流。计算流体动力学模型表明，射流的形成不依赖于临界风速，入射风速的增加不会影响射流的大小。首先在爱德华王子岛前沙丘形态的例子检查约1.0米的前沙丘顶部向海形成射流。当入射风来自大于~50°的斜进近角时，不会形成射流，因为在该入射角下，穿过低得多的斜坡的气流加速度明显较小。陡坎的存在确实会影响波峰射流的结构，因为在存在陡坎的地方，射流更加明显。表面粗糙度影响射流膨胀的幅度和射流更好地开发裸露的表面相比，植被的。版权所有© 2016约翰威利父子有限公司.
Jet flows, which are localized flows exhibiting a high speed maxima, are relatively common in nature, and in many devices. They have only been occasionally observed on dunes, and their dynamics are poorly known. This paper examines computational fluid dynamic (CFD) two‐dimensional (2D) modelling of jet flow over a foredune topography. Flow was simulated in 10° increments from onshore (0°) to highly oblique alongshore (70°) incident wind approach angles. CFD modelling reveals that the formation of a jet is not dependent on a critical wind speed, and an increase in incident wind velocity does not affect the magnitude of jet flow. A jet is first formed at ~1.0 m seawards of the foredune crest on the Prince Edward Island foredune morphology example examined here. A jet is not developed when the incident wind is from an oblique approach angle greater than ~50° because there is significantly less flow acceleration across a much lower slope at this incident angle. The presence of a scarp does influence the structure of the crest jet, in that the jet is more pronounced where a scarp is present. Surface roughness affects the magnitude of jet expansion and jets are better developed on bare surfaces compared to vegetated ones. Copyright © 2016 John Wiley & Sons, Ltd.