Experimental Study of Wave‐Induced Longitudinal Vortices
Experimental Study of Wave‐Induced Longitudinal Vortices
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DOI：
10.1061/(asce)0733-9429(1991)117:12(1639
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发表时间：
1991-12
影响因子：
2.4
通讯作者：
H. Nepf;S. Monismith
中科院分区：
文献类型：
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作者：
H. Nepf;S. Monismith
人们经常观察到河口、湖泊和海洋中的风驱动流包含强烈的纵向涡流，称为朗缪尔环流。为了通过实验测试克雷克和莱博维奇提出的理论，即这些细胞是通过波流相互作用产生的，我们将机械产生的波叠加在湍流通道流上。我们的结果表明，流向涡旋可以通过 Craik 和 Leibovich 描述的波流相互作用形成：平均涡度的垂直分量可以通过波浪的剪切斯托克斯漂移流旋转，从而产生纵向涡度。在本配置中，垂直涡度的主要来源是通道侧面的边界层。尽管如此，鉴于此类纵向涡流增强了混合，我们的实验表明波流相互作用可以对许多水体中的近地表混合做出重大贡献。因此，科伊勒根和布拉姆试图建立波与混合之间的联系……
Wind‐driven currents in estuaries, lakes, and the ocean are often observed to include strong longitudinal vortices, known as Langmuir cells. To test experimentally the theory developed by Craik and Leibovich that these cells arise through wave‐current interactions, we superimposed mechanically generated waves on a turbulent channel flow. Our results show that streamwise vortices can form through wave‐current interaction described by Craik and Leibovich: The vertical component of the mean vorticity can be rotated by the sheared Stokes' drift current of the waves to produced longitudinal vorticity. In the present configuration, the main sources of vertical vorticity are the boundary layers on the sides of the channel. Nonetheless, given the fact that longitudinal vortices like these enhance mixing, our experiments suggest that wave‐current interactions can contribute significantly to near‐surface mixing in many water bodies. Thus, the connection between waves and mixing that Keulegan and Brame sought to mak...