Three‐dimensional antidunes coexisting with alternate bars
Three‐dimensional antidunes coexisting with alternate bars
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三维反沙丘与交替沙坝共存
DOI：
10.1002/esp.4938
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发表时间：
2020
影响因子：
3.3
通讯作者：
Otsuka Junichi
中科院分区：
文献类型：
--
作者：
Inoue Takuya;Watanabe Yasunori;Iwasaki Toshiki;Otsuka Junichi
反沙丘是在具有超临界水流的河流中形成的河流河床。反沙丘上的水面与河床表面强烈同相，水面被放大以产生大的表面波。许多实验研究都涉及到了反沙丘；然而，在有交替沙洲的宽阔河道中，三维反沙丘的形状还没有得到适当的了解。在这项研究中，我们对大宽深比条件下反沙丘的纵向和横向长度尺度进行了实验研究。我们的实验结果为反沙丘和自由交替沙洲的共同演化提供了证据，并首次表明自由沙洲的发展极大地改变了反沙丘上水面波的三维形状。在宽航道中没有自由沙洲的情况下，会形成多个纵波列，且横向波列数随宽深比的增大而增加。然而，自由杆的存在影响了局部流动特性，导致横向波列数的减少。因此，我们结合前人关于反沙丘和自由沙洲的两种理论，提出了一个预测波浪列数减少的简单模型。由该模型得到的结果与实验观测结果基本一致。©2020作者。约翰·威利父子有限公司出版的地球表面过程和地貌
Antidunes are fluvial bedforms that form in rivers with supercritical flows. The water surface over antidunes is strongly in phase with the bed surface, and the water surface is amplified to produce large surface waves. Many experimental studies have addressed antidunes; however, the shapes of three‐dimensional antidunes in a wide channel with alternate bars have not yet been appropriately understood. In this study, we experimentally investigated the streamwise and transverse length scales of antidunes under conditions with a large width–depth ratio. Our experimental results provide evidence for the coevolution of antidunes and free alternate bars, and show for the first time that the development of free bars greatly alters the three‐dimensional shape of water surface waves over antidunes. In the absence of free bars in a wide channel, multiple longitudinal wave trains form, and the number of wave trains counted in the transverse direction increases with increases in the width–depth ratio. However, the presence of free bars affects the local flow characteristics, resulting in a decrease of the number of wave trains in the transverse direction. Therefore, we propose a simple model for predicting the reduction in the number of wave trains by combining two previous theories for antidunes and free bars. Results obtained by the model were found to largely agree with experimental observations. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd
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影响因子：
--
作者：
J. Venditti
通讯作者：
J. Venditti
影响因子：
3.3
作者：
D. Chatterjee;S. Ghosh;B. S. Mazumder;K. Sarkar
通讯作者：
K. Sarkar
涟漪和沙丘上的流动力学
影响因子：
--
作者：
J. Nelson;J. Smith
通讯作者：
J. Smith
对沙丘的思考：细砾石中的反沙丘过渡
DOI：
--
发表时间：
2002
期刊：
影响因子：
--
作者：
P. Carling;A. Shvidchenko
通讯作者：
A. Shvidchenko
影响因子：
3.3
作者：
R. Weichert;G. R. Bezzola;H. Minor
通讯作者：
R. Weichert;G. R. Bezzola;H. Minor