Laboratory study of solitary-wave transformation over bed-form roughness on fringing reefs
Laboratory study of solitary-wave transformation over bed-form roughness on fringing reefs
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DOI：
10.1016/j.coastaleng.2013.05.002
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发表时间：
2013-10
影响因子：
4.4
通讯作者：
P. Quiroga;K. Cheung
中科院分区：
文献类型：
--
作者：
P. Quiroga;K. Cheung
本文介绍了一系列二维水槽试验的制定和实施，以调查床面粗糙度对海岸波浪过程的影响。实验是在俄勒冈州州立大学的一个长104米、高4.6米的水槽中进行的。礁模型有1：12的正面坡度和一个长的平坦部分，用于检查波浪变浅和破碎以及钻孔形成和传播。该模型高2.36米，水深范围从2.36米到2.66米，以产生干和湿的珊瑚礁条件。床面粗糙度是由木梁横跨水槽放置在四个配置不同的高度从0.038到0.076米和间距从0.388到0.768米，以提供一个范围内的间距比从5到20。入射孤立波的高度从水深的10%到50%不等，以涵盖破碎和非破碎条件的范围。一系列的金属丝和声波测量仪测量了波浪沿着水槽的变化，一台数码相机记录了水槽壁上画的背景网格上破碎波浪的图像。底床形状减小了波传播的有效深度，并改变了自由表面流的结构。与素混凝土表面的对照实验相比，孤立波在礁坡上破碎更早，耗散的能量更多。随后的钻孔在浅水礁滩上随着波动而减慢，但在深水中由于更有活力的流动而加快。
This paper presents the formulation and implementation of a series of two-dimensional flume experiments to investigate effects of bed-form roughness on coastal wave processes. The experiments were carried out on a fringing reef model in a 104-m long and 4.6-m high flume at Oregon State University. The reef model has a 1:12 face slope and a long flat section for examination of wave shoaling and breaking as well as bore formation and propagation. The model is 2.36 m tall and the water depth ranges from 2.36 to 2.66 m to produce dry and wet reef conditions. The bed-form roughness is modeled by timber beams placed across the flume in four configurations by varying the height from 0.038 to 0.076 m and the spacing from 0.388 to 0.768 m to provide a range of pitch ratios from 5 to 20. The incident solitary wave height varies from 10 to 50% of the water depth to cover a range of breaking and non-breaking conditions. A series of wire and sonic gauges measured the wave transformation along the flume and a digital camera recorded images of the breaking waves on a background grid painted on a flume wall. The bed forms decrease the effective depth for wave propagation and modify the structure of the free surface flow. In comparison to a control experiment with plain concrete surface, the solitary wave breaks earlier and dissipates more energy on the reef slope. The subsequent bore slows down with undulation over the shallow reef flat, but speeds up for more energetic flows in deeper water.