通过波浪水槽实验对大糙率礁面存在下珊瑚礁海岸附近规则波非线性特征参数(偏度、不对称度和厄塞尔数)的变化规律进行了研究。实验采用圆柱体阵列来模拟礁面的粗糙度,测试了一系列规则波工况。结果表明:偏度、不对称度和厄塞尔数的幅值分别在珊瑚礁破碎带结束位置、破碎带内和破碎带开始位置达到最大。3个参数的幅值均随着入射波波高的增大而增大;偏度值随着波浪周期的增大而减小,不对称度幅值和厄塞尔数随着周期的增大而增大;偏度值随着礁坪水深的增大而增大,不对称度幅值和厄塞尔数随着礁坪水深的增大而减小。深水厄塞尔数可以用来描述礁坪上波浪非线性参数的变化,最后给出了用其预测礁坪上3个非线性特征参数的经验关系式。
Abstract
To investigate monochromatic wave nonlinear characteristics around coral reefs with large surface roughness, laboratory experiments were carried out in a wave flume. A cylinder array was used to model the reef roughness and a series of monochromatic wave conditions were tested. Results show that magnitudes of the wave skewness, the wave asymmetry and the Ursell Number reach their peaks at the endpoint, in the interior and at the stating location of the reef surf zone, respectively. All the three parameters increase with the increasing wave height. Meanwhile, the skewness decreases with the increase of wave period while both the asymmetry and the Ursell Number increase with the increase of wave period. Moreover, the skewness increases with the increase of reef-flat water level while both the asymmetry and the Ursell Number decrease with the increase of reef-flat water level. The deep-water Ursell Number is able to describe the variations of the three examined parameters on the reef flat, and the empirical formulas are finally proposed in this study to predict these parameters.
关键词
礁面糙率 /
规则波 /
偏度 /
不对称度 /
厄塞尔数
Key words
reef roughness /
monochromatic waves /
skewness /
asymmetry /
Ursell Number
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基金
国家自然科学基金项目资助 (51979013, 51679014);长沙理工大学研究生科研创新项目资助 (CX2019SS15)
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