王勇杰,蒋昌波,邓斌.风作用下孤立波在珊瑚礁上传播变形机制数值模拟研究[J].海洋通报,2022,(6): |
风作用下孤立波在珊瑚礁上传播变形机制数值模拟研究 |
Numerical simulation of solitary waves transformation over coral reefs under wind |
投稿时间:2021-11-29 修订日期:2022-03-04 |
DOI:10.11840/j.issn.1001-6392.2022.06.004 |
中文关键词: 两相流 数值模拟 风 孤立波 珊瑚礁 波浪破碎 |
英文关键词:Two-phase flow numerical simulation wind solitary wave coral reefs waves breaking |
基金项目:国家自然科学基金 ( 51839002;51979015;51879015 ),湖南省自然科学基金资助项目(2021JJ30707) |
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中文摘要: |
基于二维不可压缩两相流模型建立了数值风浪水槽,采用SST k-ω雷诺时均湍流模型,研究了风作用下孤立波在珊瑚礁上的传播变形规律。将计算结果与实验数据对比,证明了该两相流模型计算孤立波在珊瑚礁上传播的准确性,并进一步分析了不同风速对珊瑚礁上孤立波传播变形的影响。结果表明:风的作用会使波面发生随机脉动特征。当地波高随风速的增大而增大;当地波高关于风速的变化梯度随入射波高的增大而增大。风的作用会加快孤立波的传播并且使孤立波提前发生破碎;孤立波开始破碎的位置随风速的增大向远离礁坪的方向移动。反射系数随风速的增大而增大;反射系数关于风速的变化梯度随入射波高的增大而减小;透射系数随风速的增大呈增大趋势。平底区波峰剖面同一水深处的水平流速随风速的增大而增大;且一定的风速不改变水平流速沿水深的变化梯度。有风时波面上方的矢量密度和大小均明显高于无风时且与风速呈正相关,并且波峰上方气流不再循环。随着风速的增大,水气交界面附近的正涡量和负湍流剪应力减小,负涡量和正湍流剪应力增大。水体动能、势能和总能达到高值的时间随风速的增大而减少;水体动能、势能和总能随风速的增大而增大,并且风速对水体动能的相对影响大于势能。 |
英文摘要: |
A numerical wind wave flume was established based on the two-dimensional incompressible two-phase flow model, and solitary waves transformation on coral reefs under wind effects was studied by using the standard SST k-ω Reynolds time-averaged turbulence model. Comparing the calculated results with the experimental data, it is proved that the two-phase flow model is accurate in calculating solitary waves transformation on coral reefs, and the influence of different wind speeds on solitary waves transformation on coral reefs is analyzed. The results show that the effect of wind will cause the wave surface to have random pulsation characteristics. The local maximum wave height increases with the increase of wind speed. The variation gradient of the local maximum wave height with respect to the wind speed increases with the increase of the incident wave height. The effect of wind will accelerate the propagation of solitary waves and make solitary waves breaking in advance. The position of solitary waves breaking moves away from the reef flat with the increase of wind speed. The reflection coefficient increases with the wind speed. The variation gradient of the reflection coefficient with respect to the wind speed decreases with the increase of the incident wave height. The transmission coefficient increases with the increase of wind speed. In the flat bottom, the horizontal velocity at the same water depth of the wave crest profile increases with the increase of wind speed, and a certain wind speed does not change the gradient of horizontal velocity along the water depth. The vector density and magnitude above the wave surface with wind are obviously higher than those without wind and it is positively correlated with wind speed, and the airflow above the crest no longer circulates. With the increase of wind speed, the positive vorticity and negative turbulent shear stress near the water-air interface decrease, while the negative vorticity and positive turbulent shear stress increase. The time for the kinetic energy, potential energy and total energy of waves to reach high values decreases with the increase of wind speed. The kinetic energy, potential energy and total energy of waves increase with the increase of wind speed and the relative influence of wind speed on the kinetic energy of waves is greater than that of potential energy. |
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