Nonlinear wave generation by a wavemaker in deep to intermediate water depth
Nonlinear wave generation by a wavemaker in deep to intermediate water depth
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造波机在深水至中水深度产生非线性波浪
DOI：
10.1016/j.oceaneng.2019.04.065
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发表时间：
2019
影响因子：
5
通讯作者：
L. Shemer
中科院分区：
文献类型：
--
作者：
A. Khait;L. Shemer
本文提出了一种新的解析方法来计算精确产生陡波所需的造波运动的非线性修正。它是利用现有的非线性水波模型，如Zakharov方程、Dysthe方程或Schrödinger方程发展起来的。该方法在非线性阶数和频谱宽度方面的局限性是由所使用的波浪模型决定的，从而允许它扩展到三阶或更高阶，超出了现有造波理论的限制。非线性水波模型的应用大大简化了对造波机驱动信号进行非线性校正的确定过程。所提出的方法与Schäffer理论、完全非线性数值模拟和波浪水槽实验进行了仔细的验证。利用该方法的优点，仔细研究了不同的波浪产生模式。线性传递函数的实际值与理论预测值之间存在明显的偏差，这与早期的实验研究结果一致。由造波面的有限位移引起的二阶平均电流被认为是造成这种偏差的原因之一。
A new analytical method to calculate the nonlinear correction to the wavemaker motion needed for the accurate generation of steep waves is suggested. It is developed taking advantage of the existing models of nonlinear water waves, such as Zakharov, Dysthe, or Schrödinger equations. The limitations of the method in terms of the order of nonlinearity and spectral width are determined by the wave model used, thus allowing its extension to the 3rdand higher orders, beyond the limits of the existing wavemaker theories. Application of the nonlinear water waves models allowed significant simplification of the procedure of determination of the nonlinear correction to the wavemaker driving signal. The suggested method was carefully validated against the theory of Schäffer, fully-nonlinear numerical simulations and wave flume experiments. The advantages of the method were exploited to carefully investigate different regimes of wave generation. An appreciable deviation of the actual value of the linear transfer function from the theoretical predictions was found in agreement with the earlier experimental investigations. The mean current arising at the 2ndorder due to finite displacements of the wavemaker surface was suggested as one of the reasons for that deviation.