This paper provides the experimental validation of the generalized second-order three-dimensional (3D) coupling theory outlined by Yang et al. [Z. Yang, S. Liu, X. Ji, and H.B. Bingham, 2020. A generalized second-order 3D theory for coupling multidirectional nonlinear wave propagation from a numerical model to a physical model. Part I: Derivation, implementation and model verification, submitted for publication] using multidirectional nonlinear 3D irregular waves. Based on the second-order theory for two-dimensional (2D) irregular waves described by Yang et al. (2014a), this work provides a second-order dispersive correction for the physical wavemaker signal which improves the nonlinear 3D wave information transfer between the numerical and physical models compared to the first-order method of Zhang et al. (2007). The important coupling equation and its discretization schemes were presented in detail in Part I. For further validating the performance of the second-order 3D coupling model under complex waves and bathymetry conditions, in this Part II, a careful experimental validation has been carried out by establishing a flat coupling basin and a concave-convex coupling basin. In addition, a sequence of progressively more complex numerical target waves has been used and an I-shaped segmented piston-type wavemaker system has been considered for verification of the theory. The effectiveness, adaptability, and precision of the second-order 3D coupling model have been discussed in detail. The effects of the wave parameters and its nonlinearity on the coupling simulation have also been evaluated from the discrepancy error and a wave harmonic analysis. By defining a space synchronization error, the overall error of the spatial wave field has been analyzed. Coupling simulation experiments using oblique regular and irregular waves, unidirectional irregular waves, and multidirectional irregular waves show that the traditional first-order coupling model has limitations when coupling complex waves with strong nonlinearity. When controlling the waves using the second-order 3D coupling signal, the higher harmonics underlying the numerical waves are accurately captured and transferred into the physical model, and the unwanted second-order spurious free waves are substantially reduced. Results obtained from the experimental verification described in this paper demonstrate the strengths of the second-order 3D coupling theory, which are more evident with increased wave nonlinearity.

本文提供了Yang等人概述的广义二阶三维（3D）耦合理论的实验验证。[Z. Yang，S。Liu，X。Ji和HB Bingham，2020年。一种通用的二阶3D理论，用于将多向非线性波传播从数值模型耦合到物理模型。第一部分：使用多向非线性3D不规则波的推导，实现和模型验证，已提交出版。Yang等人基于二维（2D）不规则波的二阶理论。（2014a），这项工作为物理造波器信号提供了二阶色散校正，与张等人的一阶方法相比，改善了数值模型和物理模型之间的非线性3D波信息传递。（2007）。第一部分详细介绍了重要的耦合方程及其离散化方案。为进一步验证复杂波和测深条件下二阶3D耦合模型的性能，在第二部分中，通过以下方法进行了仔细的实验​​验证：建立一个扁平的耦合盆和一个凹凸的耦合盆。另外，已经使用了一系列逐渐复杂的数值目标波，并且已经考虑了I形分段活塞式造波器系统来验证该理论。已经详细讨论了二阶3D耦合模型的有效性，适应性和精度。还从差异误差和波浪谐波分析中评估了波浪参数及其非线性对耦合模拟的影响。通过定义空间同步误差，已经分析了空间波场的整体误差。使用斜规则和不规则波，单向不规则波和多向不规则波的耦合仿真实验表明，当耦合具有强非线性的复杂波时，传统的一阶耦合模型存在局限性。当使用二阶3D耦合信号控制波时，数字波下面的高次谐波会被精确捕获并传递到物理模型中，并且不需要的二阶杂散自由波会大大减少。从本文描述的实验验证中获得的结果证明了二阶3D耦合理论的优势，随着波非线性的增加，这种优势更加明显。