Parameterisation of nonlinear ship-induced 3D wave fields for the hydraulic design of protective structures in maritime waterways (PaNSiWa)

在过去15年中，在海上航道观察到丁坝和护岸等防护结构遭到严重破坏的情况有所增加。对这些破坏的分析表明，目前对这类结构的碎石丘层的设计方法不足以确保足够的稳定性来抵御船舶诱导的波浪荷载。由于这些方法是针对风致波浪而确定的，因此它们没有考虑长周期的船舶波浪分量。2011年，与BAW、HPA、IWW(RWTH Aachen)和LWI(TU Braunschweig)共同发起了一个联合研究项目--用于海上航道碎石堆结构设计的船舶诱导长周期荷载。该项目的重点是为碎石堆结构提供设计标准。LWI进行的分析已于2013年8月完成。结果使我们能够清楚地确定在船舶波浪分类和参数化方面的知识差距。该项目清楚地表明了对三维、非线性船舶波场进行三维分析的必要性，这不是上述联合研究项目的一部分。此外，它还提供了大量的船舶波浪数据集和宝贵的联系，这对于拟议的研究是必不可少的。拟议项目的主要目标是为海上航道抛石结构水力设计所需的船舶诱导三维波浪场的参数化提供科学知识，特别是关注船舶波浪的空间和非线性特性。主要研究内容包括：(1)非线性傅立叶变换在三维船舶尾迹场频域非线性分析中的数值实现；(2)希尔伯特-黄变换在三维船舶尾迹场非线性时频域分析中的数值实现；(3)利用已实现的分析方法(3D-NLFT和3D-HHT)与传统FFT方法对船舶波浪数据的比较分析；(4)三维船舶波浪场的参数化，以确定航道防护抛石结构物的相关水力设计参数。

In the last 15 years an increased number of serious damages of protective structures such as groins and revetments have been observed in the maritime waterways. The analyses of these damages have shown that the current design approaches for the rubble mound layers of such structures are not sufficient to ensure sufficient stability against ship-induced wave loads. Since these approaches are determined for wind-induced waves, they do not consider the long-period ship-wave components. A joint research project 'Ship-induced long-period loads for the design of rubble mound structures in maritime waterways' with BAW, HPA, IWW (RWTH Aachen) and LWI (TU Braunschweig) was initiated 2011. The focus of that project was to provide design standards for rubble mound structures. The analyses that have been conducted by LWI were completed in August 2013. The results have allowed us to clearly identify the knowledge gaps with respect to the classification and parameterization of ship waves. The project clearly has shown the need for a 3D analysis of three-dimensional, nonlinear ship wave fields, which was not part of the aforementioned joint research project. Moreover, it provided extensive ship wave data sets and valuable contacts, which are indispensable for the proposed research.The primary objective of the proposed project is to generate the scientific knowledge for the parameterization of ship-induced 3D wave fields as required for the hydraulic design of rubble mound structures in maritime waterways with a special focus on the spatial and nonlinear properties of ship waves. The key research issues are (i) the numerical implementation of a nonlinear Fourier transform for the nonlinear frequency-domain analysis of three-dimensional ship wake fields (3D-NLFT), (ii) the numerical implementation of the Hilbert-Huang transform for the nonlinear time-frequency-domain analysis of three-dimensional ship wake fields (3D-HHT), (iii) a comparative analysis of ship-wave data using the implemented analysis methods (3D-NLFT and 3D-HHT) as well as conventional FFT and (iv) the parameterization of 3D ship wave fields in order to determine the relevant hydraulic design parameters for protective rubble mound structures in maritime waterways.