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

• Applicant: Dr.-Ing. Markus Brühl
• Subject Area: Geotechnics, Hydraulic Engineering
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 323009320

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.

• DFG Programme: Research Grants
• International Connection: Netherlands