Modelling Wave-Structure-Foundation Interaction for Marine Gravity Structures (WaSFI)
Final Report Abstract
The WaSFI project aims at developing a strongly coupled computational hydro-structural-geodynamic model in the OpenFOAM environment based on earlier developments of the research team. The model focuses on reproducing relevant physical processes of wave-structure-soil interaction of gravity structures in the marine environment. These processes result in the stepwise failure mechanism of marine gravity foundations, which is significantly related to soil plastic behaviour (residual liquefaction) under wave-induced cyclic loading conditions. The model was applied to selected applications in coastal and offshore engineering (e.g. marine renewable energy) including the development of an innovative breakwater concept. Through the model development and validation it was found that in contrast to horizontal wave impact loads, computational fluid dynamics models can poorly reproduce cyclic uplift pressures for all available/acceptable relations for pressure gradient due to flow in porous media (the so-called Darcy-Forchheimer models). The problem was further investigated, and it was found that for cyclic flow (typical of marine conditions) a more reliable Darcy-Forchheimer relation is needed. This relation can be developed, for example, through controlled cyclic U-tube flow through porous media experiments. The developments in the WaSFI project are the foundation of the current international research project NuLIMAS (Numerical Modelling of Liquefaction around Marine Structures) applied to by the Principle Investigator of WaSFI and coordinated by TU Braunschweig. The NuLIMAS project (funded by MaRTERA under JPI Oceans) involves partners from Germany, Poland and Turkey and aims at developing the numerical model further into a reliable virtual laboratory by extending the data for calibration and validation through new unique physical model tests and applying the numerical model to innovative offshore platforms with gravity-type anchors.
Publications
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(2016). Use of OpenFOAM® in offshore engineering for wave-structure and wave-structure-soil interactions. International Conference on Coasts, Ports And Marine Structures (ICOPMAS) Ports & Maritime Organization. Iran
Elsafti, H., Bonakdar, L., & Oumeraci, H.
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(2017). Analysis and classification of stepwise failure of monolithic breakwaters. Coastal Engineering, 121, 221-239
Elsafti, H., & Oumeraci, H.
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(2017). On Modelling Wave-Structure-Seabed Interaction. Invited lecture, 2nd International Symposium on Coastal and Offshore Geotechnics (ISCOG), 2017, Zhejiang University, Hangzhou, China, 2017
Elsafti, H.
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(2017). Optimization of the geometry and the turbine induced damping for fixed detached and asymmetric OWC devices: A numerical study. Energy, 139, 1197-1209
Simonetti, I., Cappietti, L., Elsafti, H., & Oumeraci, H.
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Analysis of stepwise failure of marine gravity structures and implications for design practice. The PIANC Yearbook, 2017
Elsafti, H.
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(2018) Modelling Turbulent Flow in Deformable Highly Porous Seabed and Structures. International Conference on Offshore Mechanics and Arctic Engineering. Vol. 51302. American Society of Mechanical Engineers, 2018
Elsafti, H., & Oumeraci., H.
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(2018). Evaluation of air compressibility effects on the performance of fixed OWC wave energy converters using CFD modelling. Renewable Energy, 119, 741-753
Simonetti, I., Cappietti, L., Elsafti, H., & Oumeraci, H.
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(2019). Hydraulic Performance of Innovative Seashell-Shaped Artificial Armor Units for Coastal Protections (SeashellBreakwater). Coastal Structures 2019
Elsafti, H., Almaghraby, M., Iskander, M., & Goseberg, N.
