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In recent decades, the emphasis on renewable resources has grown considerably, leading to significant advances in the sector of wave energy. Nevertheless, the market cannot still be considered as commercialized, as there are still other obstacles in the mooring system for wave energy converters (WECs). The mooring system must be designed to not negatively impact the WEC’s efficiency and reduce the mooring loads. Firstly, the overview of the types of wave energy converters (WECs) are classified through operational principle, absorbing wave direction, location, and power take-off, respectively, and the power production analysis and design challenges of WECs are summarized. Then, the mooring materials, configurations, requirements, and the modeling approaches for WECs are introduced. Finally, the design of mooring systems, including the design considerations and standards, analysis models, software, current research focus, and challenges are discussed.

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This work considers the numerical modelling of wave interaction with thin porous structures, based on tests conducted in simplified conditions. Wave flume tests were conducted to measure the wave loads on thin porous sheets extending over the full water column. The porous sheets tested had a range of porosities, hole separation distances and thicknesses. Numerical and analytic models for the wave forces on the porous sheet are formulated under the assumptions of either a linear or quadratic pressure loss across the porous sheet. An iterative boundary element method (BEM) model is formulated to solve the quadratic pressure loss across the porous sheet. It is shown that the assumption of a linear pressure loss at the porous boundary is inadequate to capture the variation in the wave load with both wave frequency and amplitude, but that the quadratic model is in good agreement with the measured forces. The porosity of the sheet is shown to have the dominant effect on the wave loads. The hole separation distance affects the phase of the force on the porous wall, but has only a small effect on the amplitude of the force. The sheet thickness is shown to have a small effect on the amplitude of the force but a significant effect on the phase of the force. The results are of interest for numerical modelling of structures with thin porous boundaries in a wide range of contexts such as breakwaters, aquaculture and offshore structures with porous elements designed to reduce loads.

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