In this work the numerical model DualSPHysics has been applied to study the complex phenomenon of wave overtopping characterising dike-promenade coastal defence layout. The model has been first validated, by comparing the results versus laboratory data obtained during a project campaign at the Maritime Engineering Laboratory of Universitat Politècnica de Catalunya – BarcelonaTech (LIM/UPC). The experimental campaign aimed to describe flow characteristics for the current dike and beach layout. Numerical modelling was employed to extend the experimental database beyond the range of tested conditions. In this work, a new Density Diffusion Scheme and the new modified Dynamic Boundary Conditions are applied to model wave-structure interaction. A real sea state was simulated, corresponding to a train of random waves having a duration equal to 1000 waves (= 1300s in real time). Cumulative overtopping volumes and mean discharges are calculated and compared with the experimental ones, showing a very good agreement and accuracy in not showing before in previous studies on wave overtopping with SPH-based solvers. One test case has been employed for further analysis. The model applicability and impact has been focused on reducing discharge under tolerable values by modifying the structural and beach layout. One solution corresponds to hard countermeasures to reduce overtopping discharge, employing a storm wall located on the dike crest. The other one is representative of soft countermeasures, namely beach nourishment, where the beach profile has been changed to shallower conditions to provoke more intense wave breaking and dissipate the incoming wave energy. Both alternatives guarantee tolerable discharges for coastal safety., This research was funded by European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No.: 792370., Postprint (published version)

The proposed work aims to prove the capability of the DualSPHysics numerical code to deal with the interaction of slamming waves with a Wave Energy Converter (WEC). In particular, the analysed device is a point-absorber that consists of a cylindrical heaving-buoy equipped with an air damper in order to reproduce the effect of the Power Take-Off (PTO) system. Numerical vertical displacement of the cylinder under regular waves is found to be in good agreement with experimental data for different PTO systems. Different scenarios are considered to compute the loads of focused waves acting on the device with its PTO system set on hold. The yield criterion is used to determine that keeping the WEC fixed at still water level is the worst-case scenario and submerging the heaving buoy deep enough is the best-case scenario., This work was partially financed by the Ministry of Economy and Competitiveness of the Government of Spain under project “WELCOME ENE2016-75074-C2-1-R” and financed by Xunta de Galicia (Spain) under project ED431C 2017/64 ″Programa de Con-solidación e Estructuración de Unidades de Investi-gación Competitivas (Grupos de Referencia Com-petitiva)" cofunded by European Regional Development Fund (FEDER). Fruitful discussion was held during the Course 'Mod-eling free surface flows with DualSPHysics' funded by the University of Salerno, Italy under the project N. 300393CIC19VICCIONE. Dr. C. Altomare acknowledges funding from the Eu-ropean Union’s Horizon 2020 research and innova-tion programme under the Marie Sklodowska-Curie grant agreement No.: 792370., Peer Reviewed

In this work the numerical model DualSPHysics has been applied to study the complex phenomenon of wave overtopping characterising dike-promenade coastal defence layout. The model has been first validated, by comparing the results versus laboratory data obtained during a project campaign at the Maritime Engineering Laboratory of Universitat Politècnica de Catalunya – BarcelonaTech (LIM/UPC). The experimental campaign aimed to describe flow characteristics for the current dike and beach layout. Numerical modelling was employed to extend the experimental database beyond the range of tested conditions. In this work, a new Density Diffusion Scheme and the new modified Dynamic Boundary Conditions are applied to model wave-structure interaction. A real sea state was simulated, corresponding to a train of random waves having a duration equal to 1000 waves (= 1300s in real time). Cumulative overtopping volumes and mean discharges are calculated and compared with the experimental ones, showing a very good agreement and accuracy in not showing before in previous studies on wave overtopping with SPH-based solvers. One test case has been employed for further analysis. The model applicability and impact has been focused on reducing discharge under tolerable values by modifying the structural and beach layout. One solution corresponds to hard countermeasures to reduce overtopping discharge, employing a storm wall located on the dike crest. The other one is representative of soft countermeasures, namely beach nourishment, where the beach profile has been changed to shallower conditions to provoke more intense wave breaking and dissipate the incoming wave energy. Both alternatives guarantee tolerable discharges for coastal safety., This research was funded by European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No.: 792370.

The DualSPHysics project is an open-source smoothed particle hydrodynamics (SPH) code for simulating free-surface flow. The DualSPHysics code can be run on both multi-core central processing units (CPUs) or on a graphics processing unit (GPU) and is optimised to exploit the computational power of a GPU. Since its original release in 2011, DualSPHysics has been continually developed based on latest research and hence its functionality has been expanded to include an increasing range of applications. The paper presents the basic formulation and then details of all features of SPH formulations including boundary conditions, water wave generation and absorption, coupling with other models including the discrete element method, a physics engine and mooring library, and multi-phase models. Developing an SPH code with many developers in different locations presents challenges, and ensuring rigorous validation is undertaken before code releases is an important part of the development process. The validations undertaken for the DualSPHysics code are presented followed by two example applications: an armoured breakwater with moving armour units, and a wave energy converter. Both examples demonstrate the ability of SPH to include the interconnected movement of multiple objects. Finally, the paper briefly discusses the current research challenges being addressed by the DualSPHysics consortium.

The proposed work aims to prove the capability of the DualSPHysics numerical code to deal with the interaction of slamming waves with a Wave Energy Converter (WEC). In particular, the analysed device is a point-absorber that consists of a cylindrical heaving-buoy equipped with an air damper in order to reproduce the effect of the Power Take-Off (PTO) system. Numerical vertical displacement of the cylinder under regular waves is found to be in good agreement with experimental data for different PTO systems. Different scenarios are considered to compute the loads of focused waves acting on the device with its PTO system set on hold. The yield criterion is used to determine that keeping the WEC fixed at still water level is the worst-case scenario and submerging the heaving buoy deep enough is the best-case scenario., This work was partially financed by the Ministry of Economy and Competitiveness of the Government of Spain under project “WELCOME ENE2016-75074-C2-1-R” and financed by Xunta de Galicia (Spain) under project ED431C 2017/64 ″Programa de Con-solidación e Estructuración de Unidades de Investi-gación Competitivas (Grupos de Referencia Com-petitiva)" cofunded by European Regional Development Fund (FEDER). Fruitful discussion was held during the Course 'Mod-eling free surface flows with DualSPHysics' funded by the University of Salerno, Italy under the project N. 300393CIC19VICCIONE. Dr. C. Altomare acknowledges funding from the Eu-ropean Union’s Horizon 2020 research and innova-tion programme under the Marie Sklodowska-Curie grant agreement No.: 792370., Peer Reviewed, Postprint (published version)

The DualSPHysics project is an open-source smoothed particle hydrodynamics (SPH) code for simulating free-surface flow. The DualSPHysics code can be run on both multi-core central processing units (CPUs) or on a graphics processing unit (GPU) and is optimised to exploit the computational power of a GPU. Since its original release in 2011, DualSPHysics has been continually developed based on latest research and hence its functionality has been expanded to include an increasing range of applications. The paper presents the basic formulation and then details of all features of SPH formulations including boundary conditions, water wave generation and absorption, coupling with other models including the discrete element method, a physics engine and mooring library, and multi-phase models. Developing an SPH code with many developers in different locations presents challenges, and ensuring rigorous validation is undertaken before code releases is an important part of the development process. The validations undertaken for the DualSPHysics code are presented followed by two example applications: an armoured breakwater with moving armour units, and a wave energy converter. Both examples demonstrate the ability of SPH to include the interconnected movement of multiple objects. Finally, the paper briefly discusses the current research challenges being addressed by the DualSPHysics consortium., Postprint (published version)