TY - JOUR AU - Giorgi, Giuseppe TI - Embedding parametric resonance in a 2:1 wave energy converter to get a broader bandwidth JF - RENEWABLE ENERGY J2 - RENEW ENERGY VL - 222 PY - 2024 SN - 0960-1481 DO - 10.1016/j.renene.2023.119928 UR - https://m2.mtmt.hu/api/publication/34571699 ID - 34571699 LA - English DB - MTMT ER - TY - JOUR AU - Iphineni, Haneesha AU - Winden, Bjorn AU - Girimaji, Sharath S. TI - Toward high-fidelity Numerical Wave Tank development: Scale resolving Partially-Averaged Navier-Stokes simulations of dam-break flow JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 291 PY - 2024 PG - 21 SN - 0029-8018 DO - 10.1016/j.oceaneng.2023.116407 UR - https://m2.mtmt.hu/api/publication/34649290 ID - 34649290 LA - English DB - MTMT ER - TY - JOUR AU - Bao, Xingxian AU - Li, Fumiao AU - Sun, Huihui AU - Iglesias, Gregorio AU - Shi, Hongda TI - Performance characteristics and parameter analysis of a multi-DOF wave energy converter with hybrid power take-off systems JF - ENERGY CONVERSION AND MANAGEMENT J2 - ENERG CONVERS MANAGE VL - 278 PY - 2023 PG - 17 SN - 0196-8904 DO - 10.1016/j.enconman.2023.116751 UR - https://m2.mtmt.hu/api/publication/33951036 ID - 33951036 AB - A multi-degree-of-freedom (multi-DOF) wave energy converter (WEC) with hybrid power take-off (PTO) systems may capture more wave energy than a traditional single-DOF WEC, which usually obtains energy from pitch or heave. Compared with the existing WECs with a single PTO, this paper presents the concept design of a multi-DOF WEC with hybrid PTOs named PUWEC, which has prismatic pairs in the hydraulic cylinder and univer-sal pairs in the gear transmission system. Two corresponding PTOs are matched to the motion of the buoy in heave and pitch to enhance wave energy conversion. This work focuses on establishing a time-domain numerical model to simulate the coupled dynamics and power capture performance of the proposed PUWEC. The model tests are carried out in a wave tank to verify the validity of the numerical model. The results show that the numerical model is efficient in predicting the dynamic performance of the PUWEC. Regular and irregular wave conditions are considered in the numerical simulations to explore the performance characteristics of the devices. It is found that the maximum improvement of the captured power of PUWEC is 49.8 % compared with single-DOF PWEC under the regular wave frequency 0.42 Hz, and the capture width ratio of PUWEC is close to 30 % under three wave conditions. In addition, the motion trajectory of the center of gravity of the buoy is analyzed. With the increase in U-PTO damping, the trajectory of the float changes from horizontal bowl-shaped irregular path to inclined regular hollow elliptical orbit. The trajectory coefficient is introduced to provide insights into how the PUWEC improves the energy conversion. The actual working space of the PUWEC is then calculated, which is less than the design working space, indicating that the actual performance of the PUWEC is fully developed. The proposed PUWEC and constructed numerical model which considers the coupled dynamic per-formance of dual PTOs, can provide valid reference for the design of other multi-DOF WECs with hybrid PTOs. LA - English DB - MTMT ER - TY - JOUR AU - Bechlenberg, Alva AU - Wei, Yanji AU - Jayawardhana, Bayu AU - Vakis, Antonis I. TI - Analysing the influence of power take-off adaptability on the power extraction of dense wave energy converter arrays JF - RENEWABLE ENERGY J2 - RENEW ENERGY VL - 211 PY - 2023 SP - 1 EP - 12 PG - 12 SN - 0960-1481 DO - 10.1016/j.renene.2023.04.076 UR - https://m2.mtmt.hu/api/publication/34341332 ID - 34341332 AB - The aim of this work is to assess the influence of different degrees of adaptability of the power take-off (PTO) system on the power absorption of dense wave energy converter (WEC) arrays. The adaptability is included in simulations through a transmission ratio that scales the force actuating the PTO relative to the force generated by the motion of a floater. A numerical model is used in which hydrodynamic interactions between floaters and nonlinearities in the PTO are considered. The lower computational cost of this numerical model makes it possible to study the power extraction of a dense WEC array in irregular waves to easily create power matrices and other performance metrics. The methodology is applied to the case study of the Ocean Grazer WEC to showcase the potential performance improvements achieved through the inclusion of a transmission ratio. The analysis shows that including a high degree of adaptability and choosing WEC array configurations and PTO designs specific to potential deployment locations early in the design process can lead to an increase in extracted power. LA - English DB - MTMT ER - TY - JOUR AU - da Silva, L. S. P. AU - Pesce, C. P. AU - de Oliveira, M. AU - Sergiienko, N. Y. AU - Cazzolato, B. AU - Ding, B. TI - Stochastic analysis of the nonlinear dynamics of oscillating water columns: A domain JF - APPLIED OCEAN RESEARCH J2 - APPL OCEAN RES VL - 139 PY - 2023 PG - 10 SN - 0141-1187 DO - 10.1016/j.apor.2023.103711 UR - https://m2.mtmt.hu/api/publication/34341330 ID - 34341330 AB - This paper investigates the first and second-order stochastic responses of oscillating water columns (OWCs) under random waves. The OWCs' nonlinear dynamics are computed in the frequency domain, where sources of nonlinearities are replaced by equivalent polynomial terms up to second order by minimising their difference in a mean-square sense. This procedure is known as the statistical quadratisation (SQ) technique. In such an approach, the linear and quadratic coefficients are obtained using an iterative procedure and non-Gaussian distributions based on Gram-Charlier expansions, and the dynamics are solved using the Volterra theory. The results are compared against a statistical linearisation model (SL), and nonlinear time-domain simulations (TD) to illustrate the capabilities of the method. The result demonstrated an excellent agreement for the first and second-order motions of the water column obtained using statistical quadratisation compared to nonlinear time domain simulations in terms of spectral response and probability distribution. Along with the good accuracy, the statistical quadratisation has the advantage of being approximately two orders of magnitude faster than nonlinear time-domain simulations. For the proposed systems, the nonlinearity from the variable mass system (inertial type) is shown to be the most important source of second-order effects driving the oscillating water column dynamics based on the environmental conditions and drafts investigated in this work. LA - English DB - MTMT ER - TY - JOUR AU - Faedo, Nicolas AU - Pena-Sanchez, Yerai AU - Pasta, Edoardo AU - Papini, Guglielmo AU - Mosquera, Facundo D. AU - Ferri, Francesco TI - SWELL: An open-access experimental dataset for arrays of wave energy conversion systems JF - RENEWABLE ENERGY J2 - RENEW ENERGY VL - 212 PY - 2023 SP - 699 EP - 716 PG - 18 SN - 0960-1481 DO - 10.1016/j.renene.2023.05.069 UR - https://m2.mtmt.hu/api/publication/34321749 ID - 34321749 AB - Achieving large-scale commercial exploitation of ocean wave energy inherently encompasses the design and deployment of arrays of wave energy converters (WECs), in an effort to reduce the associated levelised cost of energy. In this context, understanding the interactions between devices in a controlled WEC array is hence essential to achieve optimal layout configurations, as well as to provide guidance on the area required for array installation, reliability, life-time, and overall cost of the farm. Successful achievement of these vital objectives for the wave energy industry has been constantly aided by the use of appropriate numerical models. Regardless of the specific modelling approach adopted, model reliability is always a major concern: Numerical models need to able be to represent reality to be useful in supporting the different stages of development, hence providing significant results for decision making. To test reliability of a model, experimental results are an invaluable asset for validation.Recognising the striking absence of real-world data concerning arrays of WEC systems, and its inherent value for model validation and data-based modelling purposes, we present, in this paper, an experimental campaign fully conducted with the sole objective of generating and providing an open-access dataset on WEC farms: SWELL (Standardised Wave Energy converter array Learning Library). The generated dataset, included alongside this manuscript, comprises an approximate total of similar to 3000 variables and more than similar to 108 datapoints, for up to 5 devices in 9 diverse WEC array layouts with different levels of interaction, and 19 carefully selected operating conditions. Four different categories of tests are considered, providing measures of key variables required for model validation and data-based modelling tasks. As such, SWELL provides a crucial resource to achieve confidence in numerical modelling, helping towards creating reliable tools for decision making in the WEC field, hence effectively supporting the pathway towards effective commercialisation of ocean wave energy. LA - English DB - MTMT ER - TY - JOUR AU - Khojasteh, Danial AU - Shamsipour, Abbas AU - Huang, Luofeng AU - Tavakoli, Sasan AU - Haghani, Milad AU - Flocard, Francois AU - Farzadkhoo, Maryam AU - Iglesias, Gregorio AU - Hemer, Mark AU - Lewis, Matthew AU - Neill, Simon AU - Bernitsas, Michael M. AU - Glamore, William TI - A large-scale review of wave and tidal energy research over the last 20 years JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 282 PY - 2023 PG - 18 SN - 0029-8018 DO - 10.1016/j.oceaneng.2023.114995 UR - https://m2.mtmt.hu/api/publication/34341331 ID - 34341331 AB - Over the last two decades, a large body of academic scholarship has been generated on wave and tidal energy related topics. It is therefore important to assess and analyse the research direction and development through horizon scanning processes. To synthesise such large-scale literature, this review adopts a bibliometric method and scrutinises over 8000 wave/tidal energy related documents published during 2003-2021. Overall, 98 countries contributed to the literature, with the top ten mainly developed countries plus China produced nearly two-thirds of the research. A thorough analysis on documents marked the emergence of four broad research themes (dominated by wave energy subjects): (A) resource assessment, site selection, and environmental impacts/benefits; (B) wave energy converters, hybrid systems, and hydrodynamic performance; (C) vibration energy harvesting and piezoelectric nanogenerators; and (D) flow dynamics, tidal turbines, and turbine design. Further, nineteen research sub-clusters, corresponding to broader themes, were identified, highlighting the trending research topics. An interesting observation was a recent shift in research focus from solely evaluating energy resources and ideal sites to integrating wave/tidal energy schemes into wider coastal/estuarine management plans by developing multicriteria decision-making frameworks and promoting novel designs and costsharing practices. The method and results presented may provide insights into the evolution of wave/tidal energy science and its multiple research topics, thus helping to inform future management decisions. LA - English DB - MTMT ER - TY - JOUR AU - Olbert, Gerrit AU - Abdel-Maksoud, Moustafa TI - High-fidelity modelling of lift-based wave energy converters in a numerical wave tank JF - APPLIED ENERGY J2 - APPL ENERG VL - 347 PY - 2023 PG - 19 SN - 0306-2619 DO - 10.1016/j.apenergy.2023.121460 UR - https://m2.mtmt.hu/api/publication/34331824 ID - 34331824 AB - This work presents the development of a numerical model for the investigation of lift-based wave energy converter (lift-WEC) hydrodynamics. The developed model, based on the RANS equation, is validated regarding its ability to replicate foil-flow interaction in various conditions based on experimental references from literature. Limitations of the numerical model are discussed, such as the overprediction of stall angles at low Reynolds numbers and the possibility of artificial rotor ventilation near the free surface. Within the range of relevant operating conditions for a lift-WEC, the model is found to replicate experimental results with good accuracy. Subsequently, a particularity of the cyclorotor WEC concept is investigated: Load measurements in calm water showed positive tangential forces, apparently indicating the generation of thrust in the absence of external energy sources. Numerical simulations reveal that this is the result of a significant azimuthal shift of the hydrodynamic load centre for non-zero pitch and that the consideration of foil pitch moments is required in order to obtain accurate shaft torque predictions. The hydrodynamic coefficients of the cyclorotor foils are compared with coefficients obtained for symmetrical foils in straight flight. It is shown that the assumption of similarity, which is often applied when modelling these devices in semi-analytical tools, is only valid for small angles of attack. LA - English DB - MTMT ER - TY - JOUR AU - Opoku, F AU - Uddin, MN AU - Atkinson, M TI - A review of computational methods for studying oscillating water columns–the Navier-Stokes based equation approach JF - RENEWABLE & SUSTAINABLE ENERGY REVIEWS J2 - RENEW SUST ENERG REV VL - 174 PY - 2023 SP - 113124 SN - 1364-0321 DO - 10.1016/j.rser.2022.113124 UR - https://m2.mtmt.hu/api/publication/33600379 ID - 33600379 LA - English DB - MTMT ER - TY - JOUR AU - Ringwood, John V AU - Zhan, Siyuan AU - Faedo, Nicolas TI - Empowering wave energy with control technology: Possibilities and pitfalls JF - ANNUAL REVIEWS IN CONTROL J2 - ANNU REV CONTROL VL - 55 PY - 2023 SP - 18 EP - 44 PG - 27 SN - 1367-5788 DO - 10.1016/j.arcontrol.2023.04.004 UR - https://m2.mtmt.hu/api/publication/34321709 ID - 34321709 AB - With an increasing focus on climate action and energy security, an appropriate mix of renewable energy technologies is imperative. Despite having considerable global potential, wave energy has still not reached a state of maturity or economic competitiveness to have made an impact. Challenges include the high capital and operational costs associated with deployment in the harsh ocean environment, so it is imperative that the full energy harnessing capacity of wave energy devices, and arrays of devices in farms, is realised. To this end, control technology has an important role to play in maximising power capture, while ensuring that physical system constraints are respected, and control actions do not adversely affect device lifetime. Within the gamut of control technology, a variety of tools can be brought to bear on the wave energy control problem, including various control strategies (optimal, robust, nonlinear, etc.), data-based model identification, estimation, and forecasting. However, the wave energy problem displays a number of unique features which challenge the traditional application of these techniques, while also presenting a number of control 'paradoxes'. This review articulates the important control-related characteristics of the wave energy control problem, provides a survey of currently applied control and control-related techniques, and gives some perspectives on the outstanding challenges and future possibilities. The emerging area of control co-design, which is especially relevant to the relatively immature area of wave energy system design, is also covered. LA - English DB - MTMT ER - TY - JOUR AU - Tagliafierro, Bonaventura AU - Karimirad, Madjid AU - Altomare, Corrado AU - Goeteman, Malin AU - Martinez-Estevez, Ivan AU - Capasso, Salvatore AU - Dominguez, Jose M. AU - Viccione, Giacomo AU - Gomez-Gesteira, Moncho AU - Crespo, Alejandro J. C. TI - Numerical validations and investigation of a semi-submersible floating offshore wind turbine platform interacting with ocean waves using an SPH framework JF - APPLIED OCEAN RESEARCH J2 - APPL OCEAN RES VL - 141 PY - 2023 PG - 26 SN - 0141-1187 DO - 10.1016/j.apor.2023.103757 UR - https://m2.mtmt.hu/api/publication/34341329 ID - 34341329 AB - In this work, we propose numerical validations of the DeepCwind semi-submersible floating platform config-uration for a single horizontal axis wind turbine using data from two experimental testing investigations. A Smoothed Particle Hydrodynamics solver is employed to estimate fluid induced loads, whereas the mooring connections are handled via an external library. The first validation setup is based on the DeepCwind offshore wind semi-submersible concept moored with a system of taut-lines and tested for free-decay surge and heave motion (OC6-Phase Ia). The damping evaluation yields a fair estimation of the heave damping behavior, whereas much more dissipation is experienced for the surge. The second validation features a full hydrodynamic characterization of the frequency-related load patterns induced by three different sea-state representations (mono-, bi-chromatic, and irregular waves) (OC6-Phase Ib). The model accurately matches the hydrodynamic load estimation for the whole spectrum of investigated wave components, perfectly capturing the non-linear behavior shown by the considered wave patterns. This work concludes with a systematic study on the motion response, mooring tension, pressure and vorticity, suggesting that: the wave steepness criterion alone cannot identify the most restrictive load case; waves with spectral characteristics close to the heave resonance period lead to higher tensions in the mooring systems, whereas the maximum fluid-induced loads on the hull are decoupled from displacement peaks, showing an average reduction of 30% with respect to the maxima; very steep waves maximize the likelihood of wave overtopping and slamming loads, resulting in locally induced overpressure on the free-board of up to 100% higher than expected for similar wave heights with milder profiles. The input data for these last tests is released for the sake of reproduction. LA - English DB - MTMT ER - TY - JOUR AU - Tavakoli, Sasan AU - Khojasteh, Danial AU - Haghani, Milad AU - Hirdaris, Spyros TI - A review on the progress and research directions of ocean engineering JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 272 PY - 2023 PG - 36 SN - 0029-8018 DO - 10.1016/j.oceaneng.2023.113617 UR - https://m2.mtmt.hu/api/publication/33890021 ID - 33890021 AB - This paper reviews research in ocean engineering over the last 50+ years with the aim to (I) understand the technological challenges and evolution in the field, (II) investigate whether ocean engineering studies meet present global demands, (III) explore new scientific/engineering tools that may suggest pragmatic solutions to problems, and (IV) identify research and management gaps, and the way forward. Six major research divisions are identified, namely (I) Ocean Hydrodynamics, (II) Risk Assessment and Safety, (III) Ocean Climate and Geophysics: Data and Models, (IV) Control and Automation in the Ocean, (V) Structural Engineering and Manufacturing for the Ocean, and (VI) Ocean Renewable Energy. As much as practically possible research sub-divisions of the field are also identified. It is highlighted that research topics dealing with ocean renewable energy, control and path tracking of ships, as well as computational modelling of wave-induced motions are growing. Updating and forecasting energy resources, developing computational methods for wave generation, and introducing novel methods for the optimised control of energy converters are highlighted as the potential research opportunities. Ongoing studies follow the global needs for environmentally friendly renewable energies, though engineering-based studies often tend to overlook the longer-term potential influence of climate change. Development and exploitation of computational engineering methods with focus on continuum mechanics problems remain relevant. Notwithstanding this, machine learning methods are attracting the attention of re-searchers. Analysis of COVID-19 transmission onboard is rarely conducted, and 3D printing-based studies still need more attention from researchers. LA - English DB - MTMT ER - TY - JOUR AU - Choupin, Ophelie AU - Henriksen, Michael AU - Tomlinson, Rodger TI - Interrelationship between variables for wave direction-dependent WEC/site-configuration pairs using the CapEx method JF - ENERGY J2 - ENERGY VL - 248 PY - 2022 PG - 22 SN - 0360-5442 DO - 10.1016/j.energy.2022.123552 UR - https://m2.mtmt.hu/api/publication/33451430 ID - 33451430 AB - Renewable energies are mostly compared using the Levelised Cost of Energy (LCoE). Two major components of LCoE are of interest in this study, the others being still experimental: the Annual Energy Production (AEP) and the Capital Expenditure (CapEx). Since many Wave Energy Converters (WECs), including Wavepiston, are wave direction-dependent, this research investigates the wave direction impact on the relationship between the site-configurations (site characteristics and wave climates), WEC-configurations and power, alongside AEP and CapEx. Wave climate and WEC power are expressed in 3-dimension by adding the wave direction to the common 2-dimensional space of wave height and period. Wavepiston's WEF costs are calculated using the CapEx method. Assessing the relationship between the diverse sources of AEP/CapEx variations, enabled the development of the Cost-AEP Threshold Criterion (CAEPTC) to determine the threshold where an increase in AEP becomes negligible compared to CapEx increase. CAEPTC is perhaps a better alternative to LCoE for enhanced WEC/site-configuration pairing. Based on this Criterion and the limited dataset (a challenge to most wave companies), it was apparent that the best WEC/site-configuration pairs came from configurations with the highest yearly energy production, which is not necessarily the most expensive, and for sites with lower wave energy. (c) 2022 Elsevier Ltd. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - da Silva, L. S. P. AU - Sergiienko, N. Y. AU - Cazzolato, B. AU - Ding, B. TI - Dynamics of hybrid offshore renewable energy platforms: Heaving point absorbers connected to a semi-submersible floating offshore wind turbine JF - RENEWABLE ENERGY J2 - RENEW ENERGY VL - 199 PY - 2022 SP - 1424 EP - 1439 PG - 16 SN - 0960-1481 DO - 10.1016/j.renene.2022.09.014 UR - https://m2.mtmt.hu/api/publication/33477963 ID - 33477963 AB - Hybrid platforms composed of a floating offshore wind turbine (FOWT) and wave energy converters (WECs) may possibly reduce the levelised cost of energy of both energy harvesting devices and improve the platform dynamics. This paper investigates the dynamics of a hybrid platform composed of a semi-submersible FOWT combined with three spherical heaving point absorbers (PAs), either floating or submerged, under turbulent wind and irregular waves conditions. Since the WECs are attached to the floating structure, complex hydrodynamic couplings occur between the floating bodies. In this regard, a parametric investigation of the power-take-off system is performed to understand the wave power absorption and motion characteristics, which are compared against their respective stand-alone configurations. At sea states with short wave peak period, both hybrid platforms (with floating or submerged PAs) were able to operate under maximum wave power absorption condition and extract nearly the same amount of wave energy as the PAs attached to the ground (stand-alone), while providing the additional benefit of reducing the horizontal nacelle accelerations of the FOWT. On the other hand, when operating at sea states with long wave periods, the hybrid platforms may need to restrict the wave power absorption capability to prevent additional nacelle horizontal acceleration. LA - English DB - MTMT ER - TY - JOUR AU - Da Silva, L. S. P. AU - De Oliveira, M. AU - Cazzolato, B. AU - Sergiienko, N. AU - Amaral, G. A. AU - Ding, B. TI - Statistical linearisation of a nonlinear floating offshore wind turbine under random waves and winds JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 261 PY - 2022 PG - 15 SN - 0029-8018 DO - 10.1016/j.oceaneng.2022.112033 UR - https://m2.mtmt.hu/api/publication/33477964 ID - 33477964 AB - This paper investigates the stochastic nonlinear dynamics of a floating offshore wind turbine (FOWT) in the frequency-domain under irregular waves and turbulent winds. The main sources of nonlinearities are estimated using statistical linearisation, which are calculated based on probability density functions (PDFs) between the degrees-of-freedom and the environment. The nonlinear mooring model captures the coupling between degrees -of-freedom when the platform has a mean displacement caused by the wind thrust, changing the natural frequency especially in surge. In addition, the nonlinear viscous drag loads offer an hydrodynamic damping that lead to better estimates of the responses. The nonlinear aerodynamic loads uses the relative motion experienced by the wind turbine under turbulent wind, and the concept of aerodynamic admittance function, which has not been applied yet to FOWTs, is included to capture the spatial effects of the wind turbulence. The results are benchmarked against nonlinear time-domain simulations using OpenFAST, and good agreement is obtained in terms of power spectral densities, PDFs and standard deviations. Several environmental conditions are used to explore some of the platform characteristics and salient features from the model. The main advantage of the following approach is the low computational cost, while providing reliable estimates of the response. LA - English DB - MTMT ER - TY - JOUR AU - Davidson, Joshua Patrick AU - Kalmár-Nagy, Tamás AU - Habib, Giuseppe TI - Parametric excitation suppression in a floating cylinder via dynamic vibration absorbers: a comparative analysis JF - NONLINEAR DYNAMICS J2 - NONLINEAR DYNAM VL - 110 PY - 2022 SP - 1081 EP - 1108 PG - 28 SN - 0924-090X DO - 10.1007/s11071-022-07710-1 UR - https://m2.mtmt.hu/api/publication/33039229 ID - 33039229 N1 - Department of Fluid Mechanics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Budapest, Hungary Department of Applied Mechanics, Faculty of Mechanical Engineering, MTA-BME Lendület “Momentum” Global Dynamics Research Group Budapest University of Technology and Economics, Budapest, Hungary Correspondence Address: Davidson, J.; Department of Fluid Mechanics, Hungary; email: davidson@ara.bme.hu AB - Parametric excitation in the pitch/roll degrees of freedom (DoFs) can induce dynamic instability in floating cylinder-type structures such as spar buoys, floating offshore wind or wave energy converters. At certain frequency and amplitude ranges of the input waves, parametric coupling between the heave and pitch/roll DoFs results in undesirable large amplitude rotational motion. One possible remedy to mitigate the existence of parametric resonance is the use of dynamic vibration absorbers. Two prominent types of dynamic vibration absorbers are tuned mass dampers (TMDs) and nonlinear energy sinks (NESs), which have contrasting properties with regard to their amplitude and frequency dependencies when absorbing kinetic energy from oscillating bodies. This paper investigates the suppression of parametric resonance in floating bodies utilizing dynamic vibration absorbers, comparing the performance of TMDs against NESs for a test case considering a floating vertical cylinder. In addition to the type of dynamic vibration absorber utilized, the paper also examines the DoF which it acts on, comparing the benefits between attaching the vibration absorber to the primary (heave) DoF or the secondary (pitch) DoF. The results show that the TMD outperforms the NES and that it is more effective to attach the vibration absorber to the heave DoF when eliminating parametric resonance in the pitch DoF. LA - English DB - MTMT ER - TY - JOUR AU - Giannini, Gianmaria AU - Rosa-Santos, Paulo AU - Ramos, Victor AU - Taveira-Pinto, Francisco TI - Wave energy converters design combining hydrodynamic performance and structural assessment JF - ENERGY J2 - ENERGY VL - 249 PY - 2022 PG - 14 SN - 0360-5442 DO - 10.1016/j.energy.2022.123641 UR - https://m2.mtmt.hu/api/publication/33477973 ID - 33477973 AB - The design of a wave energy converter (WEC) is a many-sided and important assignment that determines its future technical and economic viability. Presently, there is a lack of structured design methodologies that take into account both the hydrodynamic performance, structural reliability and economic data from early development stages. Therefore, a new methodology is proposed, aiming for a viable predesign solution for avoiding major setbacks at later stages. It includes a series of steps related to the initial design definition, hydrodynamic analysis, yield strength investigation and early-stage economic assessment. For demonstration, the methodology is applied to progress a sloped motion WEC for nearshore locations. The original WEC configuration is also assessed and the novel design, which allows reducing the mass of floating elements by 70%, is developed. It is found that: for recurrent sea states, the capture width ratio of the new design (20-40%) is similar to the one of the original design (20-50%), the estimated cost of the device is reduced by 28.6% and the payback period is reduced by 2.4 years. Overall, the results obtained for the case study demonstrated the interest in the proposed methodology that can assist in the development and analysis of early-stage WEC concepts. (c) 2022 Elsevier Ltd. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Golbaz, Danial AU - Asadi, Rojin AU - Amini, Erfan AU - Mehdipour, Hossein AU - Nasiri, Mahdieh AU - Etaati, Bahareh AU - Naeeni, Seyed Taghi Omid AU - Neshat, Mehdi AU - Mirjalili, Seyedali AU - Gandomi , Amirhossein TI - Layout and design optimization of ocean wave energy converters: A scoping review of state-of-the-art canonical, hybrid, cooperative, and combinatorial optimization methods JF - ENERGY REPORTS J2 - ENERGY REP VL - 8 PY - 2022 SP - 15446 EP - 15479 PG - 34 SN - 2352-4847 DO - 10.1016/j.egyr.2022.10.403 UR - https://m2.mtmt.hu/api/publication/33331485 ID - 33331485 LA - English DB - MTMT ER - TY - JOUR AU - Khedkar, Kaustubh AU - Bhalla, Amneet Pal Singh TI - A model predictive control (MPC)-integrated multiphase immersed boundary (IB) framework for simulating wave energy converters (WECs) JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 260 PY - 2022 PG - 25 SN - 0029-8018 DO - 10.1016/j.oceaneng.2022.111908 UR - https://m2.mtmt.hu/api/publication/33399762 ID - 33399762 AB - In this work, we present a novel MPC-integrated multiphase IB framework that can compute the optimal energy-maximizing control force "on-the-fly"by dynamically interacting with a high-fidelity numerical wave tank (NWT). The computational model closely mimics the working setup of the device at its site of operation. Due to the requirement of solving a constrained optimization problem at each time step of the IB simulation, the MPC algorithm utilizes a low-dimensional dynamical model of the device that is based on the linear potential theory (LPT). The multiphase IB solver, on the other hand, is based on the high-dimensional fictitious domain Brinkman penalization (FD/BP) method, which fully-resolves the hydrodynamic non-linearities associated with the wave-structure interaction (WSI). A time-series forecasting auto-regressive model is implemented that predicts wave heights (from the past NWT data) to estimate the future wave excitation/Froude-Krylov forces for the MPC algorithm. Moreover, we also experiment with non-linear Froude-Krylov (NLFK) forces for the first time in an MPC formulation. The NLFK forces are computed efficiently using a static Cartesian grid, in which the WEC geometry is implicitly represented by a signed distance function. Under varying sea conditions, the predictions of the MPC-integrated multiphase IB solver are compared to the widely popular LPT-based solvers. In agitated sea conditions and/or under aggressive control, the LPT-based WSI solvers produce too optimistic (and misleading) power output values. Overall, six WSI/MPC solver combinations are compared for a heaving vertical cylinder to determine the reasons for discrepancies between high-and low-fidelity predictions. We also determine the pathway of energy transfer from the waves to the power take-off (PTO) system and verify the relationships using IB simulations. Additionally, three different sea states are simulated within the IB simulation to test the adaptive capability of MPC for WECs. MPC is demonstrated to adapt to changing sea conditions and find the optimal solution for each sea state.The interaction between the distributed-memory parallel multiphase IB solver (written in C++) and the serial MPC solver (written in MATLAB) is fully described to facilitate reproducibility. A bespoke communication layer between the two solvers is developed, which can be easily modified by the WEC community to experiment with other optimal controllers and computational fluid dynamics (CFD) solvers. All codes for this work are made open-source for pedagogical and research purposes. LA - English DB - MTMT ER - TY - JOUR AU - Lama, Giuseppe Francesco Cesare AU - Sadeghifar, Tayeb AU - Azad, Masoud Torabi AU - Sihag, Parveen AU - Kisi, Ozgur TI - On the Indirect Estimation of Wind Wave Heights over the Southern Coasts of Caspian Sea: A Comparative Analysis JF - WATER J2 - WATER-SUI VL - 14 PY - 2022 IS - 6 PG - 13 SN - 2073-4441 DO - 10.3390/w14060843 UR - https://m2.mtmt.hu/api/publication/33477976 ID - 33477976 AB - The prediction of ocean waves is a highly challenging task in coastal and water engineering in general due to their very high randomness. In the present case study, an analysis of wind, sea flow features, and wave height in the southern coasts of the Caspian Sea, especially in the off-coast sea waters of Mazandaran Province in Northern Iran, was performed. Satellite altimetry-based significant wave heights associated with the period of observation in 2016 were validated based on those measured at a buoy station in the same year. The comparative analysis between them showed that satellite-based wave heights are highly correlated to buoy data, as testified by a high coefficient of correlation r (0.87), low Bias (0.063 m), and root-mean-squared error (0.071 m). It was possible to assess that the dominant wave direction in the study area was northwest. Considering the main factors affecting wind-induced waves, the atmospheric framework in the examined sea region with high pressure was identified as the main factor to be taken into account in the formation of waves. The outcomes of the present research provide an interesting methodological tool for obtaining and processing accurate wave height estimations in such an intricate flow playground as the southern coasts of the Caspian Sea. LA - English DB - MTMT ER - TY - JOUR AU - Li, Xiang AU - Xiao, Qing AU - Zhou, Yang AU - Ning, Dezhi AU - Incecik, Atilla AU - Nicoll, Ryan AU - McDonald, Anthony AU - Campbell, David TI - Coupled CFD-MBD numerical modeling of a mechanically coupled WEC array JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 256 PY - 2022 PG - 15 SN - 0029-8018 DO - 10.1016/j.oceaneng.2022.111541 UR - https://m2.mtmt.hu/api/publication/33477969 ID - 33477969 AB - The development of new wave energy devices (WECs) has continued unabated over the past decades. For largescale applications, integrating individual WEC into an array system (WEC net) requires considerable expertise and research due to its highly complex and interrelated nature. Often for a WEC net, it contains main structures and multiple sub-structures. The WEC net response is defined as the total responses from all sub-structures, which is highly complex and closely interconnected with each other. This paper aims to develop a fully-coupled numerical modeling tool that can cope with the wave-structure interaction as well as the mechanical interaction among each sub-structure in a WEC net. The fluid field is solved by a Computational Fluid Dynamic (CFD) solver coupled with a Multi-body Dynamic structural solver. The hydrodynamic and power take-off performance of Albatern 12S Squid WEC net is studied and the results are validated against available laboratory testing data, and commercial mooring and hydrodynamics analysis software.It is found that the motion response of the CFD and experimental approach is in close agreement with each other. The interaction force among sub-structures can be well captured, and the results indicate that the mode response of individual float is strongly affected by the mechanical linking-arms as well as the incident wave conditions, which is hard to achieve without such integrated CFD tool. The power take-off (PTO) is modeled using a damping system. The predicted peak output power is found to increase with the decreasing of wave period and an optimal device's damping to reach a maximum power capture exists, which is dependent on the incoming wave period and height. LA - English DB - MTMT ER - TY - JOUR AU - Robaux, Fabien AU - Benoit, Michel TI - Assessment of one-way coupling methods from a potential to a viscous flow solver based on domain- and functional-decomposition for fixed submerged bodies in nonlinear waves JF - EUROPEAN JOURNAL OF MECHANICS B-FLUIDS J2 - EUR J MECH B-FLUID VL - 95 PY - 2022 SP - 315 EP - 334 PG - 20 SN - 0997-7546 DO - 10.1016/j.euromechflu.2022.05.011 UR - https://m2.mtmt.hu/api/publication/33477967 ID - 33477967 AB - To simulate the interaction of ocean waves with marine structures, coupling approaches between a potential flow model and a viscous model are investigated. The first model is a fully nonlinear potential flow (FNPF) model based on the Harmonic Polynomial Cell (HPC) method, which is highly accurate and best suited for representing long distance wave propagation. The second model is a CFD code, solving the Reynolds-Averaged Navier-Stokes (RANS) equations within the OpenFOAM (R) toolkit, more suited to represent viscous and turbulent effects at local scale in the body vicinity. Two one-way coupling strategies are developed and compared in two dimensions, considering fully submerged and fixed structures. A domain decomposition (DD) strategy is first considered, introducing a refined mesh in the body vicinity on which the RANS equations are solved. Boundary conditions and interpolation operators from the FNPF results are developed in order to enforce values at its outer boundary. The second coupling strategy considers a decomposition of variables (functional decomposition, FD) on the local grid. As the FNPF simulation provides fields of variables satisfying the irrotational Euler equations, complementary velocity and pressure components are introduced as the difference between the total flow variables and the potential ones. Those complementary variables are solutions of modified RANS equations. Extensive comparisons are presented for nonlinear waves interacting with a horizontal cylinder of rectangular cross-section. The loads exerted on the body computed from the four simulation methods (standalone FNPF, standalone CFD, DD and FD coupling schemes) are compared with experimental data. It is shown that both coupling approaches produce an accurate representation of the loads and associated hydrodynamic coefficients (inertia and drag) over a large range of incident wave steepness and Keulegan-Carpenter number, for a small fraction of the computational time needed by the complete CFD simulation. (C) 2022 Elsevier Masson SAS. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Schubert, Benjamin W. AU - Robertson, William S. P. AU - Cazzolato, Benjamin S. AU - Sergiienko, Nataliia Y. AU - Ghayesh, Mergen H. TI - Nonlinear stiffness enhancement of submerged wave energy device in high fidelity model JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 254 PY - 2022 PG - 18 SN - 0029-8018 DO - 10.1016/j.oceaneng.2022.111295 UR - https://m2.mtmt.hu/api/publication/33477971 ID - 33477971 AB - A three degree of freedom submerged wave energy converter with a nonlinear stiffness mechanism was modelled using both linear and nonlinear hydrodynamics. The linear hydrodynamics scenario used linear potential flow methods to predict the fluid-structure interaction, while the nonlinear hydrodynamic scenario use computational fluid dynamics (OpenFOAM). The potential energy of the nonlinear stiffness mechanism was varied relative to the potential energy of the incident wave. The wave energy converter was excited using regular and irregular waves. The nonlinear stiffness scenarios were compared to scenarios with optimised linear control parameters. When compared to optimal conditions, models using linear hydrodynamics to emulate both regular and irregular waves showed no improvement in power generation. In the regular wave nonlinear hydrodynamic scenarios, the nonlinear stiffness showed inconsistent improvements to power production and significant detuning at different levels of nonlinearity. The irregular wave scenario using nonlinear hydrodynamic methods demonstrated a small improvement compared to optimised linear control parameters when the nonlinear stiffness potential energy peak was less than half the potential energy of the incident wave. The nonlinear stiffness improved the robustness of the wave energy converter, and was an effective method for detuning the system, depending on the degree of nonlinearity. LA - English DB - MTMT ER - TY - JOUR AU - Tagliafierro, Bonaventura AU - Martinez-Estevez, Ivan AU - Dominguez, Jose M. AU - Crespo, Alejandro J. C. AU - Goteman, Malin AU - Engstrom, Jens AU - Gomez-Gesteira, Moncho TI - A numerical study of a taut-moored point-absorber wave energy converter with a linear power take-off system under extreme wave conditions JF - APPLIED ENERGY J2 - APPL ENERG VL - 311 PY - 2022 PG - 19 SN - 0306-2619 DO - 10.1016/j.apenergy.2022.118629 UR - https://m2.mtmt.hu/api/publication/33399772 ID - 33399772 AB - Probably the biggest challenge for wave energy is to ensure survival in harsh offshore conditions, in order to reduce costs for offshore repair operations and downtime, and achieve economic viability. This work presents a reliable numerical tool that can be used to study the dynamics and survivability of wave energy converters in violent wave conditions, possibly cutting down the costs of experimental campaigns. Within the Smoothed Particle Hydrodynamics framework, this research identifies a detailed procedure to model a taut-moored point absorber wave energy converter together with its inherent power take-off device, which seamlessly exploits its functions of energy harvesting and load bearing. A validation of the DualSPHysics code is provided by contrasting the numerical outcome with a thorough set of data obtained in physical tests with extreme waves, showing that the time-integrated numerical model can capture with good accuracy all the physics involved. The computational fluid dynamics tool is employed to perform a survivability study, modeling high-return period wave conditions for marine structures, and providing guidelines on how to create the numerically best setup to be used for design purposes. A real-like irregular sea state representation, comprising 500 waves, was used to draw insightful indications for the structure optimization to increase the structure's life expectancy, or conversely, to reduce the initial and operational costs. LA - English DB - MTMT ER - TY - JOUR AU - Visbech, Jens AU - Engsig-Karup, Allan P. AU - Bingham, Harry B. TI - A spectral element solution of the two-dimensional linearized potential flow radiation problem JF - INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS J2 - INT J NUMER METH FL PY - 2022 PG - 19 SN - 0271-2091 DO - 10.1002/fld.5157 UR - https://m2.mtmt.hu/api/publication/33477961 ID - 33477961 AB - We present a scalable two-dimensional Galerkin spectral element method solution to the linearized potential flow radiation problem for wave induced forcing of a floating offshore structure. The pseudo-impulsive formulation of the problem is solved in the time domain using a Gaussian displacement signal tailored to the discrete resolution. The added mass and damping coefficients are then obtained via Fourier transformation. The spectral element method is used to discretize the spatial fluid domain, whereas the classical explicit 4-stage fourth-order Runge-Kutta scheme is employed for the temporal integration. Spectral convergence of the proposed model is established for both affine and curvilinear elements, and the computational effort is shown to scale with O(N-p), with N being the total number of grid points and p approximate to 1.12. The solver is used to compute the hydrodynamic coefficients for several floating bodies and compared against known public benchmark results. The results show excellent agreement, ultimately validating the solver and emphasizing the geometrical flexibility and high accuracy and efficiency of the proposed solution strategy. Lastly, an extensive investigation of nonresolved energy from the pseudo-impulse is carried out to characterize the induced spurious oscillations of the free surface quantities leading to a robust strategy for tuning the pseudo-impulsivemotion to the spatial discretization. LA - English DB - MTMT ER - TY - JOUR AU - Bingham, Harry B. AU - Yu, Yi-Hsiang AU - Nielsen, Kim AU - Tran, Thanh Toan AU - Kim, Kyong-Hwan AU - Park, Sewan AU - Hong, Keyyong AU - Said, Hafiz Ahsan AU - Kelly, Thomas AU - Ringwood, John V. AU - Read, Robert W. AU - Ransley, Edward AU - Brown, Scott AU - Greaves, Deborah TI - Ocean Energy Systems Wave Energy Modeling Task 10.4: Numerical Modeling of a Fixed Oscillating Water Column JF - ENERGIES J2 - ENERGIES VL - 14 PY - 2021 IS - 6 PG - 35 SN - 1996-1073 DO - 10.3390/en14061718 UR - https://m2.mtmt.hu/api/publication/32408836 ID - 32408836 AB - This paper reports on an ongoing international effort to establish guidelines for numerical modeling of wave energy converters, initiated by the International Energy Agency Technology Collaboration Program for Ocean Energy Systems. Initial results for point absorbers were presented in previous work, and here we present results for a breakwater-mounted Oscillating Water Column (OWC) device. The experimental model is at scale 1:4 relative to a full-scale installation in a water depth of 12.8 m. The power-extracting air turbine is modeled by an orifice plate of 1-2% of the internal chamber surface area. Measurements of chamber surface elevation, air flow through the orifice, and pressure difference across the orifice are compared with numerical calculations using both weakly-nonlinear potential flow theory and computational fluid dynamics. Both compressible- and incompressible-flow models are considered, and the effects of air compressibility are found to have a significant influence on the motion of the internal chamber surface. Recommendations are made for reducing uncertainties in future experimental campaigns, which are critical to enable firm conclusions to be drawn about the relative accuracy of the numerical models. It is well-known that boundary element method solutions of the linear potential flow problem (e.g., WAMIT) are singular at infinite frequency when panels are placed directly on the free surface. This is problematic for time-domain solutions where the value of the added mass matrix at infinite frequency is critical, especially for OWC chambers, which are modeled by zero-mass elements on the free surface. A straightforward rational procedure is described to replace ad-hoc solutions to this problem that have been proposed in the literature. LA - English DB - MTMT ER - TY - JOUR AU - Clemente, D. AU - Rosa-Santos, P. AU - Taveira-Pinto, F. AU - Martins, P. TI - Influence of platform design and power take-off characteristics on the performance of the E-Motions wave energy converter JF - ENERGY CONVERSION AND MANAGEMENT J2 - ENERG CONVERS MANAGE VL - 244 PY - 2021 PG - 15 SN - 0196-8904 DO - 10.1016/j.enconman.2021.114481 UR - https://m2.mtmt.hu/api/publication/32406776 ID - 32406776 AB - E-Motions wave energy converter is a promising device capable of harnessing energy from wave/wind induced roll oscillations onto a generic floating platform, whose development was initiated with an experimental proof of-concept study that, despite demonstrating the potentialities of the device, also highlighted the need for further developments, aimed at improving its performance and efficiency. This justified a new phase of numerical modelling, where E-Motions was reproduced within the ANSYS (R) AQWATM environment, a potential theory based numerical model widely used in the field of wave energy converter development. The model was setup (first stage) and calibrated (second stage) with experimental data from a proof-of-concept study, carried out on a 1:40 geometric scale, with a good agreement being obtained for the hydrostatic properties (difference below 5%) and hydrodynamic roll response (minimum average error of 2.83 degrees). From a follow-up third stage, focused on comparing eight different hull solutions with similar natural roll periods, it was determined that the half-sphere and trapezoidal prism geometries produced the highest power outputs for the studied conditions (maximum average outputs of nearly 5 kW/m and 8 kW/m, respectively). These two designs were then adapted to a 1:20 geometric scale alongside an updated version of the half-cylinder, which served as a "control" case, and subjected to a final stage of numerical modelling centered on assessing the Power Take-Off's influence (namely through variable damping and mass) in their performance. Outcomes from this stage denote the necessity of a careful selection of Power Take-Off mass/damping combinations, as a disproportionate relationship could lead to scenarios where the conversion system would stall on one of the superstructure's sides, moving within a very limited range of the available sliding amplitude. Maximum average power output values reach nearly 24 kW, 30 kW and 18 kW for the half-cylinder, half-sphere and trapezoidal prism, respectively, with a follow-up experimental study being planned for the near future, in order to evaluate the validity of these results. LA - English DB - MTMT ER - TY - JOUR AU - Davidson, Joshua Patrick AU - Henriques, Joao C. C. AU - Gomes, Rui P. F. AU - Galeazzi, Roberto TI - Opening the air-chamber of an oscillating water column spar buoy wave energy converter to avoid parametric resonance JF - IET RENEWABLE POWER GENERATION J2 - IET RENEW POWER GEN VL - 15 PY - 2021 IS - 14 SP - 3109 EP - 3125 PG - 17 SN - 1752-1416 DO - 10.1049/rpg2.12204 UR - https://m2.mtmt.hu/api/publication/32404421 ID - 32404421 AB - The oscillating-water-column (OWC) spar-buoy is a type of wave energy converter that may exhibit undesirable large roll and pitch amplitudes caused by a dynamic instability induced by parametric resonance. The occurrence of this phenomenon not only reduces the power extraction but significantly increases the structural loads on the buoy, the turbine rotor and on the mooring system. The paper compares the parametric resonance behaviour of two configurations of an OWC spar-buoy using experimental data obtained in a wave flume at a scale of 1:100. The configurations investigated were: (1) closed and (2) fully open-air chamber. The experimental tests covered a wide range of regular and irregular waves, as well as in free decay experiments. Results showed that opening the air chamber reduces the coupling between the buoy and the OWC within, thus shifting the damped natural heave frequency of the system in comparison with the closed chamber configuration. This effect changes parametric resonance characteristics of the two configurations due to the coupling between roll/pitch and heave modes. Moreover, for specific wave frequencies, the occurrence of parametric resonance observed when the chamber is closed do not occur while the air chamber is fully open. These results suggest the possibility of controlling a pressure relief valve installed on top of the device to reduce parametric resonance whenever this dynamic instability is detected. LA - English DB - MTMT ER - TY - JOUR AU - Engsig-Karup, Allan P. AU - Laskowski, Wojciech L. TI - An efficient p-multigrid spectral element model for fully nonlinear water waves and fixed bodies JF - INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS J2 - INT J NUMER METH FL VL - 93 PY - 2021 IS - 9 SP - 2823 EP - 2841 PG - 19 SN - 0271-2091 DO - 10.1002/fld.5011 UR - https://m2.mtmt.hu/api/publication/32408827 ID - 32408827 AB - In marine offshore engineering, cost-efficient simulation of unsteady water waves and their nonlinear interaction with bodies are important to address a broad range of engineering applications at increasing fidelity and scale. We consider a fully nonlinear potential flow (FNPF) model discretized using a Galerkin spectral element method to serve as a basis for handling both wave propagation and wave-body interaction with high computational efficiency within a single modeling approach. We design and propose an efficient O(n)-scalable computational procedure based on geometric p-multigrid for solving the Laplace problem in the numerical scheme. The fluid volume and the geometric features of complex bodies is represented accurately using high-order polynomial basis functions and unstructured meshes with curvilinear prism elements. The new p-multigrid spectral element model can take advantage of the high-order polynomial basis and thereby avoid generating a hierarchy of geometric meshes with changing number of elements as required in geometric h-multigrid approaches. We provide numerical benchmarks for the algorithmic and numerical efficiency of the iterative geometric p-multigrid solver. Results of numerical experiments are presented for wave propagation and for wave-body interaction in an advanced case for focusing design waves interacting with a floating production storage and offloading. Our study shows, that the use of iterative geometric p-multigrid methods for the Laplace problem can significantly improve run-time efficiency of FNPF simulators. LA - English DB - MTMT ER - TY - JOUR AU - Giannini, Gianmaria AU - Lopez, Mario AU - Ramos, Victor AU - Rodriguez, Claudio A. AU - Rosa-Santos, Paulo AU - Taveira-Pinto, Francisco TI - Geometry assessment of a sloped type wave energy converter JF - RENEWABLE ENERGY J2 - RENEW ENERGY VL - 171 PY - 2021 SP - 672 EP - 686 PG - 15 SN - 0960-1481 DO - 10.1016/j.renene.2021.02.132 UR - https://m2.mtmt.hu/api/publication/32408835 ID - 32408835 AB - Oscillatory wave energy converters of the sloped type may allow absorbing power from ocean waves efficiently if a valid optimal design is used. In earlier studies, the optimized geometry for the CECO device was defined by implementing a simplified frequency-domain model. In this paper, that geometry is evaluated against the former one by taking into consideration a more realistic modelling approach and assessment scenario. The two geometries were benchmarked through a time-domain model, which allows taking into account realistic sea states and the use of end-stops to limit the amplitude of CECO motions. It was concluded that the optimized geometry allows extra energy production for most of the irregular sea states evaluated (45% more annual energy production). Performance indices were also used to compare the two geometries and it was concluded that the optimized geometry was particularly advantageous for the more energetic sea states. Overall, this study clearly shows that the choice of the generator rated power and end-stops span length are key aspects in determining realistically the annual energy production of sloped-motion wave energy converters. ? 2021 Elsevier Ltd. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Giorgi, Giuseppe AU - Sirigu, Sergej AU - Bonfanti, Mauro AU - Bracco, Giovanni AU - Mattiazzo, Giuliana TI - Fast nonlinear Froude-Krylov force calculation for prismatic floating platforms: a wave energy conversion application case JF - Journal of Ocean Engineering and Marine Energy J2 - Journal of Ocean Engineering and Marine Energy VL - 7 PY - 2021 IS - 4 SP - 439 EP - 457 PG - 19 SN - 2198-6452 DO - 10.1007/s40722-021-00212-z UR - https://m2.mtmt.hu/api/publication/32406760 ID - 32406760 AB - Computationally fast and accurate mathematical models are essential for effective design, optimization, and control of wave energy converters. However, the energy-maximising control strategy, essential for reaching economic viability, inevitably leads to the violation of linearising assumptions, so the common linear models become unreliable and potentially unrealistic. Partially nonlinear models based on the computation of Froude-Krylov forces with respect to the instantaneous wetted surface are promising and popular alternatives, but they are still too slow when floaters of arbitrary complexity are considered; in fact, mesh-based spatial discretisation, required by such geometries, becomes the computational bottle-neck, leading to simulations 2 orders of magnitude slower than real-time, unaffordable for extensive iterative optimizations. This paper proposes an alternative analytical approach for the subset of prismatic floating platforms, common in the wave energy field, ensuring computations 2 orders of magnitude faster than real-time, hence 4 orders of magnitude faster than state-of-the-art mesh-based approaches. The nonlinear Froude-Krylov model is used to investigate the nonlinear hydrodynamics of the floater of a pitching wave energy converter, extracting energy either from pitch or from an inertially coupled internal degree of freedom, especially highlighting the impact of state constraints, controlled/uncontrolled conditions, and impact on control parameters' optimization, sensitivity and effectiveness. LA - English DB - MTMT ER - TY - JOUR AU - Heydari, Zohreh AU - Shobeyri, Gholamreza AU - Najafabadi, Seyed Hossein Ghoreishi TI - Numerical investigation of solitary wave interaction with a flapper wave energy converter using incompressible SPH method JF - JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING J2 - J BRAZ SOC MECH SCI VL - 43 PY - 2021 IS - 3 PG - 18 SN - 1678-5878 DO - 10.1007/s40430-021-02883-z UR - https://m2.mtmt.hu/api/publication/32408841 ID - 32408841 AB - In this research, mesh-free incompressible smoothed particle hydrodynamics (ISPH) was used to study the oscillatory behavior of a flapper wave energy converter located at the end of a numerical tank under the impact of solitary waves. A two-step projection approach including prediction and correction steps was employed to conduct temporal discretization of the governing equations for inviscid fluid flows. At different times, the pressure fields were implicitly calculated by the ISPH method to solve a pressure Poisson equation (PPE) derived upon the enforcement of the incompressibility conditions. To the authors' knowledge, not many mesh-less numerical studies have been accomplished addressing different aspects of absorption of wave power using oscillating flappers. In this study, effects of different parameters, including solitary wave height, flapper spring stiffness, moment of inertia of the wall withstanding wave loads, initial angle of the flapper and initial longitudinal wave crest-flapper distance for a pair of solitary waves, were examined to analyze the wave energy absorption performance of the flapper. The results showed the necessity of adopting optimum spring stiffness to maximize the wave power absorption. Otherwise, wave overtopping may occur for sub-optimal spring stiffness values, while the absorbed wave power was lower than maximal for too rigid flappers. It was further found that the flapper oscillation period decreased with increasing the spring stiffness, with the other parameters imposing no significant effect on the period. As another finding, it was figured out that the moment of inertia of the downstream wall must be optimal to capture maximum wave power. The initial angle of the flapper was also found to be an important factor contributing to wave power absorption. The maximal absorbed wave power was achieved when a pair of solitary waves was flowing toward the flapper in such a way that the second wave hit the flapper at the end of the flapper period, causing some resonance phenomenon. Damping process of the oscillatory motion due to the flow viscosity and flapper friction was also considered. The results of the present work can be used to maximize the wave power absorption by adjusting the wave converter design considering the wave height, spring stiffness, moment of inertia and longitudinal distance of wave crest between two successive solitary waves. LA - English DB - MTMT ER - TY - JOUR AU - Kramer, Morten Bech AU - Andersen, Jacob AU - Thomas, Sarah AU - Bendixen, Flemming Buus AU - Bingham, Harry AU - Read, Robert AU - Holk, Nikolaj AU - Ransley, Edward AU - Brown, Scott AU - Yu, Yi-Hsiang AU - Tran, Thanh Toan AU - Davidson, Joshua Patrick AU - Horváth, Csaba AU - Janson, Carl-Erik AU - Nielsen, Kim AU - Eskilsson, Claes TI - Highly Accurate Experimental Heave Decay Tests with a Floating Sphere: A Public Benchmark Dataset for Model Validation of Fluid–Structure Interaction JF - ENERGIES J2 - ENERGIES VL - 14 PY - 2021 IS - 2 PG - 36 SN - 1996-1073 DO - 10.3390/en14020269 UR - https://m2.mtmt.hu/api/publication/31801208 ID - 31801208 N1 - Department of the Built Environment, Aalborg University (AAU), Thomas Mann Vej 23, Aalborg, 9220, Denmark Floating Power Plant (FPP), Park Allé 382, Vallensbæk, 2625, Denmark Sintex, Jyllandsvej 14, Hobro, 9500, Denmark Department of Mechanical Engineering, Technical University of Denmark (DTU), Nils Koppels Allé, Building 403, Kgs Lyngby, 2800, Denmark School of Engineering, Computing and Mathematics, University of Plymouth (UoP), Plymouth, Devon, PL4 8AA, United Kingdom National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway, Golden, CO 80401, United States Department of Fluid Mechanics, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest, 1111, Hungary Department of Mechanics and Maritime Sciences, Chalmers University of Technology (CTH), Gothenburg, 40482, Sweden Ramboll Group A/S, Hannemanns Allé 53, Copenhagen S, DK-2300, Denmark Research Institutes of Sweden (RISE), P.O. Box 857, Borås, SE-50115, Sweden Cited By :3 Export Date: 6 July 2022 Correspondence Address: Kramer, M.B.; Department of the Built Environment, Thomas Mann Vej 23, Denmark; email: mmk@build.aau.dk Funding details: U.S. Department of Energy, USDOE, DE-AC36-08GO28308 Funding details: Energistyrelsen, DEA Funding text 1: Funding: The work related to planning and analyzing the physical test results was funded by the Energy Technology Development and Demonstration Program (EUDP) under the Danish Energy Agency. NREL was funded by the U.S. Department of Energy under Contract DE-AC36-08GO28308. AB - Highly accurate and precise heave decay tests on a sphere with a diameter of 300 mm were completed in a meticulously designed test setup in the wave basin in the Ocean and Coastal Engineering Laboratory at Aalborg University, Denmark. The tests were dedicated to providing a rigorous benchmark dataset for numerical model validation. The sphere was ballasted to half submergence, thereby floating with the waterline at the equator when at rest in calm water. Heave decay tests were conducted, wherein the sphere was held stationary and dropped from three drop heights: a small drop height, which can be considered a linear case, a moderately nonlinear case, and a highly nonlinear case with a drop height from a position where the whole sphere was initially above the water. The precision of the heave decay time series was calculated from random and systematic standard uncertainties. At a 95% confidence level, uncertainties were found to be very low—on average only about 0.3% of the respective drop heights. Physical parameters of the test setup and associated uncertainties were quantified. A test case was formulated that closely represents the physical tests, enabling the reader to do his/her own numerical tests. The paper includes a comparison of the physical test results to the results from several independent numerical models based on linear potential flow, fully nonlinear potential flow, and the Reynolds-averaged Navier– Stokes (RANS) equations. A high correlation between physical and numerical test results is shown. The physical test results are very suitable for numerical model validation. LA - English DB - MTMT ER - TY - JOUR AU - Leary, Matthew AU - Rusch, Curtis AU - Zhang, Zhe AU - Robertson, Bryson TI - Comparison and Validation of Hydrodynamic Theories for Wave Energy Converter Modelling JF - ENERGIES J2 - ENERGIES VL - 14 PY - 2021 IS - 13 PG - 18 SN - 1996-1073 DO - 10.3390/en14133959 UR - https://m2.mtmt.hu/api/publication/32408831 ID - 32408831 AB - Dynamic Wave Energy Converter (WEC) models utilize a wide variety of fundamental hydrodynamic theories. When incorporating novel hydrodynamic theories into numerical models, there are distinct impacts on WEC rigid body motions, cable dynamics, and final power production. This paper focuses on developing an understanding of the influence several refined hydrodynamic theories have on WEC dynamics, including weakly nonlinear Froude-Krylov and hydrostatic forces, body-to-body interactions, and dynamic cable modelling. All theories have evolved from simpler approaches and are of importance to a wide array of WEC archetypes. This study quantifies the impact these theories have on modelling accuracy through a WEC case study. Theoretical differences are first explored in a regular sea state. Subsequently, numerical validation efforts are performed against field data following wave reconstruction techniques. Comparisons of significance are WEC motion and cable tension. It is shown that weakly nonlinear Froude-Krylov and hydrostatic force calculations and dynamic cable modelling both significantly improve simulated WEC dynamics. However, body-to-body interactions are not found to impact simulated WEC dynamics. LA - English DB - MTMT ER - TY - JOUR AU - Lelkes, János AU - Davidson, Joshua Patrick AU - Kalmár-Nagy, Tamás TI - Modelling of Parametric Resonance for Heaving Buoys with Position-Varying Waterplane Area JF - JOURNAL OF MARINE SCIENCE AND ENGINEERING J2 - J MAR SCI ENG VL - 9 PY - 2021 IS - 11 PG - 24 SN - 2077-1312 DO - 10.3390/jmse9111162 UR - https://m2.mtmt.hu/api/publication/32472076 ID - 32472076 LA - English DB - MTMT ER - TY - JOUR AU - Quartier, Nicolas AU - Ropero-Giralda, Pablo AU - M. Dominguez, Jose AU - Stratigaki, Vasiliki AU - Troch, Peter TI - Influence of the Drag Force on the Average Absorbed Power of Heaving Wave Energy Converters Using Smoothed Particle Hydrodynamics JF - WATER J2 - WATER-SUI VL - 13 PY - 2021 IS - 3 PG - 23 SN - 2073-4441 DO - 10.3390/w13030384 UR - https://m2.mtmt.hu/api/publication/32408838 ID - 32408838 AB - In this paper, we investigated how the added mass, the hydrodynamic damping and the drag coefficient of a Wave Energy Converter (WEC) can be calculated using DualSPHysics. DualSPHysics is a software application that applies the Smoothed Particle Hydrodynamics (SPH) method, a Lagrangian meshless method used in a growing range of applications within the field of Computational Fluid Dynamics (CFD). Furthermore, the effect of the drag force on the WEC's motion and average absorbed power is analyzed. Particularly under controlled conditions and in the resonance region, the drag force becomes significant and can greatly reduce the average absorbed power of a heaving point absorber. Once the drag coefficient has been determined, it is used in a modified equation of motion in the frequency domain, taking into account the effect of the drag force. Three different methods were compared for the calculation of the average absorbed power: linear potential flow theory, linear potential flow theory modified to take the drag force into account and DualSPHysics. This comparison showed the considerable effect of the drag force in the resonance region. Calculations of the drag coefficient were carried out for three point absorber WECs: one spherical WEC and two cylindrical WECs. Simulations in regular waves were performed for one cylindrical WEC with two different power take-off (PTO) systems: a linear damping and a Coulomb damping PTO system. The Coulomb damping PTO system was added in the numerical coupling between DualSPHysics and Project Chrono. Furthermore, we considered the optimal PTO system damping coefficient taking the effect of the drag force into account. LA - English DB - MTMT ER - TY - JOUR AU - Ropero-Giralda, Pablo AU - Crespo, Alejandro J. C. AU - Coe, Ryan G. AU - Tagliafierro, Bonaventura AU - Dominguez, Jose M. AU - Bacelli, Giorgio AU - Gomez-Gesteira, Moncho TI - Modelling a Heaving Point-Absorber with a Closed-Loop Control System Using the DualSPHysics Code JF - ENERGIES J2 - ENERGIES VL - 14 PY - 2021 IS - 3 PG - 20 SN - 1996-1073 DO - 10.3390/en14030760 UR - https://m2.mtmt.hu/api/publication/32408842 ID - 32408842 AB - The present work addresses the need for an efficient, versatile, accurate and open-source numerical tool to be used during the design stage of wave energy converters (WECs). The device considered here is the heaving point-absorber developed and tested by Sandia National Laboratories. The smoothed particle hydrodynamics (SPH) method, as implemented in DualSPHysics, is proposed since its meshless approach presents some important advantages when simulating floating devices. The dynamics of the power take-off system are also modelled by coupling DualSPHysics with the multi-physics library Project Chrono. A satisfactory matching between experimental and numerical results is obtained for: (i) the heave response of the device when forced via its actuator; (ii) the vertical forces acting on the fixed device under regular waves and; (iii) the heave response of the WEC under the action of both regular waves and the actuator force. This proves the ability of the numerical approach proposed to simulate accurately the fluid-structure interaction along with the WEC's closed-loop control system. In addition, radiation models built from the experimental and WAMIT results are compared with DualSPHysics by plotting the intrinsic impedance in the frequency domain, showing that the SPH method can be also employed for system identification. LA - English DB - MTMT ER - TY - JOUR AU - Saeidtehrani, Saghy AU - Karimirad, Madjid TI - Multipurpose breakwater: Hydrodynamic analysis of flap-type wave energy converter array integrated to a breakwater JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 235 PY - 2021 PG - 17 SN - 0029-8018 DO - 10.1016/j.oceaneng.2021.109426 UR - https://m2.mtmt.hu/api/publication/32408828 ID - 32408828 AB - Wave Energy Converter (WEC) development needs a thorough dynamic characterization of the device and tuning the design properties to harness the maximum power. This paper addresses this need by using experimentally validated numerical simulation for an array of flap-type WEC mounted on a surface of a breakwater as a coherent approach in sustainable coastal protection. The developed numerical model is combined with a parametric iteration procedure to find the optimized values of power take-off (PTO) coefficients, and the flap's distance from the breakwater. It is shown that tuning the design properties of flap-type WEC integrated into a coastal structure leads to high energy capture around 85 percent of the available power. It was found that the amplitude of oscillation is significantly affected by the presence of different frequencies resultant from standing waves, and the confined water between the flap and the breakwater. It turns out that by tuning the distance between the flap and the breakwater, the standing waves can be used for increasing the amplitude of oscillation and consequently power enhancement. LA - English DB - MTMT ER - TY - JOUR AU - Safonov, Vladimir L. AU - Bas, Derek A. AU - Berman, Diana AU - Rostovtsev, Yuri V AU - Roberts, James A. AU - Mcconney, Michael E. AU - Page, Michael R. TI - Adaptation of Fluctuating Magnetoacoustic System to External Signals JF - IEEE ACCESS J2 - IEEE ACCESS VL - 9 PY - 2021 SP - 80847 EP - 80853 PG - 7 SN - 2169-3536 DO - 10.1109/ACCESS.2021.3085301 UR - https://m2.mtmt.hu/api/publication/32408829 ID - 32408829 AB - The adaptation of systems to external influences is of broad interest. We study the influence of microwave signals of different shapes on the magnetoacoustic wave system with a giant nonlinearity in canted antiferromagnet FeBO3 at room temperature, which is close to its phase transition to the paramagnetic state. The classical nonlinear system obeys external deterministic signals; the modulation response describes the shape of these signals. In response to a noisy spectrum, the system shows self-organization, and mode competition selects one excited mode while suppressing others. With an increase in the power of the external signal, another self-organization is observed in the form of a narrow peak at the frequency of the fundamental minimum. This represents the first observation of the macroscopic quantum statistical phenomenon, Bose-Einstein condensation of magnetoacoustic wave quanta in a wave system with a high level of thermal fluctuations. The resulting picture of adaptation can analogously be transferred to many other adaptive wave systems, including large scale adaptive wave systems in the natural environment. LA - English DB - MTMT ER - TY - JOUR AU - Sergiienko, Nataliia Y. AU - Bacelli, Giorgio AU - Coe, Ryan G. AU - Cazzolato, Benjamin S. TI - A comparison of efficiency-aware model-predictive control approaches for wave energy devices JF - Journal of Ocean Engineering and Marine Energy J2 - Journal of Ocean Engineering and Marine Energy PY - 2021 PG - 13 SN - 2198-6452 DO - 10.1007/s40722-021-00214-x UR - https://m2.mtmt.hu/api/publication/32408825 ID - 32408825 AB - This paper compares four different formulations of model predictive control that attempt to maximise electrical power generated by a wave energy converter (WEC). Control laws include (1) pure maximisation of mechanical power, (2) maximisation of mechanical power with a control penalty factor, (3) maximisation of electrical power using power conversion efficiency, and (4) maximisation of electrical power using the full electro-mechanical model of a system. For this study, a wave-to-wire model is developed for a floating spherical buoy connected to a permanent magnet synchronous generator. The performance of the controllers, including the mechanical and electrical power outputs, is compared in irregular wave conditions for the unconstrained and force-constrained scenarios. The results demonstrate that the controller designed to maximise mechanical power is not suitable for practical applications and may lead to negative electrical power output due to the non-ideal power take-off efficiency. Moreover, the replacement of the power take-off dynamics by the efficiency coefficient does not guarantee the maximum electrical power production. LA - English DB - MTMT ER - TY - JOUR AU - Verao Fernandez, Gael AU - Stratigaki, Vasiliki AU - Quartier, Nicolas AU - Troch, Peter TI - Influence of Power Take-Off Modelling on the Far-Field Effects of Wave Energy Converter Farms JF - WATER J2 - WATER-SUI VL - 13 PY - 2021 IS - 4 PG - 20 SN - 2073-4441 DO - 10.3390/w13040429 UR - https://m2.mtmt.hu/api/publication/32408840 ID - 32408840 AB - The study of the potential impact of wave energy converter (WEC) farms on the surrounding wave field at long distances from the WEC farm location (also know as "far field" effects) has been a topic of great interest in the past decade. Typically, "far-field" effects have been studied using phase average or phase resolving numerical models using a parametrization of the WEC power absorption using wave transmission coefficients. Most recent studies have focused on using coupled models between a wave-structure interaction solver and a wave-propagation model, which offer a more complex and accurate representation of the WEC hydrodynamics and PTO behaviour. The difference in the results between the two aforementioned approaches has not been studied yet, nor how different ways of modelling the PTO system can affect wave propagation in the lee of the WEC farm. The Coastal Engineering Research Group of Ghent University has developed both a parameterized model using the sponge layer technique in the mild slope wave propagation model MILDwave and a coupled model MILDwave-NEMOH (NEMOH is a boundary element method-based wave-structure interaction solver), for studying the "far-field" effects of WEC farms. The objective of the present study is to perform a comparison between both numerical approaches in terms of performance for obtaining the "far-field" effects of two WEC farms. Results are given for a series of regular wave conditions, demonstrating a better accuracy of the MILDwave-NEMOH coupled model in obtaining the wave disturbance coefficient (K-d) values around the considered WEC farms. Subsequently, the analysis is extended to study the influence of the PTO system modelling technique on the "far-field" effects by considering: (i) a linear optimal, (ii) a linear sub-optimal and (iii) a non-linear hydraulic PTO system. It is shown that modelling a linear optimal PTO system can lead to an unrealistic overestimation of the WEC motions than can heavily affect the wave height at a large distance in the lee of the WEC farm. On the contrary, modelling of a sub-optimal PTO system and of a hydraulic PTO system leads to a similar, yet reduced impact on the "far-field" effects on wave height. The comparison of the PTO systems' modelling technique shows that when using coupled models, it is necessary to carefully model the WEC hydrodynamics and PTO behaviour as they can introduce substantial inaccuracies into the WECs' motions and the WEC farm "far-field" effects. LA - English DB - MTMT ER - TY - JOUR AU - Windt, Christian AU - Untrau, Alix AU - Davidson, Joshua Patrick AU - Ransley, Edward J. AU - Greaves, Deborah M. AU - Ringwood, John V. TI - Assessing the validity of regular wave theory in a short physical wave flume using particle image velocimetry JF - EXPERIMENTAL THERMAL AND FLUID SCIENCE J2 - EXP THERM FLUID SCI VL - 121 PY - 2021 PG - 13 SN - 0894-1777 DO - 10.1016/j.expthermflusci.2020.110276 UR - https://m2.mtmt.hu/api/publication/31798371 ID - 31798371 LA - English DB - MTMT ER - TY - JOUR AU - Windt, Christian AU - Davidson, Joshua Patrick AU - Ringwood, John V TI - Numerical analysis of the hydrodynamic scaling effects for the Wavestar wave energy converter JF - JOURNAL OF FLUIDS AND STRUCTURES J2 - J FLUID STRUCT VL - 105 PY - 2021 PG - 28 SN - 0889-9746 DO - 10.1016/j.jfluidstructs.2021.103328 UR - https://m2.mtmt.hu/api/publication/32404395 ID - 32404395 AB - Scaled model tests are an important step during the research and development of wave energy converters (WECs). While such scaled model tests in physical wave tanks are prone to undesired scaling effects due to e.g. mechanical artefacts and/or fluid effects, numerical wave tanks (NWTs) provide excellent tools for the analysis of WECs across a range of scales, overcoming the limitations of the physical test environment. Simultaneous scaling based on the Froude and Reynolds number is achievable in physical wave tanks only with significant effort, whereas NWTs allow the adjustment of fluid properties, such as viscosity, in an easy manner, thereby catering for Froude and Reynolds similarity. This study exploits the capabilities of a high-fidelity, computational fluid dynamics based, NWT and investigates the hydrodynamic scaling effects for the heaving buoy Wavestar WEC. Various test cases, relevant for WEC applications and with progressively increasing complexity, are considered to develop a comprehensive understanding of the scaling effects. Results show that significant scaling effects occur for the viscous component of the hydrodynamic loads on the WEC hull, while the system dynamics and total (viscous + pressure) loads are relatively unaffected by scaling effects. (C) 2021 The Author(s). Published by Elsevier Ltd. LA - English DB - MTMT ER - TY - JOUR AU - Zhang, Yi AU - Teng, Bin AU - Gou, Ying TI - Nonlinear modelling of a point-absorber wave energy converter based on the weak-scatterer approximation JF - OCEAN ENGINEERING J2 - OCEAN ENG VL - 239 PY - 2021 PG - 16 SN - 0029-8018 DO - 10.1016/j.oceaneng.2021.109924 UR - https://m2.mtmt.hu/api/publication/32746770 ID - 32746770 LA - English DB - MTMT ER - TY - JOUR AU - C. Subramanian, Susheelkumar AU - Dye, Michaela AU - Redkar, Sangram TI - Dynamic Analysis of Suction Stabilized Floating Platforms JF - JOURNAL OF MARINE SCIENCE AND ENGINEERING J2 - J MAR SCI ENG VL - 8 PY - 2020 IS - 8 SP - 1 EP - 22 PG - 22 SN - 2077-1312 DO - 10.3390/jmse8080587 UR - https://m2.mtmt.hu/api/publication/31401145 ID - 31401145 LA - English DB - MTMT ER - TY - JOUR AU - Dafnakis, Panagiotis AU - Bhalla, Amneet Pal Singh AU - Sirigu, Sergej Antonello AU - Bonfanti, Mauro AU - Bracco, Giovanni AU - Mattiazzo, Giuliana TI - Comparison of wave–structure interaction dynamics of a submerged cylindrical point absorber with three degrees of freedom using potential flow and computational fluid dynamics models JF - PHYSICS OF FLUIDS J2 - PHYS FLUIDS VL - 32 PY - 2020 IS - 9 SP - 093307 SN - 1070-6631 DO - 10.1063/5.0022401 UR - https://m2.mtmt.hu/api/publication/31801216 ID - 31801216 LA - English DB - MTMT ER - TY - CHAP AU - da, Silva Leandro SP AU - Sergiienko, Nataliia Y. AU - Cazzolato, Benjamin S. AU - Ding, Boyin AU - Pesce, Celso P. AU - Morishita, Helio M. TI - Nonlinear analysis of an oscillating wave surge converter in frequency domain via statistical linearization T2 - Proceedings of the ASME 39th International Conference on Ocean, Offshore and Arctic Engineering (OMAE2020) PB - American Society of Mechanical Engineers (ASME) CY - New York, New York SN - 9780791884416 PY - 2020 SP - V009T09A019 PG - 11 DO - 10.1115/OMAE2020-18510 UR - https://m2.mtmt.hu/api/publication/31801215 ID - 31801215 LA - English DB - MTMT ER - TY - JOUR AU - da, Silva Leandro SP AU - Cazzolato, Benjamin S. AU - Sergiienko, Nataliia Y. AU - Ding, Boyin AU - Morishita, Helio M. AU - Pesce, Celso P. TI - Statistical linearization of the Morison’s equation applied to wave energy converters JF - Journal of Ocean Engineering and Marine Energy J2 - Journal of Ocean Engineering and Marine Energy VL - 6 PY - 2020 SP - 157 EP - 169 PG - 13 SN - 2198-6452 DO - 10.1007/s40722-020-00165-9 UR - https://m2.mtmt.hu/api/publication/31801222 ID - 31801222 LA - English DB - MTMT ER - TY - GEN AU - Engsig-Karup, Allan P. AU - Laskowski, Wojciech TI - Efficient p-multigrid spectral element model for water waves and marine offshore structures PY - 2020 UR - https://m2.mtmt.hu/api/publication/31801212 ID - 31801212 LA - English DB - MTMT ER - TY - JOUR AU - Giorgi, Giuseppe AU - Davidson, Joshua Patrick AU - Habib, Giuseppe AU - Bracco, Giovanni AU - Mattiazzo, Giuliana AU - Kalmár-Nagy, Tamás TI - Nonlinear Dynamic and Kinematic Model of a Spar-Buoy: Parametric Resonance and Yaw Numerical Instability JF - JOURNAL OF MARINE SCIENCE AND ENGINEERING J2 - J MAR SCI ENG VL - 8 PY - 2020 IS - 7 PG - 17 SN - 2077-1312 DO - 10.3390/jmse8070504 UR - https://m2.mtmt.hu/api/publication/31383676 ID - 31383676 LA - English DB - MTMT ER - TY - JOUR AU - Papillon, Louis AU - Costello, Ronan AU - Ringwood, John V. TI - Boundary element and integral methods in potential flow theory: a review with a focus on wave energy applications JF - Journal of Ocean Engineering and Marine Energy J2 - Journal of Ocean Engineering and Marine Energy VL - 6 PY - 2020 SP - 303 EP - 337 PG - 35 SN - 2198-6452 DO - 10.1007/s40722-020-00175-7 UR - https://m2.mtmt.hu/api/publication/31801218 ID - 31801218 LA - English DB - MTMT ER - TY - CONF AU - Ringwood, J. TI - Wave energy control: status and perspectives 2020 T2 - 21st IFAC World Congress on Automatic Control - Meeting Societal Challenges PB - Elsevier Ltd. C1 - Berlin T3 - IFAC-PapersOnLine, ISSN 2405-8963 ; 53. PY - 2020 PG - 12 UR - https://m2.mtmt.hu/api/publication/31801219 ID - 31801219 LA - English DB - MTMT ER - TY - JOUR AU - Ropero-Giralda, Pablo AU - Crespo, Alejandro JC AU - Tagliafierro, Bonaventura AU - Altomare, Corrado AU - Domínguez, José M. AU - Gómez-Gesteira, Moncho AU - Viccione, Giacomo TI - Efficiency and survivability analysis of a point-absorber wave energy converter using DualSPHysics JF - RENEWABLE ENERGY J2 - RENEW ENERGY VL - 162 PY - 2020 SP - 1763 EP - 1776 PG - 14 SN - 0960-1481 DO - 10.1016/j.renene.2020.10.012 UR - https://m2.mtmt.hu/api/publication/31801213 ID - 31801213 LA - English DB - MTMT ER - TY - JOUR AU - Trueworthy, Ali AU - DuPont, Bryony TI - The Wave Energy Converter Design Process: Methods Applied in Industry and Shortcomings of Current Practices JF - JOURNAL OF MARINE SCIENCE AND ENGINEERING J2 - J MAR SCI ENG VL - 8 PY - 2020 IS - 11 PG - 49 SN - 2077-1312 DO - 10.3390/jmse8110932 UR - https://m2.mtmt.hu/api/publication/31801217 ID - 31801217 N1 - Export Date: 8 January 2021 LA - English DB - MTMT ER -