Publications

Floating photovoltaic (FPV) systems in coastal and nearshore regions are subjected to complex wave loads that significantly influence their hydrodynamic performance. In the future, industrial scale FPV projects can consist of numerous floating bodies that are too large to be modeled using existing modelling methods such as Computational Fluid Dynamics. Therefore, there is a need to develop data-driven rapid prediction approaches. This study presents a data-driven framework to predict the heave and pitch response amplitude operators (RAOs) of FPV arrays under different wave conditions. A verified simulation model is developed, generating a dataset that incorporates the key influencing factors, including incident wave angle, wavelength-to-floater-dimension ratio, and mooring type. Random Forest (RF) and Multilayer Perceptron (MLP) models are trained and optimized through grid search cross-validation, demonstrating that both models accurately capture the spatial distribution and magnitude of RAOs, with the MLP model showing superior generalization capability. Interpretability analysis further reveals that the wavelength-to-floater-width ratio is the dominant factor driving RAO responses, while appropriate mooring strategies can effectively suppress motions under extreme conditions. Compared with conventional hydrodynamic simulations, the proposed approach significantly reduces computational cost and enables rapid evaluation of FPV dynamic responses, which provides a potentially workable approach to facilitate various purposes of large-scale ocean solar projects, such as design, monitoring, and digital twins.

Solar energy is one of the fastest-growing contributors to the global energy market. Floating photovoltaic (FPV) systems have emerged as a promising solution to the land-use challenges faced by conventional solar farms. However, the extension of FPV systems to offshore environments is hindered by dynamic wave–structure interactions. Inspired by air-cushion vessels, this study proposes and experimentally validates a novel FPV platform supported by an inflatable air cushion that provides adjustable stiffness and passive damping through air compressibility and wave-induced volumetric deformation. The investigated platform adopts a symmetric structural configuration, which inherently mitigates asymmetric roll and yaw coupling to maintain a balanced hydrodynamic response and stable power generation under wave action. Wave tank experiments were conducted to evaluate the coupled hydro-elastic response, mooring loads, and power generation stability under varying wave heights. The results show that the air-cushion design can significantly reduce peak mooring loads by over 50% compared with the catamaran benchmark. The highest pressure of 20 mbar increases structural stiffness but causes wave-induced losses of up to 30%. Conversely, the lowest pressure of 5 mbar results in excessive compliance that amplifies pitch and heave motion. A moderate pressure of 10 mbar acts as the optimal damping condition within the tested pressure range, suppressing motion resonance while maintaining power output stability. These findings demonstrate the potential of air-cushion integration for offshore FPV adaptability.

Floating photovoltaic (FPV) systems offer a promising route for expanding solar generation in coastal and offshore water bodies. However, wave-induced motion, mooring loads, and inter-module forces govern their viability. Excessive motion reduces energy yield, amplifies connector and mooring tensions, and threatens long-term reliability, making accurate hydrodynamic prediction essential for design. Most current CFD studies focus on single-row floaters, typically barge or catamaran-type platforms connected by rigid or hinged connections, leaving the behaviour of multi-row FPVs with compliant inter-module connections largely unexplored. This study develops and validates a high-fidelity CFD framework for rope-mesh FPV arrays, implementing a novel in-memory spring-connector formulation within OpenFOAM's rigid-BodyMotion framework to represent compliant, tensioned rope connections. The approach is validated against wave tank experiments for both single-module and 2×2 array configurations. Validation demonstrates excellent accuracy, with heave and pitch RAO errors within 5-13% across wavelengths. The framework successfully captures multi-body interaction effects, including wave-field shielding that reduces aft-row response by upto 10%. Direct comparison demonstrates that conventional rigid joints underpredict pitch by over 20% and overestimate heave by 18%, while the spring connector maintains errors within 5-13%, confirming the necessity of force-based compliant coupling for accurate rope-mesh FPV prediction. Connector force analysis reveals that streamwise connectors experience forces 3-5 times larger than transverse connectors, with peak forces occurring at λ/L ≈ 2.5-3.5, where phase differences maximise differential motion between rows. These results establish streamwise connections as the critical design drivers for rope-mesh FPV systems under head-sea loading.

Floating solar farms have become one of the most promising options for offshore energy infrastructure, yet concerns about wave-induced loading on the structures continue to hold back stakeholders. This study explores the hydrodynamic performance of floating solar arrays using systematic Computational Fluid Dynamics (CFD) simulations, analysing the dynamic behaviour of different floater configurations of catamaran, barge, and the mix of these two. The dynamic responses of 3 × 3 multi-body arrays were evaluated under regular wave conditions with wavelength-to-length ratios (λ/L) ranging from 1.62 to 4.27. The analysis focused on quantifying the Response Amplitude Operators (RAOs) for heave and pitch motions, as well as mooring line forces, to assess stability and energy dissipation characteristics. Results indicate that the barge configuration provides superior wave energy blocking in short wavelengths, with the front row significantly reducing the motion responses of downstream rows, while the catamaran configuration exhibits more similar motion behaviours across the array, as its twin-hull geometry allows greater wave transmission. However, the catamaran configuration outperforms the barge in reducing RAO amplitudes and mooring forces in longer wavelengths, showing peak mooring loads up to 30% lower. A hybrid array combining an upstream row of barge floater with downstream catamarans was envisioned to integrate the wave-blocking effect of the barge with the motion stability of the catamaran units; however, simulation results show limited performance enhancement under the tested wave conditions. Overall, this study provides insights into floater configuration for offshore floating solar farms, informing design choices as the demand for large-array systems grows.

The transition towards Net Zero Emissions (NZEs) is being accelerated by hybrid renewable technologies such as Floating Photovoltaic (FPV) systems and marine current turbines, which combine solar panels and cross-flow marine turbines mounted on floating structures for near-shore applications. Despite their innovative potential, these renewable technologies face significant challenges in stability and durability due to the effects of wind, waves, and ocean currents. Therefore, a flexible mooring system is essential to address these challenges. This research examines the influence of variations in the number of mooring lines and wave direction on the hydrodynamic response of FPV systems. Utilizing a catenary mooring system consisting of anchors, mooring lines, floats, and connectors, the study evaluates various configurations to determine the optimal solution for enhanced motion stability. Computational Fluid Dynamics (CFD) simulations are employed to analyze the dynamic response of FPV systems under different environmental conditions, represented on a sea-state scale, with a focus on pure oscillatory motions: heave, roll, and pitch. The findings aim to provide valuable insights for the design and operation of more stable and efficient FPV systems in marine environments, thereby supporting the advancement of sustainable renewable energy.

Land availability constraints limit the installation of conventional ground-mounted solar installations. As a result, Floating Photovoltaic (FPV) systems are gaining popularity as an alternative to renewable energy generation. FPV consist of individual solar panels that are commonly symmetrical and modular. However, the hydrodynamic behaviour of FPVs in water surface waves is understudied to ensure their stability and optimal performance under varying environmental conditions. This literature review examines various modelling techniques applied in studying FPV hydrodynamics. Specifically, the application of Computational Fluid Dynamics (CFD) solvers and potential flow theory solvers is investigated for their effectiveness in capturing the behaviour of FPVs and mooring dynamics under the impact of wind and waves. The review highlights the advantages and limitations of each approach. Findings suggest that a combined CFD-potential flow approach offers a perfect balance between accuracy and computational efficiency, offering valuable insights into the performance of FPVs. However, extensive research is notably absent in hydrodynamic modelling for large-scale FPVs. This lack of research represents a significant gap in our current study on multiscale FPV systems.

The oscillating water column (OWC) is a type of wave energy converter (WEC) that captures the energy of incoming waves. As waves reach the structure, their movement causes the water within an enclosed chamber to oscillate, creating airflow that powers a turbine, generating electricity. This principle can be applied to the design of breakwaters, which can protect marine structures such as floating solar farms and wind turbines. This study involved designing two types of buoyancy chambers for the OWC-WEC and two underneath baffles with adjustable spacing. These configurations were tested in a wave tank to assess wave energy capture, wave attenuation, hydrodynamics, and mooring forces. The experimental results demonstrate that a baffle spacing of 1 m, combined with a V-type buoyancy chamber, significantly enhances the wave energy capture and wave attenuation performance of the OWC. This configuration achieves up to a 57.09 % increase in the capture width ratio and a maximum reduction of 20.88 % in the wave transmission coefficient. Furthermore, mooring line forces are reduced by 21.86 %, while the baffles effectively mitigate pitch motion. Notably, greater pitch reduction improves the capture width ratio. In conclusion, this study introduces a novel wave energy converter, providing key insights for future marine energy development. • Design of a novel wave energy converter based on the oscillating water column principle. •The effects of different spacings between baffles and the buoyancy chamber on performance were analysed. •Within the measurement range, the average of capture width ratio improved by 8.99 %, with a maximum improvement of 57.09 % •The transmission coefficient and mooring line force decreased by 20.88 % and 21.86 %, respectively.

Solar PhotoVoltaic (PV), as a clean and affordable energy solution, has become ubiquitous around the world. In order to install enough PV coverage to meet the demand of global climate action, there has been a growing research interest in deploying solar panels on abundant sea space. However, the harsh marine environment is holding stakeholders back with safety concerns. There is a necessity to ensure the reliability of FPV on seas. To facilitate research in this area, the present review scans all Floating PV (FPV) literature related to the ocean, with a focus on reliability and risk mitigation. It starts by presenting contemporary and potentially future FPV designs for seas, inventorying both mechanical and electrical components. Accordingly, possible risks in the system are discussed with the associate mitigations suggested. Subsequently, a series of protective approaches to assess offshore wind and wave loads on FPV are introduced. This is followed by a structural integrity review for the system’s fatigue and ultimate strength, accompanied by anti-corrosion, anti-biofouling, and robust mooring concerns. Finally, essential research gaps are identified, including the modelling of numerous floating bodies on seas, mooring methodology for enormous FPV coverage, the interactions between FPV and the surrounding sea environments, and remote sensing and digital twins of the system for optimal energy efficiency and structural health. Overall, this work provides comprehensive insights into essential considerations of FPV on seas, supporting sustainable developments and long-term cost reductions in this sector.

Floating photovoltaic (FPV) systems face complex multi-physics interactions from wave-induced hydrodynamics and solar variability, yet there is a lack of a digital framework to balance the large amount of data, modelling accuracy, and real-time adaptability. This study addresses this gap by developing an AI-driven digital twin framework that integrates physical experimentation, data integration, and neural network-based modelling. A novel FPV system was experimentally tested under 150 + scenarios in different solar irradiance and water wave conditions, capturing hydrodynamic, thermal, and power performances. A two-tier artificial neural network architecture was implemented, providing a high-fidelity model for detailed analysi and a reduced-order model for real-time applications. The virtual twin can predict key outputs, including heave, surge, pitch, mooring forces, PV temperature, and power output, which potentially reduces the need for sensors on the physical twin and provides more comprehensive information. In summary, the proposed digital twin framework enables remote monitoring, prediction, and intelligent management of FPV systems. Moreover, it holds the potential to support wave-adaptive panel control energy system management, and predictive maintenance. These functions position the digital twin as a core enabler for efficient, reliable, and scalable offshore solar energy deployment.

• Designed a floating solar WPT system and novel coupling mechanism for yachts, scalable to larger vessels. • Introduced a novel robotic docking system ensuring precise alignment in dynamic maritime conditions. • Achieved 82 % WPT efficiency, even under wave-induced motion, supporting maritime decarbonization. • Tested in a wave tank to validate the system’s potential for decarbonizing maritime transport. • Proposed a grid-independent floating solar WPT system for autonomous, clean energy maritime charging. The maritime industry is under increasing pressure to decarbonise, presenting an important pathway of transforming the power systems from conventional marine fuels to electric-based. This study proposes an innovative solution to support maritime decarbonisation through the integration of a floating solar clean energy harnessing and wireless power transfer (WPT) technology for electric vessels. The paper presents the design and experimental tests of the integrated system specifically, based on a model of an electric yacht. This study provides an in-depth analysis of application of floating solar to provides an off-grid wireless power transfer system that can scale for larger vessels such as ferries. The off-grid modularity proposed enables scalable, flexible, and sustainable energy delivery for maritime applications and decarbonisation with specific attention to challenges in WPT alignment and environmental condition. Simulations using ANSYS Maxwell were performed to model the magnetic field interactions and ascertain the optimal power transfer efficiency. Subsequently, a reduced-scale prototype system was designed, built and tested in a wave tank. The experimental results demonstrated efficient wireless charging with an average efficiency of 82 %, and the docking system proved effective in maintaining alignment even when the ship has wave-induced motions. The findings support the feasibility of using floating solar WPT systems for maritime vessels and pave the way to larger-scale studies.

Floating photovoltaic (FPV) systems offer a promising renewable energy solution, particularly for coastal waters. This preliminary numerical study proposes a single-array pentamaran configuration designed to maximize panel installation and enhance stability by reducing rolling motion. The study investigates the effect of mooring length on the motion behavior of FPV systems and actual line tension using the Boundary Element Method (BEM) in both frequency and time domains under irregular wave conditions. The results demonstrate that the mooring system significantly reduces all horizontal motion displacements, with reductions exceeding 90%. Even with a reduction of up to 51% in the unstretched mooring length, from the original design (304.53 m) to the shortest alternative (154.53 m), the motion response shows minimal change. This is supported by RMSE values of only 0.01 m/m for surge, 0.02 m/m for sway, and 0.09 deg/m for yaw. In the time-domain response, the shortened mooring line demonstrates improved motion performance. This improvement comes with the consequence of stronger nonlinearity in restoring forces and stiffness, resulting in higher peak tensions of up to 15.79 kN. Despite this increase, all configurations remain within the allowable tension limit of 30.69 kN, indicating that the FPV’s system satisfies safety criteria.

Most current analytical research on the hydroelastic interaction between water waves and submerged horizontal elastic plates remains within the scope of linear theory due to the underdevelopment of mathematical methods for solving nonlinear problems. To address this gap, this work employs an approach that combines computational fluid dynamics (CFD) with computational solid mechanics (CSM) to dynamically simulate the fully coupled nonlinear hydroelastic interactions between ocean waves and a submerged horizontal plate. This research highlights the significance of nonlinear point responses of a submerged horizontal plate under focused wave conditions. A phase-based harmonic separation method (i.e., phase-decomposition method) is used to isolate wave amplitude and force harmonic components in complex wave scenarios. This approach allows for the clean delineation of individual harmonics from the total wave force by controlling the phase of incident focused waves and is for the first time applied to the response analysis of elastic structures. This paper successfully used the phase-decomposition method to separate the individual harmonics of the point displacement of a horizontal elastic plate, directly demonstrating the significance of nonlinear responses. Additionally, the impact of plate rigidity, which relates to natural frequency, on nonlinear responses is investigated. The results indicate that plates with a certain dimensionless plate rigidity will exhibit more significant nonlinear responses. By cleanly separating each individual harmonic response, this study provides new insights into the nonlinear hydroelastic responses of a horizontal plate interacting with water waves and offers a new perspective on fatigue analysis, underscoring the importance of nonlinearity for future engineering designs.

Whilst floating photovoltaic (FPV) is gaining attention for ocean-based applications, their motion response in waves significantly affects structural integrity and power generation efficiency . In particular, FPV is expected to operate in arrays consisting of extensive solar panels, and thus, floating solar systems are required to be analysed with neighbouring devices connected by joints . This study investigates the seakeeping characteristics of two FPV systems in arrays, comparing conventional barge floats with twin-hull (catamaran) floats under various wave conditions. A systematic investigation using Computational Fluid Dynamics (CFD) was conducted for the hydrodynamic response of both isoslated-single-floater and multi-body (1 × 3) configurations in regular waves, with non-dimentional wavelength ratio ( λ / L) 1.62-4.27 to the floater length. Wave tank experiments were conducted to validate the CFD model, showing agreement with less than 10% discrepancies. The study focused on the multi-body behavior of heave and pitch Response Amplitude Operators (RAOs) and mooring line forces. Results show that the multi-catamaran configuration exhibited lower heave RAOs (by approximately 20°%) compared to multi-barge pontoons in long waves (λ/L > 2.47) while maintaining similar pitch responses. However, in shorter waves ( λ / L < 2), the catamaran configuration showed up to 15% higher RAOs than barge's. The multi-body arrangement demonstrated significant array effects, with the leading float experiencing 30% higher mooring loads than the trailing float. The leading float also experiences the highest mooring forces. As the wavelength ratio increases, the barge float's front mooring force increases dramatically, reaching nearly twice that of the catamaran at a ratio of 4.27. These findings align with the RAO results, indicating that the barge float is more wave-sensitive under long-wavelength conditions, whereas the catamaran demonstrates superior station-keeping with lower mooring forces. This work provides quantitative guidance for selecting appropriate floater forms for FPV applications based on expected wave conditions.

Maritime transportation contributes around 3% of global emissions. As global trade and manufacturing expand, the decarbonization of maritime operations becomes an urgent challenge. Ferry ports in the UK face significant barriers to energy transition, including limited grid capacity, lack of charging infrastructure, and constrained land availability. This study proposes the development of a Floating Photovoltaic (FPV) plant on the sea near the port to independently generate renewable electricity for charging electric vessels operating between UK and France. Four scenarios are analyzed, varying in energy generation targets and ground coverage ratios (GCRs). Energy performance is evaluated using the System Advisor Model (SAM), estimating electricity generation and battery energy storage system (BESS) requirements under limited solar irradiance. A comprehensive economic analysis examines capital expenditure (CAPEX), operational expenditure (OPEX), levelized cost of energy (LCOE), revenue, and payback periods. The study also assesses environmental benefits by quantifying emissions for FPV lifespan and compares them to diesel-based energy. Moreover, charging technologies are reviewed in relation to current technologies, and a logistics plan for integrating FPV systems and electric vessels is proposed. Results demonstrate that the FPV plant can minimize BESS requirements, and reduce payback periods to as little as 3.62 years, facilitating the pathway of ferry ports to achieve net-zero emissions by 2045, with an estimated reduction of tonnes of annually. This study is among the first to assess the feasibility of using FPV systems to charge electric vessels at a UK marine port, integrating real-world spatial constraints, phased deployment planning, and life-cycle environmental analysis. It also introduces the conceptual integration of floating wireless charging infrastructure, offering a forward-looking approach to maritime electrification.

The problem of wave interaction with multiple elastic plates floating near a sloping beach is considered, particularly resembling the case of a floating solar farm near a coast. The linearized shallow water theory is adopted to describe the motion of fluid. The Kirchhoff–Love plate theory is used to model the elastic plates. A highly efficient domain decomposition approach is applied to derive the solution. Particularly, the eigenfunction expansions are employed to establish the velocity potential in free surface fluid domains, while the Green function method is used to construct the velocity potential of the fluid domain covered by floating elastic plates. This approach can significantly reduce the number of unknowns in the velocity potential, especially when a large number of plates are involved. Extensive results and discussions are provided for the wave run-up on the beach, maximum deflection, and principal strain on the elastic plates. In particular, based on a wide space approximated solution, the oscillatory behaviour of the wave run-up vs the incident wavenumber is analysed, along with the corresponding physical mechanisms. Furthermore, apart from the frequency-domain results, time-domain analyses are also conducted based on a Fourier transform approach. Two different types of incident impulses are considered to interact with floating elastic plates near a beach, namely a Gaussian wave packet and a storm-type incident wave.

At present, energy transition is a reality in the journey towards achieving net zero emission. Among others, the development of floating solar photovoltaic (FPV) power plants is one of many possible renewable energy technologies that received considerable attention. One of the reasons for that is attributed to land acquisition which can lead to conflicts, whilst the use of sea is more flexible. Therefore, the development of floating solar PV situated at the near shore (later can be moved offshore) is promising particularly in order to withstand the harsh environment. The study aims to demonstrate such an innovative design of a floating structure and two types of hulls (monohull and twin-hull) are considered and focused on the seakeeping performance of the two bodies. BEM approach with Green-Function based on the 3-D diffraction panel method together with the use of the Joint North Sea Wave Project (JONSWAP) wave spectrum is carried out to accomplish the seakeeping characteristic. The final computational simulation results show that the twin-hull model has more advantages than the monohull design. The trend of the RAO pattern, response spectra, and significant response for heave and pitch motion represent only slight differences between the two proposed designs. However, substantial disparity emerges in roll motion, with the difference in response values in prevailing 0o -roll heading standing at 53%, 39%, 27%, and 18% for sea states 1 through 4, respectively. Moreover, in 45o wave heading (quartering sea) it demonstrates a slightly lower disparity compared to the 0o wave heading (following sea) through sea-state 1-4 standing for 50%, 37%, 24% and 16% respectively.

Floating breakwaters are widely applied on the ocean water surface to protect human infrastructure from the destructive power of waves. This study designs and investigates the performance of a novel symmetric-pontoon floating breakwater with a symmetric pair of hydrofoils. Based at the Cranfield Ocean Systems Laboratory, the system was constructed and tested in various wave conditions using different fin configurations. The floating structure was anchored using a symmetric four-point mooring system. The tested waves were regular and symmetric perpendicular to the propagating direction. Key parameters, including the attenuated wave amplitude, motions of the breakwater, and the mooring forces, were measured. The wave parameters utilised for testing covered 1.61–5.42 relative wavelength to structural length, with wave heights of 3 cm and 5 cm. Results showed the 90° fin configuration can reduce wave transmission by up to 74%, with the lowest mooring forces at 3.05 relative wavelength, enhancing the performance of wave energy dissipation and structural seakeeping. At 90° setup, the mooring force was lowest at 2.41 relative wavelength. This research can inform novel designs of breakwaters to improve protection abilities for coastal cities and offshore infrastructures, especially renewable energy systems.

Floating Photovoltaic (FPV) is considered as a highly promising clean energy solution. In recent years, FPV has been widely deployed in calm water around the world. However, to find available space for further expansion, FPV needs to be deployed in seas whilst the oceanic waves significantly influence the structural stability and energy performance. On one hand, wave loads may cause structural fatigue and damage. On the other hand, wave-induced rotations of a floating solar panel will vary its tilt angle to the sunlight and thus affect the power output. To explore the new research field of ocean-based FPV, this work first designed a novel catamaran FPV floater with a four-point mooring system. Comparative experiments were then conducted in a wave tank to compare its seakeeping ability with a conventional flat-plate floater. Besides, a breakwater structure was further introduced to enhance the stability of these two types of floaters. Detailed data on floater motions and mooring line forces were collected under monochromatic wave conditions. Extensive analysis was performed to evaluate the wave-mitigating performance of the breakwater, as well as the nonlinearity in the motion and force time histories. Overall, the work provides valuable experimental data and novel insights into the design of FPV floaters and breakwater protection, supporting long-term sustainability of FPV on the ocean. • Experimental tests for the hydrodynamics of floating solar systems. • Two types of floating solar structures were tested in a wave tank. • A novel catamaran floater shows superior hydrodynamic performance. • Each floating solar structure was tested with and without a breakwater addition. • The breakwater effectively reduces wave-induced loading and motions of the system.

Floating photovoltaic is predicted to be the most ubiquitous energy technology in the future, with global installations projected to reach 10 GW by 2030, potentially generating 13.5 TWh of clean electricity annually. The extrapolation of solar power plants from land-based to water-based requires interdisciplinary expertise from fields such as energy systems , hydrodynamics , structures, environments, and electrical engineering. To bridge the disciplines, the present review analyses existing floating solar related publications comprehensively. Initially, a comprehensive literature scan of over 900 publications is presented, selectively leading to approximately 400 papers included. Subsequently, three review sectors are presented: design, modelling, and environmental effects. These cover various structural components, system-air-water interactions, their modelling approaches, power output prediction, and potential impacts on the surrounding environment including vegetation and animals. Key findings suggest the potential for enhancing energy efficiency through water-based cooling techniques, innovative modularised designs to support upscaling, positive environmental impacts including artificial habitats, and the utilisation of advanced marine structure designs such as a breakwater to protect the solar systems from ocean wave loads. In addition, the levelised cost of electricity of various floating solar studies are presented, including both theoretical and practical projects. The levelised cost of electricity has been decreasing, to a level of 0.05–0.07 USD/kWh, making FPV increasingly competitive as a clean and affordable energy choice. Overall, this review aims to facillitate interdisciplinary research and projects on the booming floating photovoltaic industry .

There has been a significant interest in developing Flexible Wave Energy Converters (FlexWECs) that utilise structural deformations to generate electricity and mitigate destructive wave loads to the devices. In the meantime, FlexWECs are most likely to operate in an array format to enhance space usage and power output, as well as provide convenience for maintenance. In this context, the present paper develops a high-fidelity computational model to investigate the interaction of ocean surface waves with an array of seawall-type FlexWECs, which can meanwhile serve coastal engineering purposes. The fluid field is solved using the Navier-Stokes equations, and structural deformations are predicted using a nonlinear finite-element method. Hydroelastic interactions of up to seven deforming FlexWECs with the surrounding wave fields are demonstrated through systematic simulation cases. Based on the simulation results, analyses are conducted to investigate how the wave farm energy output is influenced by the gap between individual devices and the number of devices deployed. Accordingly, empirical design suggestions are provided. Overall, this work innovatively simulates the hydroelastic interactions between waves and multiple deforming structures, and the provided insights are useful for promoting the development of FlexWECs and their wave farms.

The growth and development of floating solar photovoltaic (FPV) power plants is a prominent topic within renewable energy technology. One reason contributing to this desired technology design concept is the possibility of land acquisition issues, whereas the usage of the ocean provides a greater technical alternative area. The objective of the research is to present an innovative design for a floating structure, focusing on investigating and comparing the seakeeping performance of several hull configurations: catamaran, trimaran, quadrimaran and pentamaran. The final computational simulation results indicate a linear negative trend in the motion response graphs, particularly in specific significant response values for heave (Global Z), roll (Global RX), and pitch (Global RY), as the hull configuration increases.

Floating photovoltaic (FPV) solar farms have gained significant research and industrial interest in recent years. However, to support its deployment in abundant ocean space, FPV is required to be protected against wave loading. Thus, the usage of a breakwater in front of a floating solar farm is particularly promising. In this work, a time-domain simulation model for an array of FPV solar units in heading and oblique waves was established. Following validation against experiments, the model was used to predict the wave-induced motion and loading responses of each floating solar unit in an array, first without a breakwater, and subsequently with a breakwater. By comparison, it was found that a breakwater can reduce the wave-induced motions of a floating solar farm by up to 56%, alongside up to 55% reduction of loading on the joints between FPV units. However, the breakwater is less effective in relatively long waves and could induce some increase in loading on joints, signifying future work to optimize the design of the breakwater based on the intended environmental condition. Overall, the present results provide insights into a practical breakwater solution for FPV in offshore and coastal conditions, supporting the long-term development of this industry.

Deformable wave energy converters have significant potential for application as flexible material that can mitigate structural issues, while how to design the dimensions and choose an optimal deployment location remain unclear. In this paper, fully coupled computational fluid dynamics and computational solid mechanics were used to simulate the dynamic interactions between ocean waves and a deformable wave energy converter. The simulation results showed that the relative length to wave, deployment depth and aspect ratio of the device have significant effects on the energy conversion efficiency. By calculating the energy captured per unit width of the device, the energy efficiency was found to be up to 138%. The optimal energy conversion efficiencies were achieved when the structure length was 0.25, 0.5 or 0.75 of the dominating wavelength and submerged at a corresponding suitable depth. The aspect ratio and maximum stress inside the wave energy converter showed a nonlinear trend, with potential optimal points revealed. The simulation approach and results support the future design and optimisation of flexiable wave energy converters or other marine structures with notable deformations.

Abstract Solar photovoltaic is predicted to be the most widely used energy method in the future. However, the expansion of solar panels is currently limited by scarce land and lake spaces. To meet the world’s future clean energy target, floating solar panels are expected to be deployed on abundant ocean space, but floating solar panels on the ocean will be subject to loads and motions induced by waves. In particular, a continuous rotation can cause the solar panel surface to constantly change its sunlight intake angle, which could lead to a loss of energy. To investigate this phenomenon, a novel interdisciplinary experimental facility has been established, where a solar simulator was installed on top of a wave tank. A floating solar unit is placed in high-concentration light beams and subject to wave-induced motions. Its motions are measured and related to the power output. It was found that the average power output oscillates due to the motions, and an evident power loss was shown by the rotational motion. For all the tested wave conditions, the highest pitch amplitude of 6.7° corresponds to a significant level of 12.7% average power loss. Overall, the work presents a novel experimental approach and results that can estimate power output for floating solar projects in wave environments. The results also highlight the importance of considering wave attenuation technologies to avoid direct wave interaction with floating solar units.

A study approach to the novel design of floating photovoltaic systems has been provided using CFD simulation to determine motion characteristics on irregular waves with the JONSW AP spectrum under various water conditions. The simulation included in the frequency domain, shows that the CFPV model exhibits more stable behavior compared to its alternative model. This is due to the findings that the SFPV model has motion excitation associated with its own RAO against the wave energy spectrum at a frequency of 2.13 rad/sec (SS-2). This leads to a significantly dominant difference in motion quality concerning the significant response motion parameter. The quality difference values can be distinguished as heave with a value of 0.26 meters, roll with a value of 4.19°, and pitch with a value of 1.27°.

Floating solar renewable energy is of enormous potential in Indonesia. This paper presents a comprehensive study of the design of Floating Photovoltaic (FPV) systems with Battery Energy Storage Systems (BESS) for three islands in Indonesia. These islands represent three typical scenarios in Indonesia (a) using a national grid powered by fossil fuel generators, (b) using a local grid powered by diesel generators, and (c) no grid at all. In-person surveys were conducted at these islands to collect data, and then FPV and BESS were designed to meet the demands of each island. Subsequently, the systems’ energy simulations were conducted using the System Advisor Model, demonstrating daily energy demand and supply in hour variation. Based on the results, a series of sustainability analyses were created from the aspects of economics, society, and the environment. The economic analysis demonstrated cost savings by using FPV to replace contemporary energy methods. The social analysis provides valuable insights into the local community, forming a demographic profile and obtaining perceptions and opinions regarding the new energy approach. The environmental analysis quantifies the potential CO2 emissions. Overall, the work provides valuable insights into the roadmap for implementing floating solar technologies in Indonesia which can also inform global ocean-based solar energy developments.

Whilst there is an interest in floating solar energy systems in coastal and offshore regions to utilise available sea space, they are subject to ocean waves that introduce constant momentum. Consequently, solar panels undergo periodic motions with the waves, causing a continuous change in tilt angle. The tilt angle variation is a sub-optimal process and leads to a loss of energy harnessing efficiency. To investigate this phenomenon, the present study innovatively installed a solar simulator on top of a wave tank. The solar simulator was used to generate high-strength light beams, under which, a floating solar unit was subject to periodic incident waves. Wave-induced motions to the solar system as well as the output power were measured. A systematic analysis of the results indicated that a floating solar unit can have significantly lower power output in waves, compared to its calm-water counterpart. An evident link was established between the wave-induced power loss and the wave-induced rotational movement of the panel. An empirical equation was derived which shows the power loss is predictable through the rotational amplitude. The results also highlight the importance of implementing wave attenuation technologies such as breakwaters to minimise wave-induced motions to floating solar systems. Overall, this research presents a novel experimental approach to assess the difference of floating solar power in ocean-wave versus calm-water scenarios, providing valuable insights for future solar projects on the ocean. • Floating solar panels with motions induced by ocean waves can lose energy due to varying tilt angle. • This work developed a new experimental facility, combining a solar simulator and a wave tank. • A floating solar system’s power output under the influence of wave-induced motions was tested. • To enable quick prediction of this power loss, an empirical equation is provided. • The application of breakwater with floating solar to minimise the wave-induced power loss is discussed.

Research interest in breakwater design has increased recently due to the impetus to develop marine renewable energy systems, as breakwaters can be retrofitted to harness wave energy at the same time as attenuating it. This study investigates a novel system of attaching a hinge baffle under a floating breakwater. The floating breakwater itself acts as a heaving wave energy converter, and meanwhile the hinge rotation provides a second mechanism for wave energy harnessing. A computational model with multi-body dynamics was established to study this system, and a series of simulations were conducted in various wave conditions. Both wave attenuation performance and energy conversion ratio were studied, using an interdisciplinary approach considering both coastal engineering and renewable energy. In particular, the performance of the proposed system is compared with contemporary floating breakwater designs to demonstrate its advantage. Overall, a useful simulation framework with multi-body dynamics is presented and the simulation results provide valuable insights into the design of combined wave energy and breakwater systems.

Given the advantages of flexible wave energy converters (FlexWECs), such as deformation-led energy harnessing and structural loading compliance, there has been a significant interest in FlexWECs in both academia and industries. To simulate the FlexWEC interaction with ocean surface waves, a 3D computational fluid-structure interaction approach is developed in this study. The fluid and solid governing equations are discretized using finite difference and finite element methods, respectively. An immersed boundary method is used to couple the two independent grid systems. A novel numerical technique is introduced to model the dielectric elastomer generator (DEG) as the power take-off (PTO). The wave energy capture performance is analysed for different PTO configurations and at various wave conditions. Based on the obtained results, the PTO damping coefficient and the relative wavelength range that maximizes the capture width ratio (CWR) are determined. The wavefield results also reveal the presence of wave-height enhancement and attenuation points around a single FlexWEC, providing potential site selection references when deploying multiple FlexWECs in an array.

Flexible wave energy converters (FlexWECs) have been gaining increasing research and industrial interest as their deformable nature can potentially remedy the structural issues that limit the development of rigid WECs. To maximise the usage of space and infrastructure and improve energy efficiency, FlexWECs are normally deployed in close proximity, where the wave interaction with one device can influence others, signifying the opportunity to obtain energy efficiency enhancement from the interactions. To investigate the power capture performance of a FlexWEC array, this study employed a validated three-dimensional high-fidelity computational method to simulate the wave interaction with three FlexWECs in various array arrangements including power-take off. Based on systematic simulation cases, the present work analysed the relation between the geometrical characteristics of an isolated FlexWEC's perturbed wave field and the array's overall energy capture efficiency. The constructive interaction of the array was found the strongest when the longitudinal and lateral spacings of the array were 0.6 and 1 times of incident wavelength respectively, with a 15 % enhancement of overall captured energy compared to three devices operating in isolation. Overall, this study provides insights into the fluid-structure interaction of waves with multiple deformable structures, facilitating the modelling and planning of FlexWECs. • A high-fidelity computational model for multiple 3D deformable wave energy converters has been developed. • Hydroelastic interactions between ocean waves and arrays of deformed structures are presented in detail. • The q -factor variation of each wave energy converter in an array is analysed, and the optimal arrangement is given. • Strong nonlinear behaviours are demonstrated in fluid, structure and power-take-off aspects.

COVID-19 has been pandemic since the early 2020 and many efforts have been carried out worldwide. Among others, managing the spread of pandemic has been focused on air transportation since the mobility of people has been more actively using aeroplane hence the possibility of infecting people is much higher. Despite less intense, efforts to minimise the blow-out of COVID-19 in sea transportation have also been conducted. The International Maritime Organization (IMO) released guidance such pretravel information to crews and customers The types of guidance include the following items, namely pre-departure, social distancing, the use of masks, personal hygiene, environmental hygiene, and training. In the case of Indonesia, similar direction is introduced and implemented to cargo and passenger vessels. The current paper discusses the Indonesian regulation of managing COVID-19, which is based on IMO/WHO guidance, together with its implementation in the daily activities of people in sea transportation. A survey questionnaire is made out to collect the relevant information. The discussion covers the implementation of such guidance to Indonesian cargo and passenger vessels difficulties in applying the regulation on those ships and the related solutions.

Modularized floating solar farms exhibit the potential to replace conventional steel-frame ones, effectively remedying hydroelastic issues of a very large floating structure through discrete modules with mechanical connections. However, the response of the discrete modules under cyclic wave loading has not been fully understood. This paper assesses the motion characteristics and expansibility of modularized floaters in waves, based on computational results from fluid–structural interaction simulations. A crucial factor, denoted as the ratio of frame length to wavelength R=Ls/λ, is determined to predict the motions of a large floating solar system in head waves. Results indicate that the motion characteristics is predictable based on the R value. The empirical relationship between the R value and the motion of every unit in an array is analyzed. In particular, the results calculated from using the multiple-rigid-bodies method are also compared with those from using the single-large-hydroelastic-body method, and it was found that these two results are similar when R &amp;gt; 1. This similarity allows for predicting the multi-hinged bodies' behavior in waves through a simplified hydroelastic approach. Overall, this study reports insights that are useful for the design and optimization of modularized solar farms and can help address cyclic loading and motion concerns for long-term durability.

This review paper presents a comprehensive analysis of the mechanical design and analysis of dynamic power cables for marine renewable energy applications, focusing on research from the last two decades. The review covers key aspects such as mechanical properties, failure mechanisms, fatigue analysis, experimental studies, local cable analysis, and global load analysis. The study aims to provide a concise summary of the state-of-the-art, identifying recent advancements and research gaps in the field. The methodology involves a systematic review of relevant literature, including journal articles, conference papers, and industry reports. The findings are synthesised to provide insights into the current understanding of power cable design and analysis, as well as to highlight areas requiring further research and development. The review is intended to serve as a valuable resource for researchers, engineers, and stakeholders in the marine renewable energy sector, contributing to the development of more reliable and cost-effective dynamic power cable solutions.

The problem of wave interaction with multiple adjacent floating solar panels with arbitrary types and numbers of constraints is considered. All the solar panels are assumed to be homogeneous, with the same physical properties, as well as modeled by using the Kirchhoff-Love plate theory. The motion of the fluid is described by the linear velocity potential theory. The domain decomposition method is employed to obtain the solutions. In particular, the entire fluid domain is divided into two types, the one below the free surface, and the other below elastic plates. The velocity potential in the free surface domain is expressed into a series of eigenfunctions. By contrast, the boundary integral equation and the Green function are employed to construct the velocity potential of fluid beneath the entire elastic cover, with unknowns distributed along two interfaces and jumps of physical parameters of the plates. All these unknowns are solved from the system of linear equations, which is established from the matching conditions of velocity potentials and edge conditions. This approach is confirmed with much higher computational efficiency compared with the one only involving eigenfunction expansion for the fluid beneath each plate. Extensive results and discussions are provided for the reflection and transmission coefficients of water waves, maximum deflection, and principal strain of the elastic plates; especially, the influence of different types and numbers of edge constraints are investigated in detail.

Floating solar panels installed on water reservoirs are gradually becoming an increasingly popular renewable energy scenario. When the reservoir gate is opened to release water, complex interactions between an incoming current and the floating panels will occur. In this paper, by modeling the entire floating panel structure as a thin elastic plate, a mathematical model based on the linearized potential flow theory is established to investigate such interactions. Extensive analyses are conducted on the wave profile and plate deflection, revealing significant fluid resonance phenomena at certain current speeds.

Despite its remoteness and hostile environmental conditions, the Arctic holds significant shipping lanes, such as the Northern Sea Route (NSR) and the Northwest Passage (NWP). Typically, merchant ships operate along these routes in summer only, when the dominating type of ice is broken ice. A challenge of operating in such ice conditions is that there is no cost- and time-efficient method for predicting the resulting ice resistance, which makes route planning difficult, among others. To address this challenge, we present and analyze two complementary approaches to predict ship resistance in broken ice, of which one is experimental and the other numerical. The experimental approach makes use of a type of non-refrigerated synthetic model ice made of polypropylene, which makes it possible to test how a ship behaves in broken ice using a conventional non-refrigerated towing tank rather than an ice tank. The numerical approach, in turn, is based on the CFD-DEM method and can be used to consider fluid effects, such as the changes in fluid velocity and ship waves, while the ship is moving ahead. Validation calculations against established empirical approaches indicate that both approaches are reasonably accurate.

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 cost-sharing 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.

Climate change in recent years has produced viable shipping routes in the Arctic. However, critical uncertainties related to maritime operations in the Arctic make it difficult to predict ship speeds in ice and, thus, the voyage time and fuel costs. Cost–benefit analysis of alternative Arctic routes based on accurate environmental condition modeling is required. In this context, this paper presents a holistic approach that considers the major voyage-related costs of a trans-Arctic route as an alternative to the conventional routes via the Suez Canal Route (SCR) for existing merchant ships. This tool is based on high-fidelity models of ship performance, metocean forecasting, and a voyage optimization algorithm. Case studies are performed based on a general cargo vessel in operation to quantify realistic expenses inclusive of all the major operational, fuel, and voyage costs of the specific voyages. A comparison is made between the total costs of the trans-Arctic route and SCR for different seasons, which proves the economic feasibility of the trans-Arctic route. Overall, this work can provide valuable insights to help policymakers as well as shipbuilders, owners, and operators to assess the potential cost-effectiveness and sustainability of future Arctic shipping, thereby better developing future strategies.

The rapid growth of marine renewables has led to the development of very large floating structures (VLFS) that are designed to operate in deep seas. It is significant to understand the mechanism of the coupled effects between deformable VLFS and catenary mooring system. This paper presents a time-domain hydro-elastic-moored model developed by integrating a quasi-static mooring module into a fully coupled Computational Fluid Dynamics (CFD) - discrete-module-beam (DMB) approach. The model is used to investigate the coupled effects between structural hydroelasticity and loose-type mooring systems on a deformable VLFS in waves. The mooring and hydroelasticity codes are validated separately and show favourable agreement with other numerical and experimental results. Then the coupled effects between the mooring system and structural hydroelasticity are evaluated by assigning various design parameters, i.e., VLFS structural stiffness and mooring stiffness. The numerical results, including dynamic motions, longitudinal vertical bending moments (VBMs) and mooring tension forces are presented and analysed. These results can be used to design a VLFS with mooring in medium-deep sea, and help with the conventional mooring design for a less-stiffness VLFS due to hydroelastic response.

Offshore crews often work near each other due to limited space, signifying a complex environment for the airborne transmission of the coronavirus (COVID-19). During offshore operations, a fishing vessel can be subjected to miscellaneous airflow conditions and will respond dynamically to ocean waves. To understand the risk of COVID-19 contagion, this research establishes a new computational model to analyse the airborne transmission of COVID-19 and develops effective mitigation strategies where possible. The concentration and coverage of coronavirus are scrutinised, considering typical airflows and wave-induced vessel motions. Furthermore, the COVID-19 infection risk is quantified using a probability index. The results show that the overall infection risk of a ship in tailwind is lower than in head or beam wind. Structural motions are for the first time coupled with the virus transmission, and it was found that the vessel's oscillating movement in waves can reinforce the virus concentration in close proximity to the infected person and may help diffuse the virus outside the proximal region. The presented findings can inform the airborne contagion risks and corresponding hygienic measures for maritime and offshore operations, facilitating long-term human health in seas.i

Wave farms consist of arrays of wave energy converters. However, ocean waves perturbed by one device will interact with its neighbouring devices, which can lead to more or less power yielded than operating the devices in isolation. Therefore, it is of significant interest to study the optimal layout and spacing to deploy multiple devices. In this work, a validated high-fidelity computational approach is used to study the optimal arrays of three oscillating wave surge converters by systematically varying the array arrangement in different wave conditions. The simulations demonstrate the wave interaction with multiple dynamic bodies and how this affects the overall power output. Furthermore, novel empirical rules are derived to design the optimal constructive layout for three devices in a given wave condition, and this can be extended to cases of numerous devices.

This paper investigates the hydroelastic response of a multi-patch floating photovoltaic (FPV) structure in water waves over a stepped seabed. The resonance conditions and underlying mathematical mechanism of FPV patches are explored based on the linear potential-flow theory and the thin-plate model. An implicit function of the open-water wavelength and the FPV patch's structural wavelength is derived. Resonance conditions occur in the FPV patch when the patch length and structural wavelength (rather than the water wavelength, as commonly believed) satisfy certain proportions. Mathematical derivations are conducted to interpret the value of each proportion. Two resonance conditions are recognized based on the mathematical structure of the solution. The effects of a stepped seabed and adjacent patches on the resonance conditions and hydroelastic behavior of FPV structures are also investigated. For a given stiffness parameter, the resonance conditions of FPV patches are solely determined by the water depth. The distance between adjacent patches does not alter the resonance conditions of each patch. Resonance occurs in the water body between two patches when the ratio of patch distance to water wavelength takes certain proportional values. A resonant water body tends to amplify the oscillation amplitude of both patches. However, when two FPV patches and a constrained water body reach their theoretical resonance conditions at the same time, the oscillation amplitudes of both the seaward patch and the constrained free surface are evidently suppressed. The transmitted waves of an FPV structure are largely determined by the dynamics of the leeward patch.

Abstract The awareness of the energy and climate crisis has accelerated the development of renewable energy sources. Photovoltaic (PV) solar power plants harvest clean solar energy and convert it to electricity, which will be one of the most promising alternatives to the power industry in the context of a low-carbon society. Due to its low power density, the traditional deployment of PV systems on land or inland rivers requires much space. Therefore, industries are increasingly interested in expanding offshore Floating PhotoVoltaics (FPV) to oceans, where FPV has less influence on the marine environment and does not occupy precious space for land resources and human activities. This study performs a hydrodynamics-based structural response analysis for a novel FPV system in OpenFOAM. The wave-proof FPV platform is newly designed for this work, which integrated breakwater technologies to sustain the system’s survivability in harsh ocean-wave environments. Firstly, the rational mooring types for FPVs installed close to the island are studied considering seabed effects. Subsequently, extensive parametric studies have been conducted to determine a rational design strategy for the mitigation of wave impact. Several potential effects of the proposed platforms on the hydrodynamics in a coastal sea are evaluated for the first time.

Offshore wind turbines are frequently regarded as a pricey source of electricity, and efforts are being made to lower both capital and operational costs by developing lighter and more robust structures. This paper presents a topology optimisation method to obtain a novel jacket foundation design by finding the optimum load path on the structure. The OC4 jacket model was computationally simulated considering the Aero-Hydro-Servo-Elastic loads, and the topology optimisation method was used to obtain a series of new designs. The structural optimisation is performed based on the dynamic response of the jacket, whilst restrained by relevant international design standards. In particular, time-domain fatigue simulations were performed to assess the structural integrity of the topology-optimised jacket for the first time. As a result, a range of optimised models with various thickness and diameter options are presented, which are shown to be rational and verify the optimisation procedure. The structural performance of the optimised geometry demonstrates the original jacket foundation is conservative, and the selection of optimised geometry achieved a mass reduction of 35.2% and simultaneously realised a 37.2% better fatigue life. The overall optimisation procedure and results provide useful practicalities for the design of offshore wind turbine foundations and potentially facilitate the structural integrity and cost reduction of the relevant industry.

Computational Fluid Dynamics (CFD) simulations of a ship’s operations are generally conducted at model scale, but the reduced scale changes the fluid behaviour around the ship. Whilst ideally ship simulations should be run directly at full scale, a guide has not been published to advise on the suitable setups that can provide accurate results while minimizing the computational cost. To address this, the present work explores an optimal approach for full-scale ship simulations. Extensive sensitivity studies were conducted on relevant computational setups to investigate their influences on the prediction of ship resistance, ship-generated waves as well as the boundary-layer flow of the hull. A set of CFD setups for full-scale ship simulations in open water was recommended. It was demonstrated that the ideal Y+ and Courant numbers in full scale are evidently different from those given in current model-scale CFD guidelines, indicating the necessity to establish full-scale CFD guidelines separately.

A free-rising buoyant sphere can break an ice plate floating above it. The problem is when the light sphere breaks the ice plate most, or the optimal relative density of the sphere which can break the ice plate the most severely. This experimental study was done to answer this problem. A set of experimental devices were designed, and a high-speed camera system was adopted to record the whole dynamic process, including the free-rising of the sphere, the collision between the sphere and the ice plate, the crack initiation and propagation, as well as the breakup of the ice plate. The failure mode of the ice plate under impact load was analyzed. It was found that conical cracks were formed under the reflected tensile wave at the top surface of the ice plate. On this basis, the influences of ice thickness, the initial submergence depth, and the relative density of the sphere on icebreaking were further investigated. An optimal relative density of the sphere was found when the sphere was released at a certain initial submergence depth, at which point the ice was damaged the most severely. For example, when the dimensionless initial submergence depth of the sphere was 2.31, the optimal relative density of the sphere was close to 0.4, with the probability of the ice plate breakup as high as 91.7%. It was also found from the experiments that the degree of damage to the ice plate correlated well with the kinetic energy of the sphere just before collision. Results showed that the optimal relative density can be estimated by theoretical analysis of the kinetic energy of the sphere, which will provide a reference for potential icebreaking applications in the future.

Apart from breaking level ice, polar ships can interact with broken ice in various scenarios. In recent years, computational simulation models have increasingly been used for the evaluation of ship operability under broken ice conditions, presenting some challenging issues. This paper reviews existing simulation methods used to estimate ship performance and ice loads for ships advancing continuously in broken ice fields. Models for different types of broken ice, including ice floes, ice ridges, brash ice, and sliding ice pieces, are reviewed separately. A ship’s response in broken ice is divided into two categories: resistance, which relates to the overall ship performance, and local loads, which relates to structural safety. This review shows that most existing models are proposed for unbreakable ice particles, which are only applicable to broken ice of small size; most models treat fluid flow with extensive simplification, which does not reflect the influence of a ship’s wake or bow waves, and most models are aimed at resistance estimation, adopting elastic or viscoelastic contact models which do not include ice crushing. As for future work, it is suggested that more effort should be assigned to simulating a ship’s interaction with ice ridges and sliding ice pieces, the modelling of breakable ice floes, and the coupling of the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD). More attention to the local ice load estimation is also encouraged.

The modelling of wave-structure interaction (WSI) has significant applications in understanding natural processes as well as securing the safety and efficiency of marine engineering. Based on the technique of Computational Fluid Dynamics (CFD) and the open-source simulation framework - OpenFOAM, this paper provides a state-of-the-art review of WSI modelling methods. The review categorises WSI scenarios and suggests their suitable computational approaches, concerning a rigid, deformable or porous structure in regular, irregular, non-breaking or breaking waves. Extensions of WSI modelling for wave-structure-seabed interactions and various wave energy converters are also introduced. As a result, the present review aims to help understand the CFD modelling of WSI and guide the use of OpenFOAM for target WSI problems.

Over the past decades, the underlying mechanism of level ice resistance changing with ship speed has not been fully understood, particularly the resistance component due to ship interactions with broken ice pieces. Pre-sawn ice test can negate icebreaking component from the whole resistance of a ship in level ice, providing an effective approach to decompose ship-ice interactions and investigate the speed-dependent resistance from broken ice pieces. This work has built a computational model that can realistically simulate a ship advancing in a pre-sawn ice channel. The model applies Computational Fluid Dynamics (CFD) to solve the flow around an advancing ship, which is coupled with an enhanced Discrete Element Method (DEM) to model pre-sawn ice pieces. Model-scale experiments have also been conducted at the Aalto Ice Tank to validate the simulations, which shows the computational model can provide a reasonable estimation of the pre-sawn ice's resistance and movement around the ship. Upon validation, the dependence of ice resistance on ship speed was analysed. The simulations enable underwater monitoring of the ice motions, indicating that the speed dependence results from the mass of ice submerged underneath the ship and the displacement of broken ice induced by the ship. The identified relationships are more complex than the widely-used assumption that ice resistance linearly changes with ship speed in all cases, which provides a deeper understanding of ice resistance. As such, the findings from this study can potentially facilitate improvements in relevant empirical equations, useful for ship design, operational strategies and maritime management in polar regions.

The global shipping industry has been severely influenced by the COVID-19 pandemic; in particular, a significant amount of passenger transportation has been suspended due to the concern of COVID-19 outbreak, as such voyages confine a dense crowd in a compact space. In order to accelerate the recovery of the maritime business and minimise passengers' risk of being infected, this work has developed a computational model to study the airborne transmission of COVID-19 viruses in the superstructure of a full-scale passenger vessel. Considering the vessel advancing in open water, simulations were conducted to study the particulate flow due to an infected person coughing and speaking, with the forward door open and closed. The results suggest that keeping the forward door closed will help prevent the external wind flow spreading the virus. When the forward door is closed, virus particles' coverage is shown to be limited to a radius of half a metre, less than a seat's width. Thus, an alternate seat arrangement is suggested. Furthermore, investigations were conducted on the influence of wall-mounted Air Conditioner (AC) on the virus transmission, and it was found that controlling the AC outlet direction at less than 15° downward can effectively limit the virus spread. Meanwhile, it was demonstrated that an AC's backflow tends to gather virus particles in a nearby area, thus sitting farther from an opening AC may reduce the risk of being infected. Overall, this work is expected to inform hygienic guidelines for operators to counter COVID-19 and potentially similar viruses in the future.

Abstract To investigate the operational improvements of vessels under the impact of COVID-19, this work has developed a Computational Fluid Dynamics model combined with Lagrangian particles to study the airborne transmission of COVID-19 viruses inside a ship. Initially a generic model was established to enable validation against experimental results for the diffusion of flu virus in an idealised room. Following this, the room geometry was replaced by the superstructure of a full-scale crew boat. Considering the boat advancing in open water, simulations were conducted to study the particulate flow due to a person coughing and speaking, with the boat’s forward door open and closed. The results have shown that, when the forward door is open, a significant airflow can carry the viruses to make extensive contacts with the passengers. This led to the suggestion of keeping the door closed. However, when the forward door is shut, face-to-face speaking can generate viruses that can float in the air for a long time, and it was found that the viruses mainly stay within a half-meter distance in front of the speaking person, before sinking to attach to the deck. Thus, a social-distancing suggestion on seat arrangement has been highlighted to minimise the risk of contagion. Overall, this work is expected to inform guidelines on hygienic and reconfiguring means for operators to counter COVID-19 and potentially the spread of similar viruses in the future.

During fishing operations, fishers often need to work in close proximity to each other on deck in a very limited space. This open-air working area can be subjected to various airflow conditions which might foster the airborne transmission of COVID-19 virus. To understand the risk of contagion in such a working environment and develop effective mitigation strategies to ensure the fishermen's safety, the present work establishes a computational model to analyse the virus' airborne transmission. Specifically, the work applies Computational Fluid Dynamic (CFD) to simulate various airflows occurring on an Indonesian fishing vessel, which is combined with Lagrangian particles that are used to model and track COVID-19 viruses. The concentration and coverage of COVID-19 viruses are analysed, considering the infected person working in different deck locations and under the influence of different vessel/wind speeds and directions. Subsequently, a set of guidelines including safe distance for the fishermen is suggested for each scenario.

Indonesia is one of the top three countries in the world for fisher fatalities due to a lack of stability monitoring, poor vessel design, and the fishers’ poor safety culture. Improved safety through technology, in particular stability awareness, has been identified as a key aspect to prevent capsizing and sinking. Despite the low technology uptake by Indonesian fishers, they are known to make extensive use of smart mobile phones as a primary form of communication. These phones are equipped with various sensors, including motion sensors that can be used by different mobile applications. This paper proposes the use of a mobile application to aid Indonesian fishers in assessing the stability of their vessel by using results from a roll decay test or realtime roll motion data monitored when operating at sea. For the pre-departure test, the mobile application uses the onboard gyroscope to record the roll angle time series which can then be used to quantify the roll period. An offline calculation is then carried out to approximate the vessel’s metacentric height. This is then visually presented using a traffic light system to provide the fishermen with a simple indication of whether the vessel is stable or not. Should the boat be unstable, additional guidance is provided to improve the vessel’s stability. The realtime monitoring system alerts the fishers when the thresholds are exceeded, to ensure realtime awareness of increased risk to the stability of the vessel.

Flexible Wave Energy Converters (WECs) have the potential to overcome contemporary drawbacks of rigid devices by mitigating structural problems and achieving high energy efficiency. This work introduces a fully-coupled simulation approach based on Computational Fluid Dynamics and Computational Solid Mechanics (CFD+CSM), by which the highly-nonlinear wave-structure interaction of flexible WECs is modelled for the first time. A flexible plate is analysed in both floating and submerged conditions, with various lengths considered. Complex wave-structure interactions are presented, and the plate's deformation is analysed to discuss the energy conversion efficiency. It is found that approximately 10%-60% of incoming wave energy may be harvested, though very sensitive to the device's length and submerged depth. Therefore, it is of great importance to perform appropriate design for flexible WECs and the present CFD+CSM approach provides a practical tool to do so.

Abstract A novel concept of wave attenuator is proposed for the defense of long waves, through integrating a flexible tail to the lee-side surface of a pile breakwater. The flexible tail works as a floating blanket made up of hinged blocks, whose scale and stiffness can be easily adjusted. A two-phase-flow numerical model is established based on the open-source computational fluid dynamics (CFD) code OpenFOAM to investigate its wave attenuation performance. Incompressible Navier—Stokes equations are solved in the fluid domain, where an additional computational solid mechanics (CSM) solver is embedded to describe the elastic deformation of the floating tail. The coupling of fluid dynamics and structural mechanics is solved in a full manner to allow assess of wave variation along the deforming body. The accuracy of the numerical model is validated through comparison with experimental data. Effects of the flexible tail on performance of the pile breakwater are investigated systematically. Dynamic behaviours of the tail are examined, and characteristics of its natural frequency are identified. For safety reasons, the wave loads impacting on the main body of the pile breakwater and the stress distribution over the tail are specially examined. It is found that both the length and stiffness of the tail can affect the wave-attenuation performance of the breakwater. A proper choice of the length and stiffness of the tail can greatly improve the long-wave defending capability of the pile breakwater. The maximum stress over the flexible tail can be restrained through optimising the deformation and stiffness of the tail.

Abstract The impact of breaking waves on an elastic vertical wall is investigated with a fully-coupled numerical model. The waves breaking on a 1:10 sloped bed is simulated with the computational fluid dynamics (CFD) approach with the stabilized k-ω model for turbulence closure. The deformations and stresses in the elastic vertical wall are investigated with the computational solid mechanics (CSM) approach. The CFD and CSM approaches are fully-coupled in the finite-volume-method-based OpenFOAM framework. The present approach is verified against an existing study of the interaction between non-breaking solitary waves and an elastic vertical wall. Good agreement is obtained. Then the breaking waves are simulated and their interaction with the elastic vertical wall is investigated. It is found that breaking waves can cause strong deformation and vibration of the elastic seawall. The oscillation frequency of the seawall is four times the wave frequency.

The shipping industry faces a large challenge as it needs to significantly lower the amounts of Green House Gas emissions. Traditionally, reducing the fuel consumption for ships has been achieved during the design stage and, after building a ship, through optimisation of ship operations. In recent years, ship efficiency improvements using Machine Learning (ML) methods are quickly progressing, facilitated by available data from remote sensing, experiments and high-fidelity simulations. The data have been successfully applied to extract intricate empirical rules that can reduce emissions thereby helping achieve green shipping. This article presents an overview of applying ML techniques to enhance ships’ sustainability. The work covers the ML fundamentals and applications in relevant areas: ship design, operational performance, and voyage planning. Suitable ML approaches are analysed and compared on a scenario basis, with their space for improvements also discussed. Meanwhile, a reminder is given that ML has many inherent uncertainties and hence should be used with caution.

Abstract Global warming has extensively transformed Arctic sea ice from continuous level-ice coverage to unconsolidated ice floe fields. Whilst the ice floes have a mixture of different sizes and their locations are randomly distributed, contemporary computational models lack effective methods to generate floe fields with such a natural pattern. This work introduces two original tools that can generate realistic ice floe fields for computational models. They are a sequential generator that sequentially handles ice floes one by one, and a genetic generator based upon a genetic algorithm. Demonstration of the tools is given, presenting samples of generating various shapes of floes and arbitrary mixtures of different shapes. Furthermore, an example is provided that combines the generated floe field with computational work modeling a ship transiting in ice floes. In addition, the source code of the tools is sharable to the public.

Abstract Pre-sawn ice test is the standard testing method to negate ice-breaking resistance from the whole resistance of a ship breaking level ice, which is of great importance for understanding ship-ice interactions and predicting various sea-ice loads on ships. This work has developed a computational model that can realistically simulate a ship advancing in a pre-sawn ice channel. The model applies Computational Fluid Dynamics to solve ship hydrodynamics, which is coupled with a novel particle-bonded Discrete Element Method to model pre-sawn ice pieces. Experiments were also conducted to validate the simulations. Upon validation, analyses were performed to investigate the ship-ice interaction. It was demonstrated that the pre-sawn ice resistance’s speed dependence has three regimes: for low ship speeds, the ice resistance slightly increases with decreased speed due to ice piling up; for middle ship speeds, the ship-ice interaction could remain similar and there is no distinctive change in the ice resistance; for high ship speeds, ice resistance evidently increases with increasing ship speed, which results from strong ship-ice collisions that cause ice pieces to move dramatically.

Abstract Ocean wave energy is significant and permanent, but it is extremely challenging to capture it efficiently using energy conversion technologies. Thus, research on these technologies and the hydrodynamic response of energy devices is constantly growing. One way of increasing the energy extracted from the ocean is to deploy wave farms consisting of arrays of wave energy devices; however, this is not as straightforward as extending the hydrodynamic response of one device. When the incident wavefield interacts with one device, it will be disturbed/modified by its presence, showing behaviours such as reflection, diffraction, and radiation. This perturbed wavefield will interact with neighbouring devices, and its influence can be beneficial or disadvantageous depending on the hydrodynamics. The q factor is commonly used to assess this interaction, which compares the power capture of a wave farm to that of the sum of the same number of devices performing in isolation. In this work, the q factor of configurations of three Oscillating Wave Surge Converters (OWSC), varying the spacing and arrangement, is predicted using Computational Fluid Dynamics. This resulted in beneficial layouts of three devices in different wave conditions, and the optimal array can be extended to numerous devices, which can be applied to the design of wave farms.

A computational fluid–solid dynamic model is employed to simulate the interaction between water waves and a consolidated ice cover. The model solves the Navier–Stokes equations for the ocean-wave flow around a solid body, and the solid behavior is formalized by the Maxwell viscoelastic model. Model predictions are compared against experimental flume tests of waves interacting with viscoelastic plates. The decay rate and wave dispersion predicted by the model are shown to be in good agreement with experimental results. Furthermore, the model is scaled, by simulating the wave interaction with an actual sea ice cover formed in the ocean. The scaled decay and dispersion results are found to be still valid in full scale. It is shown that the decay rate of waves in a viscoelastic cover is proportional to the quadratic of wave frequency in long waves, whilst biquadrate for short waves. The former is likely to be a viscoelastic effect, and the latter is likely to be related to the energy damping caused by the fluid motion. Overall, the modeling approach and results of the present paper are expected to provide new insights into wave–ice interactions and help researchers to dynamically simulate similar fluid–structure interactions with high fidelity.

The present paper introduces the development and verification of two ship performance models which have been implemented in a voyage planning tool designed for summer Arctic operations of commercial vessels. A novel ice resistance estimation algorithm for ice-floe conditions is implemented in the ship performance models. The fuel consumption predicted using both of the models are compared against full-scale measurements collected on a cargo ship of lower ice-class on the Northern Sea Route. This work found that both models meet the purpose of estimating ship fuel consumption for such a voyage planning tool and identified directions for future efforts. In addition, the typical transit scenarios in summer Arctic conditions presented in this study prove that a voyage planning tool with viable ship performance models facilitates Arctic shipping in a safe and sustainable way.

Please access through: https://agu2021fallmeeting-agu.ipostersessions.com/Default.aspx?s=18-3E-57-B4-48-68-8D-CB-81-7D-E6-F7-58-CA-CF-43

Abstract Numerical simulations are peformed to model the dynamic motions of a free floating body exposed to water waves. The solid body has low freeboard and draft, and its upper deck can be washed by the steep waves. Thus, the green water phenomenon occurs as large waves interact with the floating body. The aim of the research is to improve the understanding of the green water emerging above the upper deck of a floating plate. A thin floating body with barriers is also modeled. For the case of the body equipped with barriers, no green water occurs. Green water has been seen to affect the wave field and the dynamic motions of the plate. It is observed that when water can wash the upper surface of the floating object, drift speed is slightly decreased as a proportion of the energy of waves is dissipated above the body. Water waves are seen to impact the upper surface of the thin floating body as the green water flows over its upper deck. Furthermore, water is seen to impact the plate as its front edge re-enters the water. The first water impact only occurs when the floating body is not equipped with any barrier. By sampling the numerical simulations, it is observed that the non-dimensional value of the impact pressure, resulting from the green water, is larger for the case of smaller wavelength.

Underwater transportation is an essential approach for scientific exploration, maritime construction and military operations. Determining the hydrodynamic coefficients for a complex underwater transportation system comprising multiple vehicles is challenging. Here, the suitability of a quick and less costly semi-empirical approach to obtain the hydrodynamic coefficients for a complex transportation system comprising two Unmanned Underwater Vehicles (UUVs) is investigated, where the interaction effects between UUVs are assumed to be negligible. The drag results were verified by Computational Fluid Dynamics (CFD) analysis at the steady state. The semi-empirical results agree with CFD in heave and sway; however, they were overpredicted in surge due to ignoring the wake effects. Furthermore, experiments were performed for the validation of the time-domain motion simulations with semi-empirical and CFD results. The simulations which were performed with the CFD drags were close to the experiments. The semi-empirical approach could be relied on once a correction parameter is included to account for the interactive effect between multiple UUVs. Overall, this work makes a contribution by deriving a semi-empirical approach for the dynamic and controlling system of dual UUVs, with CFD and experiments applied to ascertain its accuracy and potential improvement.

Autonomous underwater gliders (AUGs) are currently deployed in oceans throughout the globe and are recording real-time, in-situ data. Simulating AUGs is rendered particularly difficult by the identification of the underlying dynamic model, as these vehicles embed several internal movable components. Acausal simulators can significantly improve the possibility to study and understand the dynamics of this class of vehicles and can in turn support the design of more robust control systems. In this paper, an open-source simulator architecture designed in OpenModelica is proposed to simulate underwater gliders. The validation is carried out using two different AUGs models, a ROGUE and a Seawing. The vehicle dynamics is firstly compared with analytical results and, following, with values obtained by means of another simulator. Further steps will entail comparing the dynamics of a simulated Seaglider with real deployment data publicly available. In this work, some of the main hydrodynamic and geometrical properties of a Seaglider are identified, computed through Computational Fluid Dynamics (CFD) analyses and retrieved from the mission ballast sheet. Overall, the developed model is expected to enhance gliders’ control strategies, thus improving their performance and mitigating incidents such as being carried away by undesired ocean currents.

The UCL OpenFOAM Workshop aims to help beginners to start using OpenFOAM for their projects, as well as to create a platform for experienced users to collaborate. It is free of charge and initiated as a UCL Doctoral Skills Development Programme. The workshop provides two types of sessions:(a) cutting-edge research, and(b) hands-on tutorials. This workshop is the unique event that has won the UCL Research-led Initiative Award three times in a row (2018, 2019 and 2020). Chair: Luofeng Huang

The seafaring and fishing industries in Indonesia have been severely affected by the COVID-19 pandemic. There is an urgent need to research the best technical solutions to ensure the safety of seafarers and fishers so that they can keep working safely at sea. It is highly unlikely that the Indonesian fleet will be able to rapidly return to the pre-COVID-19 situation within the next few years. Therefore, long-term solutions are required. This research aims to provide guidance for owners, operators and masters to reconfigure their vessels and operations to ensure a safe working environment to counter the potential spread of the virus, as well as maintaining the integral safety of the vessels. The present paper reports several primary activities, including analysis of existing guidelines, questionnaire survey, computational fluid dynamics, remote monitoring and machine learning. These works are expected to provide indications on virus-hazardous areas for ships, inform guidelines on hygienic and reconfiguring means to counter COVID-19 and potentially the spread of similar viruses, and further establish a long-term monitoring and optimising system for ship safety and performance.

Global climate change is presenting opportunities for new networks of maritime transportation through the Arctic. However, these sea routes are often infested by floating sea ice, which brings uncertainties to shipping operators, designers and builders. This work aimed to develop reliable simulation approaches for shipping scenarios in the presence of sea ice and investigate the associated changes to ship calm water resistance. For this purpose, computational fluid dynamics and ice solid mechanics were combined to model the potential ship-wave-ice interactions. Specifically, models were developed to simulate the two primary scenarios of a cargo ship operating in the Arctic, respectively a waterway with floating ice floes and an openwater channel created by icebreakers. Additionally, to build understanding of the Arctic sea condition, two other models were developed simulating the interaction of ocean waves with a rigid ice floe and then an elastic ice sheet, which provided a new solver capable of modelling hydroelastic fluid-structure interactions. Based on validation against experiments, these models provided the ability to accurately predict the ship-wave-ice interactions and the ice-induced resistance changes. Through conducting a systematic series of simulations, it was found that ice floes can increase the ship resistance by the same order of magnitude as the open water resistance, but this is strongly dictated by the ship beam, ice concentration, ice thickness and floe diameter. An open-water ice channel was found to increase the ship resistance by up to 15% compared to the situation without ice, particularly when the channel width is less than 2.5 times the ship beam and the ice thickness is greater than 5% of the ship draught. Moreover, this work developed a procedure to derive simple ice-resistance equations from the simulation results, enabling fast prediction of ship fuel consumption in sea ice fields and incorporation into a new Arctic Voyage Planning Tool.

The UK Institutional-links WSI Early Career Fellow programme aims to bring together excellent UK Early Career Researchers (ECRs) in the field of Wave Structure Interaction (WSI), thus forming highquality collaborations by improving experimental, computational and analytical skills as well as soft skills such as co-production and grant application. The programme consists of a series of workshops in different UK institutions. In 2021, two workshops were successfully held in Imperial College London and the University of Plymouth. The workshops were delivered in the form of themed seminars, observations of WSI experimental facilities and brainstorming potential collaborative ideas. These were followed by consultation with senior academic mentors to identify the key research questions and put action plans together. The fellows are developing a long-term partnership for collaborative research and resource sharing; the intended outcomes are top journal publications and joint research grants.

The shipping industry faces a significant challenge as it needs to significantly lower the amounts of Green House Gas emissions at the same time as it is expected to meet the rising demand. Traditionally, optimising the fuel consumption for ships is done during the ship design stage and through operating it in a better way, for example, with more energy-efficient machinery, optimising the speed or route. During the last decade, the area of machine learning has evolved significantly, and these methods are applicable in many more fields than before. The field of ship efficiency improvement by using Machine Learning methods is significantly progressing due to the available volumes of data from online measuring, experiments and computations. This amount of data has made machine learning a powerful tool that has been successfully used to extract information and intricate patterns that can be translated into attractive ship energy savings. This article presents an overview of machine learning, current developments, and emerging opportunities for ship efficiency. This article covers the fundamentals of Machine Learning and discusses the methodologies available for ship efficiency optimisation. Besides, this article reveals the potentials of this promising technology and future challenges.

To estimate the response of wave energy converters to different sea environments accurately is an ongoing challenge for researchers and industry, considering that there has to be a balance between guaranteeing their integrity whilst extracting the wave energy efficiently. For oscillating wave surge converters, the incident wave field is changed due to the pitching motion of the flap structure. A key component influencing this motion response is the Power Take-Off system used. Based on OpenFOAM, this paper includes the Power Take-off to establish a realistic model to simulate the operation of a three-dimensional oscillating wave surge converter by solving Reynolds Averaged Navier-Stokes equations. It examines the relationship between incident waves and the perturbed fluid field near the flap, which is of great importance when performing in arrays as neighbouring devices may influence each other. Furthermore, it investigates the influence of different control strategy systems (active and passive) in the energy extracted from regular waves related to the performance of the device. This system is estimated for each wave frequency considered and the results show the efficiency of the energy extracted from the waves is related to high amplitude pitching motions of the device in short periods of time.

Shipping water, the flow washing over and impacting the upper decks of ships and offshore structures, occurs frequently during their service life and often causes structural problems. For engineers to design safe floating structures subjected to shipping water it is essential to gain an in-depth understanding of its depth and flow field, and the resulting impact forces. In this work, Computational Fluid Dynamics (CFD) is applied to understand the physics of shipping water washing over a stepped platform. We find that the most accurate solutions are obtained with the k−ε turbulence closure. The hydrodynamic load generated by the shipping water is found to strongly depends on the kinematic energy of the water hitting the step. It is shown that with smaller values of the freeboard a more dynamic flow ensues, with a stronger vortex and larger velocity gradient resulting in deeper shipping water and a larger impact force.

Abstract With the effects of global warming, the Arctic is presenting a new environment where numerous ice floes are floating on the open sea surface. Whilst this has unprecedentedly improved Arctic shipping navigability and brought about significant opportunities, the interaction of such floes with ships has yet to be understood, thus hindering appropriate assessment of corresponding ship performance. This paper presents work on developing empirical equations to estimate the effects of such floes on ship resistance. Based on extensive data from validated computational simulations, the ice-floe resistance has been shown to correlate with ship beam, ship speed, ice concentration, ice thickness and floe diameter, and the regression powers of each the parameter on resistance are ascertained for a container ship. This leads to an empirical equation that can immediately predict ice-floe resistance in a given condition. The proposed approach has the potential to facilitate propulsion power estimates for Arctic shipping, as well as providing valuable insights into ship design for these environmental conditions.

Modern ice breakers, using new technology, are now able to create channels through level ice and clean out the ice fragments, resulting in an open-water channel between two large ice sheets. Whilst this negates the potential resistance increase on a following vessel due to interacting with the broken ice pieces, the ship performance will still be influenced by the two large ice sheets on either side. The effect of such ice sheets on ships has to date not been studied in detail, so the channel effect is usually ignored during ship design processes and power estimates. The present paper reports on work to develop a computational model to simulate a ship advancing in an open-water ice channel and investigate the associated ship-wave-ice interaction. Based on a series of simulations, this work how the ship resistance and wake change with ship speed, channel width and ice thickness.

For oscillating wave surge converters (OWSC) the incident wave field is changed due to the movement of the flap structure. A key component influencing this motion response is the Power Take-Off (PTO) system used. This paper examines the relationship between incident waves and the perturbed fluid field near the flap using the Computational Fluid Dynamics method by using Reynolds Averaged Navier-Stokes (RANS) equations. Further, it investigates the influence of a PTO system in the energy extracted from regular waves. Whilst this wave evolution is not significant in the effective power captured by a unit device, it is of great importance when performing in arrays as neighbouring devices may influence each other.

Rogue waves are short-lived large amplitude irregular waves that randomly occur in oceans and significantly affect the safety of marine structures. Most past research has focused on the formation of&#13;\nrogue waves and their interaction with fixed marine structures; in contrast, research on their interactions&#13;\nwith freely floating structures is somewhat lacking. This paper outlines work conducted to simulate the&#13;\nmotions of a floating structure induced by rogue waves based on OpenFOAM. Code development has&#13;\nincluded the generation of a rogue wave group and its incorporation with the overset mesh technique&#13;\nto allow a large displacement of the structure. Validation of the developed code has been conducted&#13;\nthrough comparing the motions of a floating body in regular waves with existing experimental data.&#13;\nInvestigations were then performed on the motions of the same floating body with different degrees of&#13;\nfreedom induced by rogue waves. The behaviour of the floating body is analysed in detail; for example,&#13;\nthe sway, heave and the persistent roll motions after the wave has hit the structure. In addition, the&#13;\nnumerical results of forces and moments of the moving body are compared with their fixed counterparts

With the increasing demand for Arctic Engineering purposes, Squire suggests current theories may have oversimplified the sea ice hydroelasticity, indicating the need to develop numerical models to obtain more realistic solutions. Numerical models have been reported capable of achieving a full coupling between waves and rigid floating ice. When an ice floe is relatively small to wavelength, it is valid for the floe to be considered as rigid, thus no need to solve ice deformations. However, in order to model the sea ice hydroelasticity, a Fluid-Structure Interaction (FSI) approach is required to obtain the structural solution of ice deformation and couple it with the solution of surrounding fluid domain, which requires further development of above models. To fill this gap, an FSI approach was developed based on the open-source code, OpenFOAM, and it has been validated in&#13;\nthe case of wave interaction with a finite ice floe. In this work, the developed model is extended to a very&#13;\nlong ice floe to study the semi-infinite scenario. Simulations are performed to present the wave-induced ice&#13;\ndeformation, with the attenuation of hydroelastic waves along the ice floe investigated.

Global warming is inducing sea ice retreat, which is opening new shipping routes and extending the accessible area for resource exploration. This encourages an increasing research interest in sea ice behavior. With the sea ice melting, level ice is broken up by waves propagated from the open ocean, resulting in an environment where both floating ice floes and waves exist. Such wave–ice interaction can bring significant influences on the potential human activities. This work presents a series of numerical simulations to predict the behavior of a circular ice floe forced by regular waves, with different wavelength and wave amplitude conditions being investigated. The numerical model was validated against experiments, and it revealed good accuracy in predicting the rigid body motion of an ice floe, including some extreme cases that are difficult to model by previous methods. Two specific behaviors were observed during the numerical simulations, namely overwash and scattering. Both behaviors are discussed in detail to analyze their linear/nonlinear effect on the ice floe motion. The applied model could be used to provide valuable estimations for arctic engineering purposes.

The effect of global warming is inducing sea ice retreat and transforming the Arctic into a navigable ocean. The melted ice cover can result in an environment where pancake-shaped ice floes are floating on sea surface; however, the effect of such an ice condition on ship performance has yet to be understood. This work develops a numerical model to predict the ship resistance in this typical case. Building on a traditional computational model for predicting ship hydrodynamics in open ocean, the Discrete Element Method is incorporated to include ice floes, so as to achieve ship-wave-ice coupling; thus, the simulation innovatively considers the influence of fluid flow on the interaction process. Following validation against experiments, the proposed model has been shown capable of accurately predicting ship resistance in pancake ice condition. Subsequently, the relationship of the resistance with ship speed, ice concentration and floe size is investigated.

Among wave energy conversion devices, the Oscillating Wave Surge Converter (OWSC) stands out as an ecient and stable solution. These devices are composed of a buoyant ap that rotates around a hinge xed close to the seabed. An ongoing challenge is to predict the hydrodynamic loads on the devices, as the device will at times operate under rough sea states, when wave slamming can cause high peak pressures. The aim of this study is to predict the peak pressure loads obtained during wave slamming using numerical simulations. To achieve this, a two-dimensional model of an OWSC within a Numerical Wave Tank (NWT) was developed in OpenFOAM. The model setup was based on an existent experimental test in which the OWSC was placed as a rigid body-tted ap, while the experimental wave was made using the cnoidal wave theory. The discretisation of the mesh surrounding the body was handled by using overset-mesh technology, allowing the high-amplitude rotations of the OWSC. Based on the built model, the interaction of waves with OWSC has shown to be reasonably simulated, and the process is analysed in detail. After validation against experiments, the model also shows good accuracies on predicting the peak pressure loads and the rotation of the ap, while it underestimates the negative peak velocities