Applied Ocean Research最新文献

{"title":"Performance improvement of a flapping foil energy harvester using a trailing edge rotating cylinder","authors":"Chongjie Huang,&nbsp;Yongfei Liu,&nbsp;Xiaojing Sun","doi":"10.1016/j.apor.2025.104788","DOIUrl":"10.1016/j.apor.2025.104788","url":null,"abstract":"<div><div>A novel method is proposed to enhance the oscillating airfoil energy extraction from wind or ocean current by utilizing a cylinder in lieu of the rear section of the airfoil. A CFD method is utilized to investigate how variations in both geometric configuration and motion parameters of a rotating cylinder located at the trailing edge affect the energy conversion efficiency of a flapping foil system. Findings indicate that at lower reduced frequencies, the primary contribution to energy output arises from the heaving motion of the foil. As the trailing edge cylinder's rotational speed ratio rises, the efficiency of energy extraction initially improves before subsequently declining, with peak performance occurring at an optimal speed ratio of 5. Conversely, at higher reduced frequencies, the pitching moment becomes the principal contributor to energy generation. The energy harvesting efficiency improves with the increase of the rotation speed ratio of the rotating cylinder. The optimal rotation speed ratio <em>i</em>_max is 10. Moreover, positioning the rotating cylinder at the rear section of the airfoil allows it to attain higher energy harvesting efficiency with a smaller rotation speed than when placed at the leading edge, suggesting greater potential for practical applications.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104788"},"PeriodicalIF":4.4,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-purpose offshore wind: A case study on integrating passive acoustic surveillance into infrastructure in the North Sea","authors":"Magnus Ferris ,&nbsp;Edward Clark ,&nbsp;Guillermo Jiménez Arranz ,&nbsp;Philippe Blondel ,&nbsp;Cormac Reale ,&nbsp;Alan Hunter ,&nbsp;Anna Young","doi":"10.1016/j.apor.2025.104791","DOIUrl":"10.1016/j.apor.2025.104791","url":null,"abstract":"<div><div>This study investigates the feasibility and effectiveness of integrating acoustic sensors into offshore renewable energy infrastructure for multi-purpose underwater monitoring, with a focus on detecting illegal fishing activity. Two North Sea sites (Dogger Bank and Buchan Deep) were analysed to assess acoustic detection capabilities over a frequency bandwidth from <span><math><mrow><mn>100</mn><mspace></mspace><mspace></mspace><mi>Hz</mi></mrow></math></span> to <span><math><mrow><mn>10</mn><mspace></mspace><mspace></mspace><mi>kHz</mi></mrow></math></span>. The main uncertainties in the modelling stem from limited knowledge of the sediment properties, and from the range of possible source levels. The work could therefore be expanded by considering a stochastic approach to these uncertainties if a specific site was taken forward for trials of the monitoring method. The results indicate that a single hydrophone attached to the turbine substructure can detect the activity of a fishing vessel within a range of 300 to <span><math><mrow><mn>400</mn><mspace></mspace><mi>m</mi></mrow></math></span> under average conditions, extending up to 2 to <span><math><mrow><mn>4</mn><mspace></mspace><mi>km</mi></mrow></math></span> under favourable conditions. Optimal detection frequencies were typically in the range of <span><math><mrow><mn>500</mn><mspace></mspace><mspace></mspace><mi>Hz</mi></mrow></math></span> to <span><math><mrow><mn>5</mn><mspace></mspace><mspace></mspace><mi>kHz</mi></mrow></math></span>. Detection performance is strongly influenced by ambient noise levels and sediment composition, while water depth has minimal impact. Seasonal variations significantly affect sound propagation, with a downward-refracting sound speed profile in the summer and attenuating sediments increasing propagation loss. This increased loss is offset by reduced ambient noise due to calmer sea states, resulting in longer detection ranges during the summer. The optimistic detection ranges align with or exceed typical turbine spacing, suggesting that a hydrophone-equipped wind farm could effectively monitor fishing activity across its footprint. Coverage would not extend beyond its boundaries into adjacent Marine Protected Areas.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104791"},"PeriodicalIF":4.4,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The performance of bow foils in irregular and oblique waves","authors":"J.A. Bowker,&nbsp;N.C. Townsend","doi":"10.1016/j.apor.2025.104789","DOIUrl":"10.1016/j.apor.2025.104789","url":null,"abstract":"<div><div>Bow foils are an emerging energy saving device that utilise wave energy to improve the efficiency of ships operating in waves, through both a reduction in ship motions and the generation of additional thrust. To identify the performance of bow foils in oblique waves, this paper presents and compares experimental results from a series of free-running model tests, with and without a bow foil, with constant forward speed, in regular and irregular oblique waves. The experiments identify the effect of bow foils on the ship heave and pitch motions, shaft torque and revolutions and foil forces and motion, over a range of relative wave headings. The results, demonstrating the ITTC QNM method, show that the bow foil reduces the delivered power required to maintain a given speed in waves, and are effective across a range of heading angles, modal periods, and wave height once a threshold is reached. The results also verify the use of spectral approaches to predict the performance of bow foils in irregular waves using transfer functions and identify that the greatest power savings are achieved in head wave conditions. The presented results provide a holistic design methodology to predict and scale the performance of bow foils across a range of sea states.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104789"},"PeriodicalIF":4.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laboratory investigation of shape and initial orientation effects on surf zone object migration","authors":"Temitope E. Idowu ,&nbsp;Jack A. Puleo","doi":"10.1016/j.apor.2025.104784","DOIUrl":"10.1016/j.apor.2025.104784","url":null,"abstract":"<div><div>Discarded objects like munitions in marine environments pose public safety risks. The behavior of various density objects deployed at four cross-shore positions in the surf zone of a large-scale 120 m x 5 m x 5 m wave flume were observed under different forcing conditions. Net migration was predominantly directed offshore, with approximately 70 % offshore migration observed near the outer surf zone. Density, shape, and initial orientation were identified as important to object behavior, with density acting as the dominant driver in 67 % of the object pairing scenarios. The influence of shape and initial orientation on net migration decreases as near-bed forcing increases from the outer to the inner surf zone. Near the outer surf zone, tapered objects migrated longer distances in 89 % of the pairings than the more symmetric cylinders. Near-instantaneous observations provided by internal inertial motion units further suggest that density impacted object migration distance, migration duration, and motion initiation. The migration distance and duration of a less-dense object were up to ∼15 and ∼10 times that of a denser object in the inner surf zone. Faster migrations were observed on moderate slopes than flat areas, underscoring the role of local bed slope. The observations corroborate prior findings on the influence of density while challenging some shape-dependent migration patterns. The investigation offers detailed insights into the roles of shape and initial orientation on object net migration, and the near-instantaneous response of objects to wave action in the surf zone.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104784"},"PeriodicalIF":4.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative experimental study of the hydrodynamic force on a solid heave plate, and on heave plates with regularly distributed and fractally distributed perforations","authors":"Antonio Medina-Manuel ,&nbsp;Trygve Kristiansen ,&nbsp;Adolfo Maron-Loureiro ,&nbsp;Rafael Molina Sánchez ,&nbsp;Antonio Souto-Iglesias","doi":"10.1016/j.apor.2025.104787","DOIUrl":"10.1016/j.apor.2025.104787","url":null,"abstract":"<div><div>The hydrodynamic coefficients (added mass and damping) of oscillating solid and perforated heave plates were investigated using model-scale experiments. Discs with regularly distributed circular holes of various diameters, but with the same overall perforation ratio, were used. Additionally, a fractal geometry incorporating holes of all these diameters was examined. The experiments were conducted in a towing tank using heave force oscillation tests and decay tests using a single degree of freedom mechanism. Potential flow computations performed with WAMIT are also presented. The experimental results are compared to numerical data available in the literature, which suggested that the fractal plate lead to slightly larger damping –a trend not observed in the present study–.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104787"},"PeriodicalIF":4.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A method for clustering ship driving styles in head-on situations using collision avoidance behaviour characteristics","authors":"Moxuan Wei,&nbsp;Feixiang Zhu,&nbsp;Yifan Du,&nbsp;Yihan Niu,&nbsp;Tao Hu","doi":"10.1016/j.apor.2025.104786","DOIUrl":"10.1016/j.apor.2025.104786","url":null,"abstract":"<div><div>Currently, there are limited researches on objective demonstration and mining methods concerning the existence of ship driving styles. This paper proposes a method for clustering ship driving styles in head-on situations using collision avoidance behaviour characteristics. Firstly, the head-on situations are screened based on relative motion parameters between ships. Secondly, the improved sliding window algorithm is employed to detect the collision avoidance decision-making moment, considering the ships’ manoeuvring performance and navigation inertia. Then, collision avoidance characteristic indicators are selected, which combine the four collision avoidance requirements of ”early, large, wide, clear” proposed by the International Regulations for Preventing Collisions at Sea (COLREGs). Finally, a combination of factor analysis and the K-means<span><math><mrow><mo>+</mo><mo>+</mo></mrow></math></span> algorithms is utilized to effectively classify and characterize ship driving styles. Empirical findings derived from Automatic Identification System (AIS) data in the Laotieshan Waterway demonstrate that ships can be categorized into four distinct driving styles: Conservative Close-Distance Avoidance (CCDA), Delayed Low-Efficacy Avoidance (DLEA), Proactive Large-Amplitude Avoidance (PLAA) and Preventive Safe-Distance Avoidance (PSDA), which account for 50%, 26%, 15%, and 9% of the total, respectively. The proposed method provides a novel research perspective and certain practical application value in comprehending the micro-behavioural traits of ships and advancing the field of Maritime Autonomous Surface Ships (MASS).</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104786"},"PeriodicalIF":4.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive fuzzy sliding mode control for velocity regulation of subsea pipeline pigs with supervisory fuzzy tuning","authors":"Shufan Zhang ,&nbsp;Haokun Wang ,&nbsp;Gang Wen ,&nbsp;Shimin Zhang ,&nbsp;Xiaoxiao Zhu","doi":"10.1016/j.apor.2025.104782","DOIUrl":"10.1016/j.apor.2025.104782","url":null,"abstract":"<div><div>Stable velocity regulation of subsea pipeline pigs is critical for safe and efficient oil and gas operations, yet remains challenging due to strong nonlinearities and severe external disturbances such as slug flows and friction fluctuations. Therefore, this study proposes an adaptive fuzzy sliding mode control strategy, featuring a supervisory fuzzy mechanism that adaptively tunes the gains of the sliding mode reaching control law. This novel approach integrates a PID-based sliding surface and adaptive fuzzy inference, enhancing the controller’s robustness against system uncertainties and environmental disturbances. Simulations conducted on steeply inclined and curved pipeline scenarios—subjected to abrupt and severe disturbances—demonstrate that the proposed AFSMC exhibits faster regulation, less overshoot, and smoother valve transition compared to conventional controllers. The adaptive structure ensures stable pig velocity even under harsh and unpredictable subsea conditions. These results show that the AFSMC method improves control accuracy and system reliability, providing a practical solution for robust and stable pigging operations in complex offshore pipelines.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104782"},"PeriodicalIF":4.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-objective optimization of the Myring-style shape considering direct sailing resistance and flow-induced noise","authors":"Feng Liu,&nbsp;Zhen Sun,&nbsp;Hailin Quan,&nbsp;Peihan Zhu","doi":"10.1016/j.apor.2025.104785","DOIUrl":"10.1016/j.apor.2025.104785","url":null,"abstract":"<div><div>This study addresses the shape optimization of underwater vehicles and proposes a design optimization scheme for the Myring-style shape by incorporating direct sailing resistance and flow-induced noise. Numerical simulation methods for the resistance and flow-induced noise are established, and their effectiveness is validated. Integrating CATIA and STAR-CCM+ within the modeFRONTIER platform enables the parametric design of the Myring-style shape,and the calculation of flow-induced noise was accomplished through the automated analysis based on resistance. Representative surrogate models are tested and compared; high-accuracy models for resistance and flow-induced noise are consequently identified. A multi-objective optimization model based on the Kriging framework is then constructed for the Myring-style shape. Using the nondominated sorting genetic algorithm II, multi-objective optimization is performed. Comparative results indicate that relative to the initial design, the Pareto front solutions are improved for some objectives, with certain solutions achieving enhancements across all objectives, thereby validating the effectiveness of the proposed optimization process.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104785"},"PeriodicalIF":4.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimising sediment resuspension processes for improved modelling of solid waste in coastal aquaculture","authors":"Jiaqi Zong,&nbsp;Scott Hadley","doi":"10.1016/j.apor.2025.104780","DOIUrl":"10.1016/j.apor.2025.104780","url":null,"abstract":"<div><div>Modelling sediment resuspension in shallow and dynamic coastal marine environments requires a quantification of the combined shear stresses from waves and currents acting on the seabed. Predicting resuspension is essential when evaluating aquaculture-environment interactions from open-cage salmon pens. In this study, we used observations of waves, water currents and sediment properties from two coastal marine sites in southeast Tasmania, Australia, to assess the relative importance of currents and waves in driving resuspension based on two wave-current bottom shear stress models: a conventional linear superposition approach and an alternative formulation incorporating nonlinear wave-current interactions. Both models showed that wave-induced shear stress (<span><math><msub><mi>τ</mi><mi>w</mi></msub></math></span>) was the dominant driver of resuspension and the current-induced shear stress (<span><math><msub><mi>τ</mi><mi>c</mi></msub></math></span>) was comparatively unimportant. We then applied these shear stress estimates to parameterise a 1D sediment model Globosed and validated its predictions against in situ turbidity measurements. The results demonstrate that both linear and non-linear simulations captured resuspension trends observed in the field. The linear model, however, exhibited limited sensitivity to low suspended solid periods, whereas Globosed showed improved accuracy in silt-dominated environments. These results suggest that wave-induced shear stress should be considered in sediment transport models for wave-dominated coastal aquaculture environments like southeast Tasmania.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104780"},"PeriodicalIF":4.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel piece-wise linear system for Floating Offshore Wind Turbines (FOWTs) wet-towing operations","authors":"Alicia Terrero-Gonzalez ,&nbsp;Saishuai Dai ,&nbsp;Richard D. Neilson ,&nbsp;Jim Papadopoulos ,&nbsp;Marcin Kapitaniak","doi":"10.1016/j.apor.2025.104764","DOIUrl":"10.1016/j.apor.2025.104764","url":null,"abstract":"<div><div>This paper evaluates the dynamic effects of a novel piece-wise linear towing system on the T-Omega Wind Floating Offshore Wind Turbine (FOWT), when connected between a tugboat and the wind turbine to perform wet-towing operations. The novel towing device consists on two rigid connectors that include an elastic coupling aiming to reduce variable connection forces transferred between the tug and the turbine, that could result into turbines’ undesired responses. Therefore, a numerical study of a 14 DOF towing system under regular sea waves is simulated with the state-of-art real multiphysics Marine Simulator at the National Decommissioning Centre (NDC) at the University of Aberdeen. The towing system performance is evaluated for <em>“Low”</em> to <em>“Moderate” Sea States</em> with a variation of wave parameters, such as, wave height (<span><math><mi>H</mi></math></span>), period (<span><math><mi>T</mi></math></span>) and incident angle (<span><math><mi>α</mi></math></span>). The effects on the FOWT dynamics are evaluated for different towing system parameters (i.e. coupling compliance, <span><math><msub><mrow><mi>χ</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>) and various constant towing velocities (<span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>). System trajectories are computed and RAOs are evaluated for the turbines’ heave, roll and pitch DOF, showing that the novel system effectively reduces the pitch RAOs up to a 36% for wave excitation periods close to the pitch resonance. Moreover, the coupling shifts the pitch resonance to higher periods, which vary proportionally with the system rigidity and the wave height. The effects on turbine’s heave and pitch hydrodynamics when wet-towed at velocities lower than 2.5 [m/s] can be neglected for head seas. Finally, the towing device relative displacements are evaluated as a function of the forces applied to choose most optimal device compliance for <em>“Low” Sea States</em>. The study reveals some nonlinear effects induced on the turbine, such as towing “Fishtailing”, and discloses the strong nonlinear turbine dynamics induced by towing and environmental parameters.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"164 ","pages":"Article 104764"},"PeriodicalIF":4.4,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}