Applied Ocean Research最新文献

{"title":"Control co-design for wave energy systems","authors":"John V. Ringwood","doi":"10.1016/j.apor.2025.104514","DOIUrl":"10.1016/j.apor.2025.104514","url":null,"abstract":"<div><div>Control co-design (CCD) has become a powerful paradigm in the total optimisation of the dynamics of a system against a defined performance goal. Given the impact of control on wave energy systems, including significant effects on motion and energy capture performance, it is imperative that controller and system are optimised together to maximise (economic) system performance. There are a number of design aspects that can usefully be addressed by CCD in wave energy systems, including device geometry, mooring configuration, power take-off (PTO) parameters, and array layout. A number of these design aspects present significant computational challenges and, as a result, wave energy CCD studies typically address a single design aspect at a time. This paper examines the useful roles that CCD can play in wave energy systems, important criteria to consider, and the potential interaction between individual wave energy CCD aspects.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104514"},"PeriodicalIF":4.3,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis and experimental research on the coupled motion of the foot and paddle of crab-like robot based on biological observation","authors":"Shihao Hu ,&nbsp;Mingfei Xin ,&nbsp;Siqi Li ,&nbsp;Jiawei Li ,&nbsp;Gang Wang ,&nbsp;Shuo Zhang ,&nbsp;Xi Chen","doi":"10.1016/j.apor.2025.104524","DOIUrl":"10.1016/j.apor.2025.104524","url":null,"abstract":"<div><div>Shallow water regions, characterized by complex and varied terrain as well as dense aquatic vegetation, pose challenges for traditional propeller-based propulsion systems, which can damage seabed substrates and become entangled with aquatic plants. Amphibious bionic robots, with their remarkable environmental adaptability, have emerged as a research focus for operations in shoal environments. Drawing inspiration from the walking behavior of Portunus trituberculatus (Portunus), this paper presents a walking method for a crab-like robot that incorporates a coupled foot-paddle motion. Using the direct linear transformation (DLT) algorithm, we have captured the motion trajectories of the swimming paddles (in both heart-shaped and figure-eight patterns) during the underwater locomotion of Portunus. A hydrodynamic simulation environment was established, and the robot model was simplified. Based on the simulation results, we analyzed the influence of coupled foot-paddle motion on the robot’s force distribution from three perspectives: pressure distribution maps of the swimming paddles, force curves, and vortex diagrams. Experimental validation confirmed the effectiveness of the coupled foot-paddle motion strategy in enhancing underwater walking speed, with the figure-eight flapping mode achieving an average speed increase of 11.5% and the heart-shaped flapping mode achieving an average speed increase of 9.8%. Furthermore, in terms of stability, the coupled foot-paddle motion with heart-shaped flapping exhibited superior performance.The experimental results verify the effectiveness of the foot-paddle coupled motion strategy proposed in this paper, which provides a research basis for bionic robot composite propulsion research.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104524"},"PeriodicalIF":4.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DCNet: A data-driven framework for DVL calibration","authors":"Zeev Yampolsky,&nbsp;Itzik Klein","doi":"10.1016/j.apor.2025.104525","DOIUrl":"10.1016/j.apor.2025.104525","url":null,"abstract":"<div><div>Autonomous underwater vehicles (AUVs) are underwater robotic platforms used in a variety of applications. An AUV’s navigation solution relies heavily on the fusion of inertial sensors and Doppler velocity logs (DVL), where the latter delivers accurate velocity updates. To ensure accurate navigation, a DVL calibration is undertaken before the mission begins to estimate its error terms. During calibration, the AUV follows a complex trajectory and employs nonlinear estimation filters to estimate error terms. In this paper, we introduce DCNet, a data-driven framework that utilizes a two-dimensional convolution kernel in an innovative way. Using DCNet and our proposed DVL error model, we offer a rapid calibration procedure. This can be applied to a trajectory with a nearly constant velocity. To train and test our proposed approach a dataset of 276 min long with real DVL recorded measurements was used. We demonstrated an average improvement of 70% in accuracy and 80% improvement in calibration time, compared to the baseline approach, with a low-performance DVL. As a result of those improvements, an AUV employing a low-cost DVL, can achieve higher accuracy, shorter calibration time, and apply a simple nearly constant velocity calibration trajectory. Our results also open up new applications for marine robotics utilizing low-cost, high-accurate DVLs.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104525"},"PeriodicalIF":4.3,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wave heights over Canadian oceans: Tempo-spatial variations and climate-oscillation impacts based on macroscale spatially-extrapolative retrieval from altimetric ensembles","authors":"Cong Dong ,&nbsp;Gordon Huang ,&nbsp;Guanhui Cheng ,&nbsp;Yanpeng Cai","doi":"10.1016/j.apor.2025.104517","DOIUrl":"10.1016/j.apor.2025.104517","url":null,"abstract":"<div><div>Estimation and analyses of significant wave heights (SWHs) are crucial to climate research, ocean engineering and other applications, with satellite retrieval serving as a fundamental approach. However, few studies attempt to extrapolate SWH models across buoy grids to retrieve ungauged-grid SWHs from multiple altimeters at macroscales, or examine variations of extreme SWHs in relation to climate oscillations, particularly in the Canadian context. To fill these gaps, we develop a macroscale spatially-extrapolative ensemble wave-height retrieval and analysis (MEERA) method to retrieve SWHs from multi-mission satellite altimetry and reveal tempo-spatial characteristics of SWHs means and extremes as well as their variations with climate oscillations. The method is applied across all Canadian waters. According to modeling results, MEERA significantly enhances consistency and accuracy of retrieved SWHs (especially in coastal areas), e.g., reducing biases of conventional methods by over 98%. From 1985 to 2020, waves were strongly seasonal and regional, which drop from winter (1.45 m) to summer (1.17 m) and tend to decline northward. SWHs tend to decrease in mid-eastern regions (e.g., Hudson Bay, Davis Strait and Gulf of St Lawrence) and increase in Canadian Atlantic, Pacific, and Arctic. Across all Canadian waters, climate indices regarding precipitation, e.g., the NBRA (Northeast Brazil Rainfall Anomaly) index, pose the strongest impacts on extreme SWHs compared with others. In Pacific and Atlantic, spatial patterns of winter SWH extremes are associated with negative NAO (North Atlantic Oscillation). El Niño might increase SWHs extremes over the Pacific and Arctic, while decreasing them over mid-eastern regions. This study advances macroscale SWH estimation and analysis, enhancing the understanding of SWH characteristics and their variations across Canada under climate change.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104517"},"PeriodicalIF":4.3,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plastic optical fiber sensors for mooring lines monitoring in floating wind turbines: A reliability study of OTDR measurement","authors":"Romain Grangeat ,&nbsp;Marion Girard ,&nbsp;Cyril Lupi ,&nbsp;Dominique Leduc ,&nbsp;Frédéric Jacquemin","doi":"10.1016/j.apor.2025.104541","DOIUrl":"10.1016/j.apor.2025.104541","url":null,"abstract":"<div><div>This study investigates the use of POF (Plastic Optical Fibers) for mooring lines monitoring in floating wind turbines. Focusing on their mechanical adaptability and optical performance in marine environments. Optical attenuation measurement are employed to determine integrity of POFs under mechanical stresses such as tension and torsion, as well as during prolonged water immersion at ambient temperature. Key findings demonstrate a high deformation capacity of POFs (up to 70 % strain), with negligible loss in light transmission under mechanical stresses in tension and torsion. Additionally, water absorption was found to have a limited impact on optical attenuation, even after extended immersion. These results confirm the suitability in POFs for mooring lines monitoring in floating wind turbines. Furthermore, elongation measurements performed on POFs of up to 100 meters in length validated the feasibility of monitoring strain using both transmission and reflection OTDR (Optical Time Domain Reflectometer) measurement. The results highlight POFs as cost-effective, durable sensors capable of addressing the high-strain demands of mooring line applications.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104541"},"PeriodicalIF":4.3,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An improved direct forcing immersed boundary method for floating body simulations in waves","authors":"Ahmet Soydan,&nbsp;Widar W. Wang,&nbsp;Hans Bihs","doi":"10.1016/j.apor.2025.104523","DOIUrl":"10.1016/j.apor.2025.104523","url":null,"abstract":"<div><div>This paper introduces a novel direct forcing immersed boundary method tailored to simulate nonlinear interactions between ocean waves and arbitrarily complex free-floating structures. Within an open-source hydrodynamic framework, we couple the fluid–structure interaction (FSI) algorithm with the two-phase flow solver through forcing at the fluid–solid interface. We substantially enhance this coupling process by altering the density interpolation method, significantly reducing the interface smearing region, which improves both the stability and accuracy of the fluid flow in the vicinity of the floating objects. The tracking of the fluid–solid interface in the Eulerian domain is based on a level set function, thus avoiding the need for dynamically moving or overset meshes and greatly simplifying the mesh generation process. Rigid body dynamics are implemented using Euler parameters and Hamiltonian mechanics, allowing for arbitrarily large motions of the floating body. The presented approach is tested and validated with several 2D and 3D problems, including a full-scale simulation of a floating semi-submersible offshore wind turbine in waves. All numerical results demonstrate the accuracy and robustness of the new method, highlighting its potential as an outstanding alternative to existing numerical approaches for realistic floating-body simulations in waves.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104523"},"PeriodicalIF":4.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of thrust bearing parameters in shafting-shell coupling system from frequency response function with artificial neural networks","authors":"Cong Zhang ,&nbsp;Yaqi Tian ,&nbsp;Yifan Xie ,&nbsp;Lei Yang","doi":"10.1016/j.apor.2025.104528","DOIUrl":"10.1016/j.apor.2025.104528","url":null,"abstract":"<div><div>The thrust bearing is a critical component for power transmission and vibration coupling between the propulsion shafting and the shell of the underwater vehicle. Identifying thrust bearing parameters is crucial for studying the vibration and diagnosing bearing faults of the underwater vehicle. In this study, key information was extracted from the frequency response function (FRF) of the shafting-shell coupling system, and then the artificial neural network (ANN) was used to predict the stiffness and damping of the thrust bearing. The dataset used to train the ANN came from the analytical dynamic model of the shafting-shell system. This analytical approach offers high computational efficiency, making it feasible to generate a substantial amount of training data within a reasonable timeframe. In the analytical dynamic model, the shell was modeled using the Flügge theory, while the shafting system was modeled using the Euler-Bernoulli beam theory. The bearings were simplified as a spring-damping system to represent the connection between the shafting system and the shell. This study employed two ANN algorithms: Backpropagation Neural Network (BP) and Genetic Algorithm-optimized Backpropagation Neural Network (GABP). The results indicate that both BP and GABP effectively predict the stiffness and damping of thrust bearings. Moreover, GABP demonstrates more stable prediction results with smaller prediction errors. The proposed method for predicting thrust bearing parameters leverages features from the FRF to train the ANN, which provides good robustness, maintaining effective results even when the signal-to-noise ratio of the FRF is reduced. The thrust bearing parameter prediction model was validated through experiment, confirming the effectiveness of using ANNs to predict bearing parameters in shafting-shell coupling systems from FRF. This study realizes efficient prediction of bearing parameters, providing a reference for vibration reduction, operational state monitoring, and fault diagnosis of underwater vehicles.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104528"},"PeriodicalIF":4.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An evaluation method for pipeline corrosion risk index weighting in beach and sea oil fields based on combined weighting with improved hierarchical analysis and Bayesian networks","authors":"Wenbin Wang,&nbsp;Shibin Jiang,&nbsp;Jianguo Liu,&nbsp;Gan Cui","doi":"10.1016/j.apor.2025.104522","DOIUrl":"10.1016/j.apor.2025.104522","url":null,"abstract":"<div><div>Coastal oil and gas pipelines are prone to corrosion due to complex environmental factors, while traditional risk assessment methods often suffer from subjective bias and oversimplified, one-sided weighting strategies. To address these limitations, this study proposes a risk evaluation model based on game theory, combining an improved analytic hierarchy process (AHP) and a Bayesian network for composite weighting. First, a coastal pipeline corrosion leakage risk indicator system is constructed. Next, a gray relational analysis-improved AHP model is introduced for hierarchical weighting. A Bayesian network model is constructed using the T-S fuzzy fault tree, and probability weighting is performed through hierarchical importance analysis. Finally, based on game theory, the above two weightings are combined to calculate the composite weight. Additionally, to verify the model's applicability, a corrosion risk assessment for a coastal pipeline was conducted. The results indicated that the model could effectively mitigates the over-reliance on expert subjective judgment and fragmented analysis of risk factors in corrosion risk assessment for coastal oil and gas pipelines, Critical factors such as high sand content and external coating failure were identified as dominant risks, which were overlooked in conventional models. The evaluation results were generally consistent with the actual situation.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104522"},"PeriodicalIF":4.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of wave characteristics in the Northern Yellow sea based on field observations","authors":"Hongyuan Shi ,&nbsp;Huaiyuan Xue ,&nbsp;Longsheng Li ,&nbsp;Chao Zhan ,&nbsp;Zaijin You","doi":"10.1016/j.apor.2025.104527","DOIUrl":"10.1016/j.apor.2025.104527","url":null,"abstract":"<div><div>With the increasing frequency of extreme weather events driven by global climate change, a comprehensive analysis of wave characteristics under extreme meteorological conditions is essential for improving the safety of maritime transportation. Previous research has predominantly focused on wave characteristics during typhoons, while studies on wave characteristics under frequent cold wave climates in mid- to high-latitude regions are still lacking. In this study, we used half-year wave data (March to September 2023) for the Northern Yellow Sea. We conducted a statistical analysis of wave characteristic values in this sea area and investigated the relationship between various characteristic wave heights, the mean wave height, and the significant wave height. A detailed analysis of the wave height, wave period, and wave spectrum during a typical cold wave event in April was performed to describe the wave characteristics and their variations in this area under extreme meteorological conditions. The results showed that the wave height distribution in this region exhibited a Weibull distribution, which fitted better than the Rayleigh and Gumbel distributions, especially in cases with high wave heights. The distribution of the wave period diverged as the spectral width increased, and the Sunfu and Gumbel distributions achieved better fitting under wide-spectrum conditions. The joint distribution of the wave height and period exhibited an inclined triangular pattern; however, discrepancies remained when compared with theoretical models, particularly for large wave heights and extended periods. Additionally, during cold wave events, the wave characteristics in the region exhibited a double-peaked spectrum as a result of the interaction between low-frequency swells and high-frequency wind waves. Our research results provide a reference for maritime navigation safety in this sea area.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104527"},"PeriodicalIF":4.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fatigue damage assessment of steel catenary risers in the touchdown zone accounting for soil remoulding and reconsolidation effects","authors":"Hossein Janbazi,&nbsp;Hodjat Shiri","doi":"10.1016/j.apor.2025.104526","DOIUrl":"10.1016/j.apor.2025.104526","url":null,"abstract":"<div><div>The design of steel catenary risers (SCRs) is mainly affected by fatigue performance in the touchdown zone (TDZ), where the riser cyclically interacts with the seabed. This cyclic motion leads to seabed soil softening and remoulding. However, over an extended period of riser operations, the seabed soil undergoes a drainage because of small motion amplitudes of the floating vessel during calm weather or a limited contact with the seabed due to vessel relocation. This may cause recovery of the soil strength associated with excess pore pressure dissipation resulting in an extra fatigue damage accumulation in the TDZ. In the current study, a global SCR analysis has been conducted using a series of coded springs along the TDZ to model advanced SCR-seabed interactions. The instantaneous undrained shear strength of the soil is determined by using a recently developed effective stress framework. The effects of soil remolding and consolidation were integrated during both the dynamic motion of the SCR and intervening pause periods within the critical-state soil mechanics. The model updates the SCR-soil interaction spring at every time increment of dynamic analysis, calculating the cross-section stress range while taking into account the overall configuration of the riser on the seabed. The study showed that the consolidation may result in an increased fatigue damage of about 23 %, which is currently neglected by the existing non-linear SCR-soil interaction models.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104526"},"PeriodicalIF":4.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}