Ocean Engineering最新文献

英文中文

Numerical modelling and analysis of tendon failures in nets of semi-submersible fish cages

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-28 DOI: 10.1016/j.oceaneng.2025.120768

Xueliang Wen , Christos Sakaris , Rune Schlanbusch , Muk Chen Ong

The growth of open-sea aquaculture has led to the development of advanced semi-submersible fish cages, such as Ocean Farm 1, Havfarm, and Shenlan 1. However, the net system is vulnerable to damage under rough sea conditions in open waters and requires continuous monitoring via load sensors. This study numerically investigates tendon failures in nets and the corresponding structural responses of a semi-submersible fish cage. The numerical method integrates a rigid body dynamics (RBD) model for simulating hull motions and a modified extended position-based dynamics (XPBD) method for modelling the deformations of mooring lines and nets connected to the hull. Hydrodynamic forces on the hull are calculated using a potential theory, while the Morison model is applied to evaluate drag forces on mooring lines and slender hull structures. The screen model is employed to compute hydrodynamic forces acting on the nets. Validation against experimental results confirms the accuracy of the method in predicting the natural periods of the fish cage. Results show that the mean tension in a broken tendon decreases significantly, by at least 38%. A strong correlation between the mean tension and the height of the breaking point is identified across various tendons and sea conditions. A tendon failure detection method is proposed to locate the broken tendon and determine the height of the breaking point. Additionally, the study captures the rapid tearing of nets following the rupture of a pre-tensioned tendon, resulting in a 5 m² hole within 0.12 s. These numerical results provide critical insights into monitoring and maintaining the net systems of semi-submersible fish cages and advance offshore aquaculture engineering.

{"title":"Numerical modelling and analysis of tendon failures in nets of semi-submersible fish cages","authors":"Xueliang Wen , Christos Sakaris , Rune Schlanbusch , Muk Chen Ong","doi":"10.1016/j.oceaneng.2025.120768","DOIUrl":"10.1016/j.oceaneng.2025.120768","url":null,"abstract":"<div><div>The growth of open-sea aquaculture has led to the development of advanced semi-submersible fish cages, such as Ocean Farm 1, Havfarm, and Shenlan 1. However, the net system is vulnerable to damage under rough sea conditions in open waters and requires continuous monitoring via load sensors. This study numerically investigates tendon failures in nets and the corresponding structural responses of a semi-submersible fish cage. The numerical method integrates a rigid body dynamics (RBD) model for simulating hull motions and a modified extended position-based dynamics (XPBD) method for modelling the deformations of mooring lines and nets connected to the hull. Hydrodynamic forces on the hull are calculated using a potential theory, while the Morison model is applied to evaluate drag forces on mooring lines and slender hull structures. The screen model is employed to compute hydrodynamic forces acting on the nets. Validation against experimental results confirms the accuracy of the method in predicting the natural periods of the fish cage. Results show that the mean tension in a broken tendon decreases significantly, by at least 38%. A strong correlation between the mean tension and the height of the breaking point is identified across various tendons and sea conditions. A tendon failure detection method is proposed to locate the broken tendon and determine the height of the breaking point. Additionally, the study captures the rapid tearing of nets following the rupture of a pre-tensioned tendon, resulting in a 5 m<sup>2</sup> hole within 0.12 s. These numerical results provide critical insights into monitoring and maintaining the net systems of semi-submersible fish cages and advance offshore aquaculture engineering.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"325 ","pages":"Article 120768"},"PeriodicalIF":4.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511775","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}

引用次数: 0

Effects of cracked semi-infinite ice sheets on the wave excited motion of a body floating on water

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-28 DOI: 10.1016/j.oceaneng.2025.120769

MoHan Zhang , RunShan Xiao , Zhen Xue , FaJun Yu

This study investigates the hydrodynamics of a floating body near cracked semi-infinite ice sheets under wave action, addressing two configurations: an ice channel (Model 1) and a single cracked ice sheet adjacent to open water (Model 2). By combining eigenfunction expansions with Green's identity under linear wave theory and Kirchhoff-Love plate assumptions, we solve the coupled wave-ice-body interaction problem through multi-subdomain matching. The results reveal that crack locations and ice thickness critically govern resonance phenomena. Key findings include: (1) Crack-induced wave reflections generate distinct oscillation patterns—U-shaped in Model 1 and Z-shaped in Model 2—with peak forces amplified at critical wavenumbers; (2) Increased crack distance enhances oscillation amplitudes, and cracks in the ice sheet prevents the amplitude of the wave-induced excitation forces from increasing with the wave number. Notably, cracks elevate heave motions by 30–50% compared to intact ice, crucial for polar vessel design. This work establishes predictive relationships between ice defects, hydrodynamic coefficients, and body responses, providing actionable insights for optimizing Arctic engineering structures in fractured ice environments.

{"title":"Effects of cracked semi-infinite ice sheets on the wave excited motion of a body floating on water","authors":"MoHan Zhang , RunShan Xiao , Zhen Xue , FaJun Yu","doi":"10.1016/j.oceaneng.2025.120769","DOIUrl":"10.1016/j.oceaneng.2025.120769","url":null,"abstract":"<div><div>This study investigates the hydrodynamics of a floating body near cracked semi-infinite ice sheets under wave action, addressing two configurations: an ice channel (Model 1) and a single cracked ice sheet adjacent to open water (Model 2). By combining eigenfunction expansions with Green's identity under linear wave theory and Kirchhoff-Love plate assumptions, we solve the coupled wave-ice-body interaction problem through multi-subdomain matching. The results reveal that crack locations and ice thickness critically govern resonance phenomena. Key findings include: (1) Crack-induced wave reflections generate distinct oscillation patterns—U-shaped in Model 1 and Z-shaped in Model 2—with peak forces amplified at critical wavenumbers; (2) Increased crack distance enhances oscillation amplitudes, and cracks in the ice sheet prevents the amplitude of the wave-induced excitation forces from increasing with the wave number. Notably, cracks elevate heave motions by 30–50% compared to intact ice, crucial for polar vessel design. This work establishes predictive relationships between ice defects, hydrodynamic coefficients, and body responses, providing actionable insights for optimizing Arctic engineering structures in fractured ice environments.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"325 ","pages":"Article 120769"},"PeriodicalIF":4.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519883","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}

引用次数: 0

An adaptive real-time ship roll motion prediction scheme based on two-stage multi-resolution decomposition

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-28 DOI: 10.1016/j.oceaneng.2025.120741

Jianchuan Yin , Nini Wang , Yaqing Shu

Real-time prediction of ship roll motion is crucial for enhancing marine safety and efficiency. To address the complex characteristics of ship roll dynamics, including nonlinearity, time-varying dynamics, and uncertainty induced by environmental disturbances and sailing conditions, an adaptive real-time ship roll neural prediction scheme is proposed based on a two-stage decomposition framework integrating empirical mode decomposition (EMD) and discrete wavelet transformation (DWT). The multi-resolution decomposition capabilities of EMD and DWT are combined with variable neural networks to achieve robust prediction performance. The decomposition order and the prediction model input order are adaptively determined based on EMD and Lipschitz quotients methods, respectively. The adaptability of the neural prediction scheme is enhanced with the network dimension, hidden units’ locations, and connecting parameters being real-time adjusted in a sequential learning mode. The two-stage EMD-DWT transformation and the parallel neural prediction strategies ensure the accuracy and stability of the prediction, and the sequential learning strategy of sliding data window enables fast processing speed and adaptability to time-varying dynamics. The feasibility and effectiveness of the proposed ship roll prediction scheme are validated through simulations based on the measured data of the real ship trial.

{"title":"An adaptive real-time ship roll motion prediction scheme based on two-stage multi-resolution decomposition","authors":"Jianchuan Yin , Nini Wang , Yaqing Shu","doi":"10.1016/j.oceaneng.2025.120741","DOIUrl":"10.1016/j.oceaneng.2025.120741","url":null,"abstract":"<div><div>Real-time prediction of ship roll motion is crucial for enhancing marine safety and efficiency. To address the complex characteristics of ship roll dynamics, including nonlinearity, time-varying dynamics, and uncertainty induced by environmental disturbances and sailing conditions, an adaptive real-time ship roll neural prediction scheme is proposed based on a two-stage decomposition framework integrating empirical mode decomposition (EMD) and discrete wavelet transformation (DWT). The multi-resolution decomposition capabilities of EMD and DWT are combined with variable neural networks to achieve robust prediction performance. The decomposition order and the prediction model input order are adaptively determined based on EMD and Lipschitz quotients methods, respectively. The adaptability of the neural prediction scheme is enhanced with the network dimension, hidden units’ locations, and connecting parameters being real-time adjusted in a sequential learning mode. The two-stage EMD-DWT transformation and the parallel neural prediction strategies ensure the accuracy and stability of the prediction, and the sequential learning strategy of sliding data window enables fast processing speed and adaptability to time-varying dynamics. The feasibility and effectiveness of the proposed ship roll prediction scheme are validated through simulations based on the measured data of the real ship trial.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"325 ","pages":"Article 120741"},"PeriodicalIF":4.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519887","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}

引用次数: 0

Stereo reconstruction of the free surface of breaking bow waves in a towing tank for DTMB 5415 model

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.oceaneng.2025.120764

Qian Wang, Haocheng Lu, Wenhao Tang, Jianyong He, Hua Liu

This study utilizes a binocular reconstruction system in a towing tank to conduct stereoscopic measurements of the breaking free surface of the quasi-steady bow wave of the DTMB 5415 model. It presents a detailed description of the application of binocular stereo technology in towing tank experiments, specifically focusing on how to enhance image features of the water surface texture, mitigate the impact of towing carriage vibrations, and achieve high-resolution reconstruction of the breaking wave surface. Experimental data show excellent agreement with standard reference results obtained from point measurements using a wave height sensor. An uncertainty analysis method for the binocular system measurements is proposed, addressing the issue of quantitatively evaluating errors in breaking wave surface measurements. The results present contour plots of wave elevation, velocity, and energy fields for the bow wave under different Froude numbers. Comparison with classical bow wave phenomena confirms that the wave surface elevation fields in both the disturbed and breaking regions can be reconstructed using the binocular system. At high speeds, the strong nonlinearity and breaking of the bow wave cause the magnitude of the velocity vector in the breaking region to exceed the forward speed of the ship model. The energy attenuation patterns along the wave crest differ for bow waves with varying degrees of breaking. This study provides reliable measurement techniques and direct data references for research on bow wave breaking.

{"title":"Stereo reconstruction of the free surface of breaking bow waves in a towing tank for DTMB 5415 model","authors":"Qian Wang, Haocheng Lu, Wenhao Tang, Jianyong He, Hua Liu","doi":"10.1016/j.oceaneng.2025.120764","DOIUrl":"10.1016/j.oceaneng.2025.120764","url":null,"abstract":"<div><div>This study utilizes a binocular reconstruction system in a towing tank to conduct stereoscopic measurements of the breaking free surface of the quasi-steady bow wave of the DTMB 5415 model. It presents a detailed description of the application of binocular stereo technology in towing tank experiments, specifically focusing on how to enhance image features of the water surface texture, mitigate the impact of towing carriage vibrations, and achieve high-resolution reconstruction of the breaking wave surface. Experimental data show excellent agreement with standard reference results obtained from point measurements using a wave height sensor. An uncertainty analysis method for the binocular system measurements is proposed, addressing the issue of quantitatively evaluating errors in breaking wave surface measurements. The results present contour plots of wave elevation, velocity, and energy fields for the bow wave under different Froude numbers. Comparison with classical bow wave phenomena confirms that the wave surface elevation fields in both the disturbed and breaking regions can be reconstructed using the binocular system. At high speeds, the strong nonlinearity and breaking of the bow wave cause the magnitude of the velocity vector in the breaking region to exceed the forward speed of the ship model. The energy attenuation patterns along the wave crest differ for bow waves with varying degrees of breaking. This study provides reliable measurement techniques and direct data references for research on bow wave breaking.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"324 ","pages":"Article 120764"},"PeriodicalIF":4.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509055","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}

引用次数: 0

Design of pump-jet propulsor based on data-driven optimization method

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.oceaneng.2025.120626

Xiaozuo Liu, Xinjing Wang, Ruixuan He, Huachao Dong, Ze Zhang, Peng Wang

This study optimizes the hydrodynamic performance of a pump-jet propulsor using a novel surrogate-assisted evolutionary algorithm. Incorporating Piecewise Cubic Hermite Interpolating Polynomials (PCHIP) for blade parameterization, a comprehensive parameterization methodology is developed. This approach establishes the propulsor's geometry while significantly expanding the design space, facilitating the generation of smooth and diverse geometric models. Besides, integrating the duct, rotor, stator, and hub, it efficiently establishes the entire models with 23 variables. Key design variables of rotor and stator include the distribution of pitch, camber, thickness, skew and mounting angle, besides attack angle of duct and hub as well as the distance between rotor disc and stator disc are also involved. The optimization process seeks to maximize efficiency while considering thrust, torque, and minimum pressure requirements through one objective and three constraint functions. This approach not only enhances optimization efficiency but also prevents unrealistic design outcomes. As a result, the efficiency improves by 7.67% compared to the initial design. The optimized model changes the distribution of the rotor pitch ratio at higher radius (especially over 0.75 r/R), drops the duct's angle of attack by about 1°, and forms a gentler pressure distribution that decreases the risk of flow separation. These adjustments lead to improved thrust stability and better coordination among component groups, making the system more efficient and well-integrated. Further unsteady analysis revealed enhanced hydrodynamic performance. With minimal designer intervention, this data-driven optimization method effectively fine-tunes each component of the pump-jet, enhancing overall system performance.

{"title":"Design of pump-jet propulsor based on data-driven optimization method","authors":"Xiaozuo Liu, Xinjing Wang, Ruixuan He, Huachao Dong, Ze Zhang, Peng Wang","doi":"10.1016/j.oceaneng.2025.120626","DOIUrl":"10.1016/j.oceaneng.2025.120626","url":null,"abstract":"<div><div>This study optimizes the hydrodynamic performance of a pump-jet propulsor using a novel surrogate-assisted evolutionary algorithm. Incorporating Piecewise Cubic Hermite Interpolating Polynomials (PCHIP) for blade parameterization, a comprehensive parameterization methodology is developed. This approach establishes the propulsor's geometry while significantly expanding the design space, facilitating the generation of smooth and diverse geometric models. Besides, integrating the duct, rotor, stator, and hub, it efficiently establishes the entire models with 23 variables. Key design variables of rotor and stator include the distribution of pitch, camber, thickness, skew and mounting angle, besides attack angle of duct and hub as well as the distance between rotor disc and stator disc are also involved. The optimization process seeks to maximize efficiency while considering thrust, torque, and minimum pressure requirements through one objective and three constraint functions. This approach not only enhances optimization efficiency but also prevents unrealistic design outcomes. As a result, the efficiency improves by 7.67% compared to the initial design. The optimized model changes the distribution of the rotor pitch ratio at higher radius (especially over 0.75 r/R), drops the duct's angle of attack by about 1°, and forms a gentler pressure distribution that decreases the risk of flow separation. These adjustments lead to improved thrust stability and better coordination among component groups, making the system more efficient and well-integrated. Further unsteady analysis revealed enhanced hydrodynamic performance. With minimal designer intervention, this data-driven optimization method effectively fine-tunes each component of the pump-jet, enhancing overall system performance.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"325 ","pages":"Article 120626"},"PeriodicalIF":4.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511770","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}

引用次数: 0

Numerical analysis of mooring systems for reducing peak mooring line tensions in a combined wind and wave energy system at an intermediate water depth

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.oceaneng.2025.120767

Chern Fong Lee, Muk Chen Ong

Mooring systems for floating marine renewable energy (MRE) platforms in intermediate water depths (50–100 m) experience high mooring line tension spikes due to the short mooring line lengths. To address this challenge, a novel mooring system, the “soft-chain,” is proposed for a combined wind and wave energy system at a 50 m water depth. By integrating chain-catenary and semi-taut mooring features, the “soft-chain” system reduces peak mooring line tensions during extreme weather while maintaining acceptable platform offsets. The feasibility of the “soft-chain” system for the Semi-submersible Torus Flap Combination (STFC) concept is evaluated alongside two other mooring systems: a chain-catenary (“chain-cat”) system and a polyester-based “semi-taut” system. Performance metrics include maximum and minimum mooring line tensions, horizontal offsets, vertical anchor loads, and the occurrences of tension loss. Results show that the “soft-chain” system reduces the maximum windward mooring line tension by 64% compared to “chain-cat” and 10% compared to “semi-taut” systems. Moreover, the maximum vertical anchor force in the “soft-chain” system is 14% lower than in “semi-taut” but 23% higher than in “chain-cat.” Two alternative configurations, the “soft-chain-Alt1” and “soft-chain-Alt2” systems, result in further reductions in peak tension by 5.3% and 12.5%, respectively, providing insights for further performance optimization.

{"title":"Numerical analysis of mooring systems for reducing peak mooring line tensions in a combined wind and wave energy system at an intermediate water depth","authors":"Chern Fong Lee, Muk Chen Ong","doi":"10.1016/j.oceaneng.2025.120767","DOIUrl":"10.1016/j.oceaneng.2025.120767","url":null,"abstract":"<div><div>Mooring systems for floating marine renewable energy (MRE) platforms in intermediate water depths (50–100 m) experience high mooring line tension spikes due to the short mooring line lengths. To address this challenge, a novel mooring system, the “soft-chain,” is proposed for a combined wind and wave energy system at a 50 m water depth. By integrating chain-catenary and semi-taut mooring features, the “soft-chain” system reduces peak mooring line tensions during extreme weather while maintaining acceptable platform offsets. The feasibility of the “soft-chain” system for the Semi-submersible Torus Flap Combination (STFC) concept is evaluated alongside two other mooring systems: a chain-catenary (“chain-cat”) system and a polyester-based “semi-taut” system. Performance metrics include maximum and minimum mooring line tensions, horizontal offsets, vertical anchor loads, and the occurrences of tension loss. Results show that the “soft-chain” system reduces the maximum windward mooring line tension by 64% compared to “chain-cat” and 10% compared to “semi-taut” systems. Moreover, the maximum vertical anchor force in the “soft-chain” system is 14% lower than in “semi-taut” but 23% higher than in “chain-cat.” Two alternative configurations, the “soft-chain-Alt1” and “soft-chain-Alt2” systems, result in further reductions in peak tension by 5.3% and 12.5%, respectively, providing insights for further performance optimization.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"325 ","pages":"Article 120767"},"PeriodicalIF":4.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509996","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}

引用次数: 0

Berth allocation and tugboat scheduling problem for tidal ports with compound channels: The case of Tianjin port

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.oceaneng.2025.120744

Hao Fan , Tian-Hui Zhang , Jian Zhao , Li-Jun Yue

Due to the water depth limitations of the channel, large vessels need to enter and exit tidal ports by the tide, especially the tidal port with compound channels that have two-way navigable, and large and small vessels are divided, which puts forward higher requirements for berth allocation and tugboat scheduling of the tidal port. To address the needs of numerous vessels entering and leaving the port through such compound channels, port operators must allocate berths and schedule tugboats to assist with berthing, shifting, and unberthing operations to ensure the safety of the vessels. For berth allocation and tugboat scheduling in tidal ports, we first apply regression analysis to derive a function representing tidal variations over time. Subsequently, we propose a two-stage mixed-integer linear programming model. The first stage focuses on minimizing costs related to berth allocation, while the second stage addresses tugboat scheduling. The model is solved using enumeration and heuristic algorithms. The results prove the joint optimization of berth allocation and tugboat scheduling not only effectively saves the port operating cost, but also reduces fuel consumption from vessels and tugboats.

{"title":"Berth allocation and tugboat scheduling problem for tidal ports with compound channels: The case of Tianjin port","authors":"Hao Fan , Tian-Hui Zhang , Jian Zhao , Li-Jun Yue","doi":"10.1016/j.oceaneng.2025.120744","DOIUrl":"10.1016/j.oceaneng.2025.120744","url":null,"abstract":"<div><div>Due to the water depth limitations of the channel, large vessels need to enter and exit tidal ports by the tide, especially the tidal port with compound channels that have two-way navigable, and large and small vessels are divided, which puts forward higher requirements for berth allocation and tugboat scheduling of the tidal port. To address the needs of numerous vessels entering and leaving the port through such compound channels, port operators must allocate berths and schedule tugboats to assist with berthing, shifting, and unberthing operations to ensure the safety of the vessels. For berth allocation and tugboat scheduling in tidal ports, we first apply regression analysis to derive a function representing tidal variations over time. Subsequently, we propose a two-stage mixed-integer linear programming model. The first stage focuses on minimizing costs related to berth allocation, while the second stage addresses tugboat scheduling. The model is solved using enumeration and heuristic algorithms. The results prove the joint optimization of berth allocation and tugboat scheduling not only effectively saves the port operating cost, but also reduces fuel consumption from vessels and tugboats.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"324 ","pages":"Article 120744"},"PeriodicalIF":4.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509056","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}

引用次数: 0

The suggestion of a practical methodology for determining the optimum position of the flow control fin on a ship

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.oceaneng.2025.120763

Min-jeong Won , Gi-su Song

In this study, the advanced methodology for finding the optimal position of the flow control fin (FCF) on a hull was proposed. The traditional method for the FCF design required the designer's empirical knowledge and a lot of computational time and cost for the verification of performance on FCF. To suggest the alternative, firstly, the numerical simulation results of the bare hull was analyzed to find the optimal position of the FCF. In this study, two types of FCF were proposed for two different objectives, which are the resistance reduction and wake quality improvement. Especially the flow angle around hull and pressure distribution on a hull surface give us an important clue for this study. By applying the proposed methodology on various ship types such as tankers and containers, it is verified that it would be inductively applicable to the FCF design process.

引用次数: 0

A Python-based integrated time domain analysis method for floating wind turbines

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.oceaneng.2025.120782

Li Dong , Zhidong Wang , Zhongyao Fan , Yidi Shui , Wenxi Shao , Zhengshun Cheng , Peng Chen

Integrated analysis and design optimization of floating wind turbines (FWT) is vital for cost reduction and efficiency enhancement. However, existing simulation software faces scalability and efficiency limitations in early design phases and multi-objective optimization. To address these challenges, this study develops a Python-based integrated time-domain simulation method for FWT, named Pywind. The aerodynamic module leverages blade element momentum (BEM) theory with corrections, including dynamic stall, for accuracy under high wind speeds. The hydrodynamic module uses potential flow theory and incorporates viscous effects via Morison's equation. The structural and dynamic modeling employs the Newton-Euler method for single rigid-body dynamics, providing a streamlined yet robust representation of system behavior with high computational efficiency. The mooring system combines a quasi-static catenary approach with a lumped mass method, while the control module supports variable rotor speed and pitch control for constant torque and power output. Verification was conducted using OpenFAST across various aspects, such as system dynamics, external load calculations, and structural responses. The results exhibited strong agreement with OpenFAST, with discrepancies in mean values remaining within 2%. This Python-based implementation offers significant potential for advancing industrial design and optimization of FWT while supporting innovative multi-physics simulation and AI-driven research in academia.

{"title":"A Python-based integrated time domain analysis method for floating wind turbines","authors":"Li Dong , Zhidong Wang , Zhongyao Fan , Yidi Shui , Wenxi Shao , Zhengshun Cheng , Peng Chen","doi":"10.1016/j.oceaneng.2025.120782","DOIUrl":"10.1016/j.oceaneng.2025.120782","url":null,"abstract":"<div><div>Integrated analysis and design optimization of floating wind turbines (FWT) is vital for cost reduction and efficiency enhancement. However, existing simulation software faces scalability and efficiency limitations in early design phases and multi-objective optimization. To address these challenges, this study develops a Python-based integrated time-domain simulation method for FWT, named Pywind. The aerodynamic module leverages blade element momentum (BEM) theory with corrections, including dynamic stall, for accuracy under high wind speeds. The hydrodynamic module uses potential flow theory and incorporates viscous effects via Morison's equation. The structural and dynamic modeling employs the Newton-Euler method for single rigid-body dynamics, providing a streamlined yet robust representation of system behavior with high computational efficiency. The mooring system combines a quasi-static catenary approach with a lumped mass method, while the control module supports variable rotor speed and pitch control for constant torque and power output. Verification was conducted using OpenFAST across various aspects, such as system dynamics, external load calculations, and structural responses. The results exhibited strong agreement with OpenFAST, with discrepancies in mean values remaining within 2%. This Python-based implementation offers significant potential for advancing industrial design and optimization of FWT while supporting innovative multi-physics simulation and AI-driven research in academia.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"324 ","pages":"Article 120782"},"PeriodicalIF":4.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509058","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}

引用次数: 0

A graph attention network-based learning framework for automatic detection of abnormal vessel behaviors

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.oceaneng.2025.120700

Maohan Liang , Yuanzhe Zhang , Qiqiang Jin , Ryan Wen Liu

With the rapid expansion of maritime activities, the need to detect abnormal vessel behaviors using advanced data-driven methods has become increasingly critical for ensuring maritime safety and efficiency. Existing approaches often overlook the temporal dependencies and feature correlations in vessel behaviors. This limitation reduces their ability to capture the complexities of maritime operations. To address these challenges, we propose GAT-AD, a novel graph attention network-based framework for anomaly detection in vessel behavior. Our framework incorporates three key components: (1) a graph attention module that combines temporal and feature attention to capture sequential and feature dependencies, (2) an embedding layer to extract latent information from vessel data, enhancing representation learning, and (3) a joint detection module that calculates anomaly scores using both reconstruction-based and prediction-based techniques. We validate the effectiveness of GAT-AD through extensive experiments using real-world AIS data. Ablation studies highlight the contributions of individual components, while comparative experiments confirm that GAT-AD outperforms state-of-the-art baselines. Additionally, case studies highlight the framework’s ability to detect and explain different types of anomalies, further underscoring its practical applicability in real-world maritime scenarios.

{"title":"A graph attention network-based learning framework for automatic detection of abnormal vessel behaviors","authors":"Maohan Liang , Yuanzhe Zhang , Qiqiang Jin , Ryan Wen Liu","doi":"10.1016/j.oceaneng.2025.120700","DOIUrl":"10.1016/j.oceaneng.2025.120700","url":null,"abstract":"<div><div>With the rapid expansion of maritime activities, the need to detect abnormal vessel behaviors using advanced data-driven methods has become increasingly critical for ensuring maritime safety and efficiency. Existing approaches often overlook the temporal dependencies and feature correlations in vessel behaviors. This limitation reduces their ability to capture the complexities of maritime operations. To address these challenges, we propose GAT-AD, a novel graph attention network-based framework for anomaly detection in vessel behavior. Our framework incorporates three key components: (1) a graph attention module that combines temporal and feature attention to capture sequential and feature dependencies, (2) an embedding layer to extract latent information from vessel data, enhancing representation learning, and (3) a joint detection module that calculates anomaly scores using both reconstruction-based and prediction-based techniques. We validate the effectiveness of GAT-AD through extensive experiments using real-world AIS data. Ablation studies highlight the contributions of individual components, while comparative experiments confirm that GAT-AD outperforms state-of-the-art baselines. Additionally, case studies highlight the framework’s ability to detect and explain different types of anomalies, further underscoring its practical applicability in real-world maritime scenarios.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"325 ","pages":"Article 120700"},"PeriodicalIF":4.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509994","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}

引用次数: 0

首页上一页

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

Ocean Engineering

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀