Ocean Engineering最新文献_第8页

Frequency-shifted array data: Improving beam resolution in underwater acoustic beamforming and enabling separation of pulse sources with the same azimuth 移频阵列数据：提高水声波束形成中的波束分辨率，实现相同方位的脉冲源分离

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-11 DOI: 10.1016/j.oceaneng.2026.124168

Changpeng Liu , Shihong Zhou , Yubo Qi , Shuanghu Liu , Shuai Chen

Affected by beam broadening and splitting, underwater acoustic high-resolution beamforming algorithms may struggle to achieve their theoretical beam resolution capability. Unlike the frequency-fixed (FF) array data used in traditional frequency-domain beamforming, this paper explores the application of frequency-shifted (FS) array data to enhance beam resolution. Frequency-shifted array data is generated through data selection along the element-frequency domain interference striations formed by array signals with different source ranges. This process is equivalent to enhancing the consistency of array signals, thereby avoiding beam broadening and splitting. Such a change at the data level enables the FS array signal processing method to be easily extended to other high-resolution algorithms (e.g., subspace-based algorithms, compressed sensing algorithms) while ensuring their theoretical beam resolution capability. In addition, by leveraging the differences in arrival times of pulse sources with the same azimuth but different positions, beamforming based on FS array data can create differences in beam positions, thereby achieving separation of sources with the same azimuth in the beam domain. The above research content is verified through experimental data and simulation data in shallow-water and deep-water scenarios.

受波束展宽和劈裂的影响，水声高分辨率波束形成算法可能难以达到其理论波束分辨率。与传统频域波束形成中使用的固定频率（FF）阵列数据不同，本文探索了利用移频（FS）阵列数据来提高波束分辨率。移频阵列数据是沿着不同源距离的阵列信号形成的元频域干扰条纹进行数据选择而产生的。这一过程相当于增强了阵列信号的一致性，从而避免了波束的展宽和分裂。数据级的这种变化使得FS阵列信号处理方法可以很容易地扩展到其他高分辨率算法（例如，基于子空间的算法，压缩感知算法），同时保证其理论波束分辨率能力。此外，利用相同方位角不同位置的脉冲源到达时间的差异，基于FS阵列数据的波束形成可以产生波束位置的差异，从而实现波束域相同方位角的源分离。通过浅水和深水场景的实验数据和模拟数据对上述研究内容进行了验证。

{"title":"Frequency-shifted array data: Improving beam resolution in underwater acoustic beamforming and enabling separation of pulse sources with the same azimuth","authors":"Changpeng Liu , Shihong Zhou , Yubo Qi , Shuanghu Liu , Shuai Chen","doi":"10.1016/j.oceaneng.2026.124168","DOIUrl":"10.1016/j.oceaneng.2026.124168","url":null,"abstract":"<div><div>Affected by beam broadening and splitting, underwater acoustic high-resolution beamforming algorithms may struggle to achieve their theoretical beam resolution capability. Unlike the frequency-fixed (FF) array data used in traditional frequency-domain beamforming, this paper explores the application of frequency-shifted (FS) array data to enhance beam resolution. Frequency-shifted array data is generated through data selection along the element-frequency domain interference striations formed by array signals with different source ranges. This process is equivalent to enhancing the consistency of array signals, thereby avoiding beam broadening and splitting. Such a change at the data level enables the FS array signal processing method to be easily extended to other high-resolution algorithms (e.g., subspace-based algorithms, compressed sensing algorithms) while ensuring their theoretical beam resolution capability. In addition, by leveraging the differences in arrival times of pulse sources with the same azimuth but different positions, beamforming based on FS array data can create differences in beam positions, thereby achieving separation of sources with the same azimuth in the beam domain. The above research content is verified through experimental data and simulation data in shallow-water and deep-water scenarios.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"350 ","pages":"Article 124168"},"PeriodicalIF":5.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947759","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

AUV single-beacon localization based on virtual long baseline with an isogradient sound velocity profile 基于等梯度声速剖面虚拟长基线的水下航行器单信标定位

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-11 DOI: 10.1016/j.oceaneng.2026.124169

Xiang Yu , Zhang Shi , Hongde Qin , Peilong Xu

Under the influence of factors such as temperature, salinity, and water depth, the underwater acoustic propagation channel exhibits pronounced stratification, which in turn affects the performance of autonomous underwater vehicle (AUV) single-beacon localization systems. This study investigates the impact of acoustic stratification and focuses specifically on the AUV single-beacon localization method under an isogradient sound velocity profile (SVP) condition. By leveraging the relationship between acoustic signal transit time and horizontal range under an isogradient SVP, a virtual long baseline localization model is constructed using dead reckoning data from the AUV. Subsequently, two distinct position estimation methods are proposed: a closed-form solution based on two-step weighted least squares, and a semi-definite programming (SDP) solution obtained through semi-definite relaxation technique. Numerical simulations and semi-physical experiments demonstrate that by accounting for the stratification of the underwater acoustic channel, both the proposed closed-form and SDP-based solutions achieve enhanced positioning accuracy. The closed-form solution provides higher computational efficiency, whereas the SDP approach achieves superior localization performance–particularly when the number of virtual beacons is limited or measurement noise is substantial.

在温度、盐度和水深等因素的影响下，水声传播通道呈现明显的分层现象，进而影响自主水下航行器单信标定位系统的性能。本文研究了声分层的影响，重点研究了等梯度声速剖面（SVP）条件下AUV单信标定位方法。利用等梯度SVP下声信号传递时间与水平距离的关系，利用AUV的航位推算数据构建了虚拟长基线定位模型。随后，提出了两种不同的位置估计方法：一种是基于两步加权最小二乘的封闭解，另一种是通过半定松弛技术得到的半定规划（SDP）解。数值模拟和半物理实验表明，在考虑水声通道分层的情况下，所提出的封闭形式和基于sdp的定位方法都能提高定位精度。封闭形式的解决方案提供了更高的计算效率，而SDP方法实现了更好的定位性能-特别是当虚拟信标数量有限或测量噪声很大时。

{"title":"AUV single-beacon localization based on virtual long baseline with an isogradient sound velocity profile","authors":"Xiang Yu , Zhang Shi , Hongde Qin , Peilong Xu","doi":"10.1016/j.oceaneng.2026.124169","DOIUrl":"10.1016/j.oceaneng.2026.124169","url":null,"abstract":"<div><div>Under the influence of factors such as temperature, salinity, and water depth, the underwater acoustic propagation channel exhibits pronounced stratification, which in turn affects the performance of autonomous underwater vehicle (AUV) single-beacon localization systems. This study investigates the impact of acoustic stratification and focuses specifically on the AUV single-beacon localization method under an isogradient sound velocity profile (SVP) condition. By leveraging the relationship between acoustic signal transit time and horizontal range under an isogradient SVP, a virtual long baseline localization model is constructed using dead reckoning data from the AUV. Subsequently, two distinct position estimation methods are proposed: a closed-form solution based on two-step weighted least squares, and a semi-definite programming (SDP) solution obtained through semi-definite relaxation technique. Numerical simulations and semi-physical experiments demonstrate that by accounting for the stratification of the underwater acoustic channel, both the proposed closed-form and SDP-based solutions achieve enhanced positioning accuracy. The closed-form solution provides higher computational efficiency, whereas the SDP approach achieves superior localization performance–particularly when the number of virtual beacons is limited or measurement noise is substantial.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"350 ","pages":"Article 124169"},"PeriodicalIF":5.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145948011","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

Hydrodynamic analysis of a dual-mode bioinspired underwater robot featuring high-speed and high-manoeuvrability propulsion 高速高机动性双模仿生水下机器人的水动力分析

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-11 DOI: 10.1016/j.oceaneng.2026.124198

Liangjie Sun , Wenbin Su , Qiao Hu , Tangjia Zhang , Yangbin Zeng , Chuan Jiang , Shijie Li , Xindong Shi , Dayu Zhang

Undulatory propulsion offers inherent advantages in manoeuvrability and stealth for underwater robots. However, its low thrust density limits propulsion speed, and research on multi-degree-of-freedom manoeuvrability remains insufficient. To address this issue, this paper proposes an innovative dual-mode propulsion system. The system achieves this by morphing flexible fins to integrate both a high-speed spiral mode and a high-manoeuvrability undulatory mode, thereby overcoming the performance limitations of traditional single-mode undulatory propulsion.Furthermore, high-resolution self-propulsion simulations were conducted using a constrained immersed boundary method to investigate the hydrodynamic mechanisms of both propulsion modes. Results indicate that the spiral mode has a significant high-speed advantage. With a pitch of 1.26 m, the spiral mode achieved a maximum swimming speed of 1.62 m/s,which was 88.4 % higher than the undulatory mode, making it suitable for high-speed navigation tasks. The undulatory mode achieved higher low-speed efficiency and enabled agile manoeuvres through coordinated multi-fin control. It exhibited excellent attitude control capabilities, making it suitable for operations in confined spaces and flexible obstacle avoidance. Furthermore, prototype experiments validated the simulation model, with results closely matching across different modes. Overall, the proposed dual-mode underwater robot achieves a balanced combination of speed and manoeuvrability, providing new insights for the development of high-performance undulatory propulsion systems.

波动推进为水下机器人提供了固有的机动性和隐蔽性优势。但其推力密度低，限制了其推进速度，且对多自由度机动性能的研究不足。为了解决这一问题，本文提出了一种创新的双模推进系统。该系统通过变形柔性鳍实现高速螺旋模式和高机动性波动模式的结合，从而克服了传统单模波动推进的性能限制。此外，采用约束浸入边界法进行了高分辨率自推进仿真，研究了两种推进模式的水动力机制。结果表明，螺旋模式具有明显的高速优势。当桨距为1.26 m时，螺旋模式的最大游泳速度为1.62 m/s，比波动模式提高了88.4%，适合高速航行任务。波动模式实现了更高的低速效率，并通过多鳍协调控制实现灵活机动。它表现出优异的姿态控制能力，使其适合在密闭空间和灵活的避障操作。通过样机实验验证了仿真模型的正确性，不同模式下的仿真结果吻合较好。总体而言，所提出的双模水下机器人实现了速度和机动性的平衡组合，为高性能波动推进系统的发展提供了新的见解。

{"title":"Hydrodynamic analysis of a dual-mode bioinspired underwater robot featuring high-speed and high-manoeuvrability propulsion","authors":"Liangjie Sun , Wenbin Su , Qiao Hu , Tangjia Zhang , Yangbin Zeng , Chuan Jiang , Shijie Li , Xindong Shi , Dayu Zhang","doi":"10.1016/j.oceaneng.2026.124198","DOIUrl":"10.1016/j.oceaneng.2026.124198","url":null,"abstract":"<div><div>Undulatory propulsion offers inherent advantages in manoeuvrability and stealth for underwater robots. However, its low thrust density limits propulsion speed, and research on multi-degree-of-freedom manoeuvrability remains insufficient. To address this issue, this paper proposes an innovative dual-mode propulsion system. The system achieves this by morphing flexible fins to integrate both a high-speed spiral mode and a high-manoeuvrability undulatory mode, thereby overcoming the performance limitations of traditional single-mode undulatory propulsion.Furthermore, high-resolution self-propulsion simulations were conducted using a constrained immersed boundary method to investigate the hydrodynamic mechanisms of both propulsion modes. Results indicate that the spiral mode has a significant high-speed advantage. With a pitch of 1.26 m, the spiral mode achieved a maximum swimming speed of 1.62 m/s,which was 88.4 % higher than the undulatory mode, making it suitable for high-speed navigation tasks. The undulatory mode achieved higher low-speed efficiency and enabled agile manoeuvres through coordinated multi-fin control. It exhibited excellent attitude control capabilities, making it suitable for operations in confined spaces and flexible obstacle avoidance. Furthermore, prototype experiments validated the simulation model, with results closely matching across different modes. Overall, the proposed dual-mode underwater robot achieves a balanced combination of speed and manoeuvrability, providing new insights for the development of high-performance undulatory propulsion systems.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"350 ","pages":"Article 124198"},"PeriodicalIF":5.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947760","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

Wasserstein temporal GAN for ocean wave prediction with small training sets 基于小训练集的Wasserstein时态GAN海浪预测

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-11 DOI: 10.1016/j.oceaneng.2025.124122

Jiani Chen , Teng Gao , Yutong Song , Yao Zhang , Nicholas Townsend , Stephen Turnock , Richard Bucknall , Tianyi Zeng

Wave prediction is becoming increasingly important to provide optimal solutions in marine activities such as autonomous decision making and human activity planning. Learning-based algorithms require a sufficient amount of historical data for training, however, in marine scenarios, the acquisition of valid, high-quality wave data is frequently constrained by factors such as equipment limitations, harsh ocean conditions, or limited monitoring coverage. To address the challenge of sea wave prediction with small-scale training datasets, this paper proposes a new data augmentation model, WTGAN (Wasserstein Temporal Generative Adversarial Network). By capturing temporal dependencies and generating synthetic time series data, the WTGAN model aims to mitigate the data scarcity issue. The effectiveness of the new proposed model is validated by comparing the statistical properties of synthetic data, as well as the performance of three commonly-applied forecasting models with and without data augmentation. The performance of sea wave forecasting is assessed by the Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and Coefficient of Determination (R²), and is improved with the proposed WTGAN model by 5% to 12% under different wave conditions.

海浪预测在自主决策和人类活动规划等海洋活动中提供最佳解决方案变得越来越重要。基于学习的算法需要足够数量的历史数据进行训练，然而，在海洋场景中，有效、高质量的波浪数据的获取经常受到设备限制、恶劣海洋条件或有限监测覆盖等因素的限制。为了解决小规模训练数据集海浪预测的挑战，本文提出了一种新的数据增强模型WTGAN （Wasserstein Temporal Generative Adversarial Network）。通过捕获时间依赖性和生成合成时间序列数据，WTGAN模型旨在缓解数据稀缺性问题。通过比较合成数据的统计特性，以及三种常用预测模型在数据增强和不增强情况下的性能，验证了新模型的有效性。采用平均绝对误差（MAE）、均方根误差（RMSE）和决定系数（R2）对海浪预报效果进行了评价，在不同的海浪条件下，WTGAN模型的海浪预报效果提高了5% ~ 12%。

{"title":"Wasserstein temporal GAN for ocean wave prediction with small training sets","authors":"Jiani Chen , Teng Gao , Yutong Song , Yao Zhang , Nicholas Townsend , Stephen Turnock , Richard Bucknall , Tianyi Zeng","doi":"10.1016/j.oceaneng.2025.124122","DOIUrl":"10.1016/j.oceaneng.2025.124122","url":null,"abstract":"<div><div>Wave prediction is becoming increasingly important to provide optimal solutions in marine activities such as autonomous decision making and human activity planning. Learning-based algorithms require a sufficient amount of historical data for training, however, in marine scenarios, the acquisition of valid, high-quality wave data is frequently constrained by factors such as equipment limitations, harsh ocean conditions, or limited monitoring coverage. To address the challenge of sea wave prediction with small-scale training datasets, this paper proposes a new data augmentation model, WTGAN (Wasserstein Temporal Generative Adversarial Network). By capturing temporal dependencies and generating synthetic time series data, the WTGAN model aims to mitigate the data scarcity issue. The effectiveness of the new proposed model is validated by comparing the statistical properties of synthetic data, as well as the performance of three commonly-applied forecasting models with and without data augmentation. The performance of sea wave forecasting is assessed by the Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and Coefficient of Determination (<em>R</em><sup>2</sup>), and is improved with the proposed WTGAN model by 5% to 12% under different wave conditions.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"350 ","pages":"Article 124122"},"PeriodicalIF":5.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947758","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

Semi-active vibration control of monopile-supported offshore wind turbines at scour sites 冲刷场地单桩支撑海上风力发电机组半主动振动控制

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-11 DOI: 10.1016/j.oceaneng.2026.124190

Jian Zhang , Hao Ding , Jin-Ting Wang , Okyay Altay

Scouring can significantly impact the natural frequencies and dynamic responses of monopile-supported offshore wind turbines (OWTs) under the combined effects of wind, waves, and seismic loads. As scouring progresses, the passive vibration reduction devices commonly used in OWTs gradually lose their optimal tuning effects. In this study, we present an innovative numerical analysis of a semi-active toroidal tuned liquid column damper (S-TTLCD), specifically designed to effectively suppress multi-directional vibrations in monopile-supported OWTs. This is particularly targeted at enhancing the structural stability under the combined effects of wind, wave, and seismic forces in areas prone to scouring. The soil-pile interaction is modeled utilizing a

P - y

curve relationship, while the model of OWTs comprehensively integrates the impacts of multi-hazard loading conditions and diverse scouring depths to enable a rigorous systematic analysis. A sophisticated semi-active control strategy based on short-time Fourier transform (STFT) and displacement based groundhook (DBG) is devised, in which the natural frequency and damping of the S-TTLCD are precisely adjusted to match the responses of OWTs affected by scouring. The findings demonstrate that the S-TTLCD mitigates the dynamic responses of OWTs, outperforming the passive system, especially when the structural dynamic properties is altered due to scouring.

冲刷对单桩支撑海上风力发电机组在风、波、地震综合作用下的固有频率和动力响应有显著影响。随着冲刷的进行，常用的被动减振装置逐渐失去了最佳调谐效果。在这项研究中，我们提出了一种创新的半主动环形调谐液柱阻尼器（S-TTLCD）的数值分析，该阻尼器专门设计用于有效抑制单桩支撑的wot中的多向振动。这是特别针对在容易冲刷的地区，加强风、浪和地震力联合作用下的结构稳定性。土桩相互作用采用P - y曲线关系建模，而OWTs模型综合考虑了多灾种荷载条件和不同冲刷深度的影响，能够进行严格的系统分析。设计了一种基于短时傅里叶变换（STFT）和位移接地（DBG）的复杂半主动控制策略，精确调节S-TTLCD的固有频率和阻尼，以匹配受冲刷影响的wts的响应。研究结果表明，S-TTLCD减轻了owt的动态响应，优于被动系统，特别是当结构动态特性因冲刷而改变时。

{"title":"Semi-active vibration control of monopile-supported offshore wind turbines at scour sites","authors":"Jian Zhang , Hao Ding , Jin-Ting Wang , Okyay Altay","doi":"10.1016/j.oceaneng.2026.124190","DOIUrl":"10.1016/j.oceaneng.2026.124190","url":null,"abstract":"<div><div>Scouring can significantly impact the natural frequencies and dynamic responses of monopile-supported offshore wind turbines (OWTs) under the combined effects of wind, waves, and seismic loads. As scouring progresses, the passive vibration reduction devices commonly used in OWTs gradually lose their optimal tuning effects. In this study, we present an innovative numerical analysis of a semi-active toroidal tuned liquid column damper (S-TTLCD), specifically designed to effectively suppress multi-directional vibrations in monopile-supported OWTs. This is particularly targeted at enhancing the structural stability under the combined effects of wind, wave, and seismic forces in areas prone to scouring. The soil-pile interaction is modeled utilizing a <span><math><mrow><mi>P</mi><mo>−</mo><mi>y</mi></mrow></math></span> curve relationship, while the model of OWTs comprehensively integrates the impacts of multi-hazard loading conditions and diverse scouring depths to enable a rigorous systematic analysis. A sophisticated semi-active control strategy based on short-time Fourier transform (STFT) and displacement based groundhook (DBG) is devised, in which the natural frequency and damping of the S-TTLCD are precisely adjusted to match the responses of OWTs affected by scouring. The findings demonstrate that the S-TTLCD mitigates the dynamic responses of OWTs, outperforming the passive system, especially when the structural dynamic properties is altered due to scouring.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"350 ","pages":"Article 124190"},"PeriodicalIF":5.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947769","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

Holistic optimization and comparison of mooring systems for floating offshore wind turbines 海上浮式风力机系泊系统整体优化与比较

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-11 DOI: 10.1016/j.oceaneng.2025.124163

Magnus Daniel Kallinger , Hector del Pozo Gonzalez , Pau Trubat , Jose Luis Domínguez-García , Climent Molins

Mooring design is critical to the cost-efficiency of floating offshore wind projects located in deeper waters. This work presents a frequency-domain mooring-optimization framework for floating platforms that enables rapid concept mooring design screening and constraint checks, minimizing early-stage CAPEX. DLC 1.6 and DLC 1.2 are assessed for Ultimate Limit State and Fatigue Limit State, respectively, by Orcaflex’ frequency-domain module. An adaptive particle swarm optimization algorithm is developed in Python, featuring neighborhood regrouping and informed by variable constraint correlations to guide efficient search. The method allows independent variable settings for different line groups, supporting a wide range of materials and components. A static-dynamic stiffness model is applied to a variety of fiber ropes, with linearized integration of load-reduction devices. The methodology is applied on the WindCrete spar and Volturn-US semi-submersible, each with a 15 MW turbine under multidirectional co-aligned environmental conditions. The study moves beyond symmetric mooring assumptions, promoting line-specific, functionally targeted designs. Spars require more complex configurations, while semi-submersibles enable lower cost solutions. Anchors and chains are major cost drivers; Nylon is more economical than Polyester, and wire ropes outperform HMPE (high-modulus polyethylene) for high stiffness solutions. Load-reduction devices and buoyancy modules can be critical but are cost-sensitive. Correlation analysis reveals that especially line form, rope and forerunner chain characteristics, govern whether the mooring system becomes tension-, fatigue- or motion-critical with load-reduction devices acting as secondary tuning elements.

系泊设计对于深水浮式海上风电项目的成本效益至关重要。这项工作提出了一个用于浮式平台的频域系泊优化框架，可以实现快速的概念系泊设计筛选和约束检查，最大限度地减少早期的资本支出。通过Orcaflex的频域模块分别评估DLC 1.6和DLC 1.2的极限状态和疲劳极限状态。在Python中开发了一种自适应粒子群优化算法，该算法以邻域重组和变量约束相关性为特征，指导高效搜索。该方法允许为不同的线组设置独立变量，支持广泛的材料和组件。采用静态-动态刚度模型对多种纤维绳索进行了分析，并对减载装置进行了线性化集成。该方法应用于WindCrete桅杆船和volturnus半潜式船，每艘船在多向共向环境条件下都有一个15兆瓦的涡轮机。该研究超越了对称系泊假设，促进了线条特定的、功能针对性的设计。spar平台需要更复杂的配置，而半潜式平台则需要更低成本的解决方案。锚和锚链是主要的成本驱动因素；尼龙比聚酯更经济，钢丝绳在高刚度解决方案中优于HMPE（高模量聚乙烯）。减重装置和浮力模块至关重要，但对成本很敏感。相关分析表明，特别是缆绳形式、缆绳和前驱链的特性，决定了系泊系统是否成为张力、疲劳或运动临界，而减载装置作为次要调谐元件。

{"title":"Holistic optimization and comparison of mooring systems for floating offshore wind turbines","authors":"Magnus Daniel Kallinger , Hector del Pozo Gonzalez , Pau Trubat , Jose Luis Domínguez-García , Climent Molins","doi":"10.1016/j.oceaneng.2025.124163","DOIUrl":"10.1016/j.oceaneng.2025.124163","url":null,"abstract":"<div><div>Mooring design is critical to the cost-efficiency of floating offshore wind projects located in deeper waters. This work presents a frequency-domain mooring-optimization framework for floating platforms that enables rapid concept mooring design screening and constraint checks, minimizing early-stage CAPEX. DLC 1.6 and DLC 1.2 are assessed for Ultimate Limit State and Fatigue Limit State, respectively, by Orcaflex’ frequency-domain module. An adaptive particle swarm optimization algorithm is developed in Python, featuring neighborhood regrouping and informed by variable constraint correlations to guide efficient search. The method allows independent variable settings for different line groups, supporting a wide range of materials and components. A static-dynamic stiffness model is applied to a variety of fiber ropes, with linearized integration of load-reduction devices. The methodology is applied on the WindCrete spar and Volturn-US semi-submersible, each with a 15 MW turbine under multidirectional co-aligned environmental conditions. The study moves beyond symmetric mooring assumptions, promoting line-specific, functionally targeted designs. Spars require more complex configurations, while semi-submersibles enable lower cost solutions. Anchors and chains are major cost drivers; Nylon is more economical than Polyester, and wire ropes outperform HMPE (high-modulus polyethylene) for high stiffness solutions. Load-reduction devices and buoyancy modules can be critical but are cost-sensitive. Correlation analysis reveals that especially line form, rope and forerunner chain characteristics, govern whether the mooring system becomes tension-, fatigue- or motion-critical with load-reduction devices acting as secondary tuning elements.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"350 ","pages":"Article 124163"},"PeriodicalIF":5.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145947768","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 modeling of transient gas-liquid two-phase slug flow in a curved pipe 弯曲管内瞬态气液两相段塞流的数值模拟

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-11 DOI: 10.1016/j.oceaneng.2025.124156

Zhongheng Lai , Chengbin Liu , Jian Su

Slug flow is frequently encountered in curved pipelines and may induce severe pressure and load fluctuations, making its accurate prediction essential for flow assurance and structural integrity. This study develops a mathematical model based on the slug-tracking approach to predict transient gas-liquid slug flow in curved pipelines. The slug flow is modeled as a sequence of slug units, each divided into a liquid slug with entrained bubbles and a stratified bubble-liquid film region. The model incorporates momentum jumps, hydrostatic pressure effects, and curvature effects, while explicitly representing wake-induced bubble acceleration and the associated film backflow through interfacial balances. Validation against experimental data confirms that the model reproduces key slug flow features with high fidelity. The results show that the modeling framework consistently captures the spatiotemporal evolution of slug flow, including pressure reduction, gas expansion, bubble acceleration, and film backflow. Statistical analysis reveals characteristic transitions in flow distributions, with slug frequency and bubble velocity strongly dependent on the gas-liquid velocity ratio. These findings highlight the inertia-gravity interplay governing slug flow dynamics and provide insights for flow assurance and offshore pipeline design. Moreover, the predicted slug characteristics can offer critical data support for fluid-structure interaction, structural integrity assessments, safe operation, and mitigation strategies such as controlled start-up, throttling, and slug suppression devices.

段塞流在弯曲管道中经常遇到，并可能引起严重的压力和负荷波动，因此对其进行准确预测对于流动保证和结构完整性至关重要。本文建立了基于段塞流跟踪方法的数学模型，用于预测弯曲管道中瞬态气液段塞流。段塞流被建模为一系列段塞流单元，每个单元分为带夹带气泡的液体段塞流和分层的气泡-液膜区域。该模型结合了动量跳跃、静水压力效应和曲率效应，同时明确地表示了尾迹诱导的气泡加速度和通过界面平衡的相关膜回流。对实验数据的验证证实，该模型以高保真度再现了段塞流的关键特征。结果表明，该模型框架能够较好地反映段塞流的时空演化过程，包括压力降低、气体膨胀、气泡加速和膜回流。统计分析揭示了流动分布的特征转变，其中段塞频率和气泡速度强烈依赖于气液速度比。这些发现突出了控制段塞流动力学的惯性-重力相互作用，并为流动保障和海上管道设计提供了见解。此外，预测的段塞流特性可以为流固耦合、结构完整性评估、安全操作和缓解策略（如受控启动、节流和段塞流抑制装置）提供关键数据支持。

{"title":"Numerical modeling of transient gas-liquid two-phase slug flow in a curved pipe","authors":"Zhongheng Lai , Chengbin Liu , Jian Su","doi":"10.1016/j.oceaneng.2025.124156","DOIUrl":"10.1016/j.oceaneng.2025.124156","url":null,"abstract":"<div><div>Slug flow is frequently encountered in curved pipelines and may induce severe pressure and load fluctuations, making its accurate prediction essential for flow assurance and structural integrity. This study develops a mathematical model based on the slug-tracking approach to predict transient gas-liquid slug flow in curved pipelines. The slug flow is modeled as a sequence of slug units, each divided into a liquid slug with entrained bubbles and a stratified bubble-liquid film region. The model incorporates momentum jumps, hydrostatic pressure effects, and curvature effects, while explicitly representing wake-induced bubble acceleration and the associated film backflow through interfacial balances. Validation against experimental data confirms that the model reproduces key slug flow features with high fidelity. The results show that the modeling framework consistently captures the spatiotemporal evolution of slug flow, including pressure reduction, gas expansion, bubble acceleration, and film backflow. Statistical analysis reveals characteristic transitions in flow distributions, with slug frequency and bubble velocity strongly dependent on the gas-liquid velocity ratio. These findings highlight the inertia-gravity interplay governing slug flow dynamics and provide insights for flow assurance and offshore pipeline design. Moreover, the predicted slug characteristics can offer critical data support for fluid-structure interaction, structural integrity assessments, safe operation, and mitigation strategies such as controlled start-up, throttling, and slug suppression devices.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"350 ","pages":"Article 124156"},"PeriodicalIF":5.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145948010","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

Experimental study on dynamic response of offshore wind turbine structures under asymmetric wave and wind loads 海上风力机结构在非对称波风荷载作用下的动力响应试验研究

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.oceaneng.2026.124257

Zhang Xiao-ling, Zhou Guang-li, Zhang Bing-jie, Xu Cheng-shun

Offshore wind turbine (OWT) structures are subjected to wind and wave loads throughout their service period. These loads typically exhibit random characteristics, different directions, and asymmetry. In the present research, the dynamic response of OWT has been simplified by representing wind and wave loads as a unidirectional horizontal force. However, the changing direction of wind and waves is demonstrated through extensive ocean field measurements. When only the co-directional action of wind and wave loads is considered, the resulting dynamic response is not representative of actual conditions. To address this issue, a self-developed loading simulation system designed for complex marine environmental conditions is employed. Under physical model test conditions at a scale of 1:100, experimental studies are conducted on the dynamic response of OWT under asymmetric wind-wave loads. Based on measured data from the eastern sea area, typical wind-wave misalignment angles are selected. And the dynamic response is analyzed at different misalignment angles and wind speeds. The significant impact of asymmetric wind-wave loads on the dynamic response of OWT has been demonstrated by the results of the study. By comparing the maximum bending moment at mud surface under different conditions, the condition with the wind speed of 1.8 m/s and the 22.5° wind-wave misalignment angle is identified as potentially the most unfavorable. The design, operation, and maintenance of OWT structures in eastern sea areas have gained significant research significance and engineering value through this study.

海上风力发电机结构在其整个使用期间都要承受风浪荷载。这些载荷通常表现出随机特性、不同方向和不对称性。在本研究中，通过将风浪荷载表示为单向水平力，简化了OWT的动力响应。然而，通过广泛的海洋实地测量，可以证明风和波的方向变化。当只考虑风浪荷载的共向作用时，得到的动力响应不能代表实际情况。为了解决这一问题，采用了自行开发的针对复杂海洋环境条件的加载仿真系统。在1:100比例尺的物理模型试验条件下，对非对称风浪荷载作用下OWT的动力响应进行了试验研究。根据东部海域实测资料，选取典型的风浪失向角。分析了不同对中角度和风速下的动力响应。研究结果表明，非对称风浪荷载对水轮机动力响应有显著影响。通过对比不同工况下泥面最大弯矩，确定风速为1.8 m/s、风浪失向角为22.5°的工况为潜在最不利工况。本研究对东部海域水运构筑物的设计、运行和维护具有重要的研究意义和工程价值。

{"title":"Experimental study on dynamic response of offshore wind turbine structures under asymmetric wave and wind loads","authors":"Zhang Xiao-ling, Zhou Guang-li, Zhang Bing-jie, Xu Cheng-shun","doi":"10.1016/j.oceaneng.2026.124257","DOIUrl":"10.1016/j.oceaneng.2026.124257","url":null,"abstract":"<div><div>Offshore wind turbine (OWT) structures are subjected to wind and wave loads throughout their service period. These loads typically exhibit random characteristics, different directions, and asymmetry. In the present research, the dynamic response of OWT has been simplified by representing wind and wave loads as a unidirectional horizontal force. However, the changing direction of wind and waves is demonstrated through extensive ocean field measurements. When only the co-directional action of wind and wave loads is considered, the resulting dynamic response is not representative of actual conditions. To address this issue, a self-developed loading simulation system designed for complex marine environmental conditions is employed. Under physical model test conditions at a scale of 1:100, experimental studies are conducted on the dynamic response of OWT under asymmetric wind-wave loads. Based on measured data from the eastern sea area, typical wind-wave misalignment angles are selected. And the dynamic response is analyzed at different misalignment angles and wind speeds. The significant impact of asymmetric wind-wave loads on the dynamic response of OWT has been demonstrated by the results of the study. By comparing the maximum bending moment at mud surface under different conditions, the condition with the wind speed of 1.8 m/s and the 22.5° wind-wave misalignment angle is identified as potentially the most unfavorable. The design, operation, and maintenance of OWT structures in eastern sea areas have gained significant research significance and engineering value through this study.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"349 ","pages":"Article 124257"},"PeriodicalIF":5.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928486","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 Bayesian network framework for evidence-based risk analysis of offshore wind turbines 基于证据的海上风力发电机风险分析贝叶斯网络框架

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.oceaneng.2025.124162

Utkarsh Bhardwaj, C. Guedes Soares

This study presents a comprehensive methodology for assessing the risk of offshore wind turbine failures using a probabilistic framework based on Bayesian Networks. Drawing on a dataset of 1753 failure events from offshore wind farms, this study provides failure patterns through systematic statistical analysis, comprising failure frequencies, criticalities, and shutdown distributions across offshore wind turbines’ sub-components. Chi-square tests are conducted to identify statistical relationships among fault indicators, maintenance actions and subcomponents. A Bayesian Network model is created, integrating expert knowledge and evidence of failure data to develop relationships among components, sub-components, and failure causes. Sensitivity analyses identify key drivers of system failure, highlighting the influence of critical units such as generators, converters, and cooling systems. This study has two facets, statistical characterisation and probabilistic modelling, which allow accurate diagnosis of failure scenarios and support informed, evidence-based decision-making. The findings are directly applicable to improving operational reliability and guiding maintenance planning in offshore wind farms.

本研究提出了一种基于贝叶斯网络的概率框架来评估海上风力涡轮机故障风险的综合方法。本研究利用海上风电场1753个故障事件的数据集，通过系统的统计分析提供了故障模式，包括海上风力涡轮机子部件的故障频率、临界程度和停机分布。通过卡方检验确定故障指标、维修行为和子组件之间的统计关系。建立贝叶斯网络模型，整合专家知识和故障数据证据，建立组件、子组件和故障原因之间的关系。敏感性分析确定了系统故障的关键驱动因素，突出了发电机、变流器和冷却系统等关键单元的影响。这项研究有两个方面，统计特征和概率建模，可以准确诊断故障场景，并支持知情的、基于证据的决策。研究结果可直接应用于提高海上风电场的运行可靠性和指导维护计划。

{"title":"A Bayesian network framework for evidence-based risk analysis of offshore wind turbines","authors":"Utkarsh Bhardwaj, C. Guedes Soares","doi":"10.1016/j.oceaneng.2025.124162","DOIUrl":"10.1016/j.oceaneng.2025.124162","url":null,"abstract":"<div><div>This study presents a comprehensive methodology for assessing the risk of offshore wind turbine failures using a probabilistic framework based on Bayesian Networks. Drawing on a dataset of 1753 failure events from offshore wind farms, this study provides failure patterns through systematic statistical analysis, comprising failure frequencies, criticalities, and shutdown distributions across offshore wind turbines’ sub-components. Chi-square tests are conducted to identify statistical relationships among fault indicators, maintenance actions and subcomponents. A Bayesian Network model is created, integrating expert knowledge and evidence of failure data to develop relationships among components, sub-components, and failure causes. Sensitivity analyses identify key drivers of system failure, highlighting the influence of critical units such as generators, converters, and cooling systems. This study has two facets, statistical characterisation and probabilistic modelling, which allow accurate diagnosis of failure scenarios and support informed, evidence-based decision-making. The findings are directly applicable to improving operational reliability and guiding maintenance planning in offshore wind farms.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"349 ","pages":"Article 124162"},"PeriodicalIF":5.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928492","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

Floater motions of a 15 MW floating offshore wind turbine under extreme waves after mooring line failure 15 MW海上浮式风力发电机系泊缆绳失效后在极端波浪下的浮子运动

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2026-01-10 DOI: 10.1016/j.oceaneng.2026.124254

Guoyan Li , Yan Li , Qiang Zhu , Bin Wang , Yiting Feng , Ouming Su , Yiwen Cui , Haoran Li

According to observations, the operation of floating offshore wind turbine (FOWT) faces the potential hazard of successive extreme waves (SEWs). These waves increase the transient response of the floater and threaten the system safety, especially after mooring line failure. To understand this issue, we focus on the effects of extreme waves with two large crests. A fully coupled model is developed to investigate the floater motions of a 15 MW semi-submersible FOWT under the impact of four types of SEWs with different impact times. The blade element momentum theory, three-dimensional potential flow theory, and finite element theory are employed for the aero-hydro-elastic model. Mooring failure amplification effects are quantified and assessed using a novel impact factor. Our work demonstrates that the floater motions exhibit variations in both amplitude and phase under the SEW impacts. The increase in wave height amplifies the wave loads, leading to increases in the wavelet energy at the wave frequency and natural frequencies. The out-of-horizontal-plane motions are less affected by the mooring line failure compared with the in-horizontal-plane motions as the mooring system primarily provides horizontal stiffness. Notably, it is interesting to find that the mooring line failure reduces the pitch motion in SEWs compared with the intact mooring system.

根据观测，海上浮式风电机组的运行面临连续极端浪的潜在危害。这些波浪增加了浮子的瞬态响应，威胁着系统的安全，特别是在系泊线失效后。为了理解这个问题，我们关注具有两个大波峰的极端波浪的影响。建立了一种全耦合模型，研究了15 MW半潜式FOWT在四种不同冲击次数的SEWs冲击下的浮子运动。气动-水弹模型采用叶片单元动量理论、三维势流理论和有限元理论。采用一种新的影响因子对锚泊失效放大效应进行了量化和评估。我们的工作表明，在SEW冲击下，漂浮物运动表现出幅度和相位的变化。波高的增加放大了波浪荷载，导致波频和固有频率处的小波能量增加。由于系泊系统主要提供水平刚度，与水平平面内运动相比，系泊线破坏对水平平面外运动的影响较小。值得注意的是，有趣的是，与完整的系泊系统相比，系泊线失效减少了SEWs的俯仰运动。

{"title":"Floater motions of a 15 MW floating offshore wind turbine under extreme waves after mooring line failure","authors":"Guoyan Li , Yan Li , Qiang Zhu , Bin Wang , Yiting Feng , Ouming Su , Yiwen Cui , Haoran Li","doi":"10.1016/j.oceaneng.2026.124254","DOIUrl":"10.1016/j.oceaneng.2026.124254","url":null,"abstract":"<div><div>According to observations, the operation of floating offshore wind turbine (FOWT) faces the potential hazard of successive extreme waves (SEWs). These waves increase the transient response of the floater and threaten the system safety, especially after mooring line failure. To understand this issue, we focus on the effects of extreme waves with two large crests. A fully coupled model is developed to investigate the floater motions of a 15 MW semi-submersible FOWT under the impact of four types of SEWs with different impact times. The blade element momentum theory, three-dimensional potential flow theory, and finite element theory are employed for the aero-hydro-elastic model. Mooring failure amplification effects are quantified and assessed using a novel impact factor. Our work demonstrates that the floater motions exhibit variations in both amplitude and phase under the SEW impacts. The increase in wave height amplifies the wave loads, leading to increases in the wavelet energy at the wave frequency and natural frequencies. The out-of-horizontal-plane motions are less affected by the mooring line failure compared with the in-horizontal-plane motions as the mooring system primarily provides horizontal stiffness. Notably, it is interesting to find that the mooring line failure reduces the pitch motion in SEWs compared with the intact mooring system.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"349 ","pages":"Article 124254"},"PeriodicalIF":5.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928493","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