Ocean Engineering最新文献_第10页

Numerical research on hydrodynamic performance of toroidal propeller under the influence of geometric parameters 几何参数影响下环形螺旋桨流体力学性能的数值研究

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-05 DOI: 10.1016/j.oceaneng.2024.119704

Chunhui Wang , Shun Liu , Kun Xia , Chao Wang , Liyu Ye

Recent advancements in high-efficiency, low-noise toroidal propellers have garnered significant interest due to their potential to revolutionize maritime propulsion. This study addresses this gap by leveraging established geometrical modeling methods for toroidal propellers to design a novel variant, and assesses its hydrodynamic performance using the Reynolds-averaged Navier-Stokes (RANS) method coupled with the Shear Stress Transport (SST) k-ω turbulence model. First, the paper introduces the toroidal propeller concept and modeling method before analyzing the impact of grid size on numerical simulations. The correspondence between numerical results and experimental data is then established to validate the computational model's accuracy. Following this, the study explores the hydrodynamic performance of the toroidal propeller, including pressure distribution on the blade surface and the flow field dynamics in the propeller's wake across varying advance coefficients. Subsequently, it examines the influence of geometric parameters such as axis span ratios, lateral angles, roll angles, and vertical angles, on the hydrodynamic performance, elucidating their effects on the pressure distribution profiles at radial sections, thrust coefficient, and open water efficiency. The findings provide substantial guidance for the geometric parameter selection in the optimal design of future toroidal propellers.

高效率、低噪音环形螺旋桨的最新进展引起了人们的极大兴趣，因为它们有可能彻底改变海上推进方式。本研究针对这一空白，利用已建立的环形螺旋桨几何建模方法设计了一种新型变体，并使用雷诺平均纳维-斯托克斯（RANS）方法和剪应力传输（SST）k-ω 湍流模型对其流体力学性能进行了评估。本文首先介绍了环形螺旋桨的概念和建模方法，然后分析了网格大小对数值模拟的影响。然后建立了数值结果与实验数据之间的对应关系，以验证计算模型的准确性。随后，研究探讨了环形螺旋桨的流体力学性能，包括叶片表面的压力分布和螺旋桨尾流在不同推进系数下的流场动力学。随后，研究探讨了轴跨比、横向角、滚动角和垂直角等几何参数对流体动力学性能的影响，阐明了它们对径向截面压力分布剖面、推力系数和开水效率的影响。研究结果为未来环形螺旋桨优化设计中的几何参数选择提供了实质性指导。

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引用次数: 0

A mixed stochastic waves model for analyzing offshore structures considering engineering characteristics correlation of wind-generated-wave and swell 用于分析近海结构的混合随机波浪模型，考虑风生波和涌浪的工程特性相关性

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-05 DOI: 10.1016/j.oceaneng.2024.119671

Gang Li, Yunmu Jiang, Dinghao Yu, Zhiqian Dong

In the marine environment, offshore structures face mixed stochastic waves, including wind-generated waves and swells. Current design codes often overlook swells, leading to underestimations of environmental loads and structural responses, especially for flexible structures, potentially causing resonance and instability. Wind-generated waves and swells have distinct generation mechanisms, but their characteristics, such as significant wave height and average period, show a statistical correlation due to their interaction. Thus, a mixed stochastic wave model is needed to reflect both wave types and their correlation accurately. This study investigates the correlation of wave characteristics and the power density spectrum (PSD) between wind-generated waves and swells using measured data, providing a comprehensive understanding of mixed wave interactions. The joint probability density model of wave characteristics is discussed via Vine Copula theory. A framework for obtaining mixed wave loads is developed using the Proper Orthogonal Decomposition (POD) method, treating waves as a 1 dimension - 2 variables (1D-2V) stochastic vector process. The model is applied to assess the dynamic response of a 5 MW mono-pile offshore wind turbine (OWT). Results show that swells significantly increase the internal force and bending moment demands, highlighting the necessity of including swells in offshore structure design and analysis.

在海洋环境中，近海结构面临着混合随机波浪，包括风产生的波浪和涌浪。目前的设计规范往往忽略了涌浪，导致对环境荷载和结构响应估计不足，尤其是对柔性结构而言，有可能造成共振和不稳定。风引起的波浪和涌浪具有不同的产生机制，但由于它们之间的相互作用，它们的特征（如显著波高和平均周期）显示出统计相关性。因此，需要一个混合随机波浪模型来准确反映这两种波浪类型及其相关性。本研究利用实测数据研究了风成波和涌浪之间的波浪特征和功率密度谱（PSD）的相关性，从而全面了解混合波浪的相互作用。通过 Vine Copula 理论讨论了波浪特征的联合概率密度模型。利用适当正交分解（POD）方法，将波浪视为一维-两变量（1D-2V）随机向量过程，建立了一个获取混合波浪载荷的框架。该模型用于评估 5 兆瓦单桩海上风力涡轮机（OWT）的动态响应。结果表明，海浪大大增加了内力和弯矩需求，突出了将海浪纳入海上结构设计和分析的必要性。

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引用次数: 0

An accelerated corrosion-fatigue testing method for marine high-strength steel based on equivalence principle of fatigue crack growth 基于疲劳裂纹增长等效原理的船用高强度钢加速腐蚀疲劳试验方法

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-05 DOI: 10.1016/j.oceaneng.2024.119706

Ruonan Zhang , Pengyu Wei , Ke Wang , Peilong Song , Xin Guo , Qingbo Zeng , Shengpeng Li

The corrosion-fatigue test is widely used to assess marine equipment. However, due to the low-frequency and high-cycle loading of marine equipment in service, conventional test methods require long cycle times and high costs. This makes it challenging to meet the rapid evaluation demands associated with equipment development effectively. In this study, an accelerated corrosion test method was proposed for steel by adjusting the composition, temperature, pH and H₂O₂ concentration of environment. Fatigue crack growth tests were conducted under various corrosion environments and load frequencies. The matching relationships between corrosion fatigue acceleration multiplier, corrosion environment parameters and load parameters were established. Additionally, a corrosion fatigue acceleration test method was proposed based on the equivalent principle of fatigue crack growth. The results show that effective coupling between corrosion and fatigue can be achieved by gradually reducing the load frequency as the stress intensity factor amplitude increases throughout the crack growth process. It is consistent with the trend of fatigue crack growth rate in the seawater environment. The 4.85% fatigue life deviation and the 15.68 times corrosion fatigue acceleration can be achieved by our method. This work improves the accuracy and reliability of fatigue performance evaluation for offshore equipment.

腐蚀疲劳试验被广泛用于评估船用设备。然而，由于船用设备在使用中的低频率和高循环负载，传统的测试方法需要较长的循环时间和较高的成本。这使得有效满足与设备开发相关的快速评估需求面临挑战。本研究通过调整环境的成分、温度、pH 值和 H2O2 浓度，提出了一种钢材加速腐蚀试验方法。在不同的腐蚀环境和载荷频率下进行了疲劳裂纹生长试验。建立了腐蚀疲劳加速度乘数、腐蚀环境参数和载荷参数之间的匹配关系。此外，还提出了一种基于疲劳裂纹生长等效原理的腐蚀疲劳加速试验方法。结果表明，在整个裂纹生长过程中，随着应力强度因子振幅的增加，逐渐降低载荷频率可以实现腐蚀与疲劳的有效耦合。这与海水环境中疲劳裂纹增长速率的趋势一致。我们的方法可实现 4.85% 的疲劳寿命偏差和 15.68 倍的腐蚀疲劳加速度。这项工作提高了海洋工程设备疲劳性能评估的准确性和可靠性。

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引用次数: 0

Hybrid underwater imaging for the tri-dimensional inspection of critical structural elements in offshore platforms 用于海上平台关键结构件三维检测的混合水下成像技术

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-05 DOI: 10.1016/j.oceaneng.2024.119658

Pedro Nuno Leite , Pedro Nuno Pereira , João M.M. Dionísio , Andry Maykol Pinto

Offshore wind farms face harsh maritime conditions, prompting the use of sacrificial anodes to prevent rapid structural degradation. Regular maintenance and replacement of these elements are vital to ensure ongoing corrosion protection, maintain structural integrity, and optimize efficiency. This article details the design and validation of the MARESye hybrid underwater imaging system, capable of retrieving heterogeneous tri-dimensional information with millimetric precision for the close-range inspection of submerged critical structures. The optical prowess of the system is first validated during low turbidity trials where the volumetric properties of a decommissioned anode are reconstructed with absolute errors down to 0.0008 m, and its spatial dimensions are depicted with sub-millimeter precision accounting for relative errors as low as 0.31%. MARESye is later equipped as payload in a commercial ROV during a real environment inspection mission at the ATLANTIS Coastal Test Center. This experiment sees the sensor provide live reconstructions of a sacrificial anode, revealing a biofouling layer of approximately 0.0130 m thickness. The assessment of the high-fidelity 2D/3D information obtained from the MARESye sensor demonstrates its potential to enhance the situational awareness of underwater vehicles, fostering reliable O&M procedures.

海上风电场面临着恶劣的海洋条件，因此需要使用牺牲阳极来防止结构快速退化。定期维护和更换这些元件对于确保持续的腐蚀保护、保持结构完整性和优化效率至关重要。本文详细介绍了 MARESye 混合水下成像系统的设计和验证，该系统能够以毫米级精度检索异构三维信息，用于水下关键结构的近距离检测。该系统的光学性能首先在低浊度试验中得到验证，在低浊度试验中，对退役阳极的体积特性进行了重建，绝对误差低至 0.0008 米，对其空间尺寸的描述精度达到亚毫米级，相对误差低至 0.31%。在 ATLANTIS 海岸测试中心进行的实际环境检测任务中，MARESye 后来被作为有效载荷装备到商用遥控潜水器上。在这次实验中，传感器对牺牲阳极进行了实时重建，揭示了厚度约为 0.0130 米的生物污损层。对 MARESye 传感器获得的高保真 2D/3D 信息进行的评估表明，该传感器具有提高水下航行器态势感知能力、促进可靠的运行和维护程序的潜力。

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引用次数: 0

Mechanical modulation wave energy harvesting for self-powered marine environment monitoring 用于自供电海洋环境监测的机械调制波能采集技术

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-04 DOI: 10.1016/j.oceaneng.2024.119683

Hong-Xiang Zou , Wen-Zhuo Zhou , Chang-Sheng Su , Ding-Hua Guo , Lin-Chuan Zhao , Qiu-Hua Gao , Ke-Xiang Wei

Small-scale wave energy harvesting can be used for self-powered marine environmental monitoring, with the advantages of sustainability, convenience, and environmental protection. The low-frequency and strong random fluctuations of ocean wave motion are not conducive to electromechanical conversion. In this paper, we propose a mechanically modulated wave energy harvester embedded with interference-free triboelectric nanogenerators. The mass pendulum oscillates under irregular low-frequency wave excitation, and then the oscillation is mechanically modulated into a unidirectional high-speed rotation of four permanent magnet disks. The elastic parts on both sides of the mass pendulum are functionalized into multi-layered folding triboelectric nanogenerators, which neither increase the volume of the wave energy harvesting system nor affect the operation of the electromagnetic generator. The prototype was manufactured and the experimental results show that the sum of the average power of the prototype is 4.8 W under excitation at a frequency of 3 Hz and a inclination angle of 40°. The 0.47 F capacitor can be charged to 5 V in 80 s by the prototype under the wave excitation generated by push plate, and then used for self-powered marine environmental monitoring (illumination, temperature and pH) and wireless information transmission.

小规模波浪能采集可用于自供电海洋环境监测，具有可持续性、便利性和环保等优点。海洋波浪运动的低频和强随机波动不利于机电转换。本文提出了一种嵌入无干扰三电纳米发电机的机械调制波浪能收集器。质量摆在不规则低频波激励下摆动，然后通过机械调制将摆动转化为四个永磁盘的单向高速旋转。质量摆两侧的弹性部件被功能化为多层折叠式三电纳米发电机，既不增加波能收集系统的体积，也不影响电磁发电机的工作。原型已制造完成，实验结果表明，在频率为 3 Hz、倾角为 40° 的激励下，原型的平均功率之和为 4.8 W。在推板产生的波激励下，原型机可在 80 秒内将 0.47 F 的电容器充电至 5 V，然后用于自供电海洋环境监测（照度、温度和酸碱度）和无线信息传输。

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引用次数: 0

Risk-aware stochastic ship routing using constrained continuous belief tree search 使用受限连续信念树搜索的风险感知随机船舶路由选择

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-04 DOI: 10.1016/j.oceaneng.2024.119581

Andre Nuñez , Jennifer Wakulicz , Felix H. Kong , Alberto González-Cantos , Robert Fitch

Improved route planning for commercial shipping can enable reduced environmental impact, improve ship safety records, and lower fuel and maintenance costs. A fundamental challenge is to design ship routing algorithms that can contend with uncertain weather forecasts and real-world models of ship performance and safety. This paper introduces a stochastic ship routing framework that uses the conditional value-at-risk (CVaR) metric to guide the behaviour of a modified Continuous Belief Tree Search (CBTS) algorithm to find a safe and fuel-efficient long-haul shipping route. Our method provides a principled means to utilise a probabilistic representation of weather forecasts derived from ensemble forecasting for the purpose of route planning and allows for a user-defined threshold of risk tolerance. Another key advantage of our method is its ability to dynamically choose candidate route waypoints using weather-dependent estimates of fuel and safety information. Evaluation of long-haul routes through the Atlantic, Pacific and Indian oceans using real-world ship performance models and weather forecasts show considerable improvements in fuel usage and computation time compared to state-of-the-art ship routing algorithms.

改进商业航运的航线规划可以减少对环境的影响，改善船舶安全记录，降低燃料和维护成本。一个基本的挑战是设计出能够应对不确定天气预报和船舶性能与安全真实世界模型的船舶航线算法。本文介绍了一种随机船舶航线框架，该框架使用条件风险值（CVaR）指标来指导改进的连续信念树搜索（CBTS）算法的行为，以找到一条安全且省油的长途航运路线。我们的方法提供了一种原则性方法，利用集合预报得出的天气预报概率表示法进行航线规划，并允许用户自定义风险容忍度阈值。我们的方法的另一个主要优势是，它能够利用与天气相关的燃料和安全信息估算值，动态选择候选航线航点。利用真实世界的船舶性能模型和天气预报对穿越大西洋、太平洋和印度洋的长途航线进行的评估显示，与最先进的船舶航线算法相比，该方法在燃料使用和计算时间方面都有显著改善。

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引用次数: 0

Economics-constrained tidal turbine array layout optimisation at the Putuoshan–Hulu island waterway 普陀山-葫芦岛水道经济约束下的潮汐涡轮机阵列布局优化

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-04 DOI: 10.1016/j.oceaneng.2024.119618

Can Zhang , Xiaoming Cheng , Athanasios Angeloudis , Stephan C. Kramer , Chengsheng Wu , Ying Chen , Matthew D. Piggott

For the successful large scale commercialisation of the tidal stream energy industry it is imperative to consider array revenue rather than simply array power performance. This article reports on the application of a gradient-based optimisation algorithm to establish the optimal array size and layout at the Putuoshan–Hulu Islands waterway. Array economic viability is considered within the optimisation by introducing a break even power concept. Results show that the break even power constraint promotes increased power output per turbine. In response, the overall turbine number decreases due to economics-constraints, leading to an overall reduction in overall array energy yield. Thus, array profit decreases with increments in break even power. A hypothetical practical constraint linking water depth and array cost is also considered, demonstrating an intricate relationship between array design and spatial variability. Finally, using these numerical experiments, we derive development priority maps based on the optimised turbine layouts in order to help guide the tidal stream energy developments in the Putuoshan–Hulu Islands waterway.

要成功实现潮汐流能源产业的大规模商业化，必须考虑阵列收益，而不仅仅是阵列功率性能。本文报告了在普陀山-葫芦岛水道应用梯度优化算法确定最佳阵列规模和布局的情况。通过引入收支平衡功率概念，在优化过程中考虑了阵列的经济可行性。结果表明，收支平衡功率约束促进了每台风机输出功率的增加。与此相对应的是，由于经济性限制，涡轮机的总数量会减少，从而导致整个阵列的总发电量下降。因此，阵列利润会随着收支平衡功率的增加而减少。此外，还考虑了水深与阵列成本之间的假定实际限制，展示了阵列设计与空间变化之间错综复杂的关系。最后，利用这些数值实验，我们根据优化的涡轮机布局得出了开发优先级图，以帮助指导普陀山-葫芦岛水道的潮汐流能源开发。

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引用次数: 0

Traffic complexity assessment on the malacca strait with traffic zone matrix based on AIS data 基于 AIS 数据的交通区矩阵评估马六甲海峡的交通复杂性

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-04 DOI: 10.1016/j.oceaneng.2024.119687

Dapei Liu , Zihao Liu , Hooi-Siang Kang , Chee-Loon Siow , C. Guedes Soares

This study proposes a novel and feasible framework for assessing maritime traffic complexity, utilising historical Automatic Identification System data to extract dynamic traffic characteristics of sea waters and quantify the corresponding maritime traffic complexity. The processed historical statistics are initially segmented into subsets according to different geographic traffic cells based on traffic zones. Subsequently, a Radial Basis Function regression model with a Gaussian kernel is employed to extract dynamic traffic parameters at the central coordinates of each geographic traffic zone based on subsets. The dynamic parameters derived from nonlinear regression and complexity sub-models are ultimately applied in maritime traffic complexity identification. The effectiveness of the proposed framework is validated through complexity assessments in selected areas of Malacca Strait. Empirical results are significant for maritime shipping research on data-driven traffic complexity monitoring and digitalised decision support.

本研究提出了一个新颖可行的海上交通复杂性评估框架，利用自动识别系统的历史数据来提取海域的动态交通特征，并量化相应的海上交通复杂性。经过处理的历史统计数据首先根据不同的地理交通单元按交通区域划分为若干子集。随后，采用带有高斯核的径向基函数回归模型，根据子集提取每个地理交通区中心坐标处的动态交通参数。从非线性回归和复杂性子模型中得出的动态参数最终被应用于海洋交通复杂性识别。通过对马六甲海峡选定区域的复杂性评估，验证了所提框架的有效性。实证结果对数据驱动的交通复杂性监控和数字化决策支持方面的海运研究具有重要意义。

引用次数: 0

Enhancing underwater thruster anomaly detection with support vector glow encoding description 利用支持向量辉光编码描述加强水下推进器异常检测

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-04 DOI: 10.1016/j.oceaneng.2024.119655

Wenliao Du , Zihan Xiong , Pengxiang Zhu , Ziqiang Pu , Chuan Li , Dongdong Hou

As the driving system of autonomous underwater vehicles (AUVs), the healthy operation of underwater thrusters is crucial to ensure the performance of AUVs. Due to the challenge of obtaining faulty samples during normal operation, anomaly detection of underwater thrusters is often carried out using only normal samples. To address this, Support Vector Glow Encoding Description (SVGED) is proposed for anomaly detection of underwater thrusters trained with only normal samples. Specifically, the deep features of the operational vibration signals collected from the underwater thruster are extracted by a deep convolutional autoencoder based on a glow model. The glow-encoded data are then used to identify the boundary of normal operation for the underwater thruster. When a new sample enters the trained SVGED model, it can be effectively identified as representing a normal or anomalous condition of the underwater thruster. The developed SVGED was evaluated using AUV experiments. When using the proposed SVGED method, the accuracy reaches 99.81%, Results show that the proposed method can effectively real time detect anomalies in the underwater thruster compared to other methods. It lays the foundation for ensuring the healthy operation of AUVs.

作为自主潜水器（AUV）的驱动系统，水下推进器的健康运行对确保 AUV 的性能至关重要。由于难以获得正常运行时的故障样本，水下推进器的异常检测通常只使用正常样本。针对这一问题，提出了支持向量光晕编码描述（SVGED），用于仅使用正常样本训练的水下推进器异常检测。具体来说，从水下推进器收集到的运行振动信号的深度特征由基于辉光模型的深度卷积自动编码器提取。然后使用辉光编码数据来识别水下推进器正常运行的边界。当一个新样本进入训练有素的 SVGED 模型时，它可以被有效地识别为代表水下推进器的正常或异常状态。利用 AUV 实验对所开发的 SVGED 进行了评估。结果表明，与其他方法相比，所提出的 SVGED 方法能有效地实时检测水下推进器的异常情况。这为确保 AUV 的健康运行奠定了基础。

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引用次数: 0

The reliability of pre-deformation to control lateral buckling of pipelines: An evaluation based on observed embedment trends 预变形控制管道横向屈曲的可靠性：根据观察到的嵌入趋势进行评估

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-04 DOI: 10.1016/j.oceaneng.2024.119657

Jayden Chee , Phil Watson , David White , Alastair Walker

Pre-deformation of a pipeline into a continuous sinusoidal wave-like form has been shown to be effective at controlling lateral buckling of subsea pipelines due to a substantially lower axial stiffness and the limiting of maximum strain at any location. This paper explores the feasibility and reliability of using such an approach, with an existing operating pipeline, which was installed using zero-radius bend (ZRB) initiator structures, used for comparison. Survey data of the pipeline profile and seabed bathymetry are adopted along with the pipe-soil interaction (PSI) inputs from the original design allowing a like-for-like comparison of the two approaches to management of lateral buckling. The comparison shows that, for the assumptions made in the numerical modelling, use of a pre-deformed pipeline results in lower strain than using ZRBs. Furthermore, the performance of the pre-deformed pipeline is robust, and shown to be unaffected by uncertainties in horizontal out-of-straightness, PSI input and seabed features. This study shows that pre-deformed pipelines can be an effective alternative for controlling the lateral buckling of subsea pipelines, which eliminates the need for buckle initiation structures to be installed along the pipeline route. This provides impetus for further work on installation methodologies to create the required level of pre-deformation.

管道预变形为连续的正弦波状已被证明可有效控制海底管道的横向屈曲，因为其轴向刚度大大降低，并可限制任何位置的最大应变。本文探讨了使用这种方法的可行性和可靠性，并将使用零半径弯曲 (ZRB) 启动器结构安装的现有运行管道作为对比。采用管道剖面和海底水深的勘测数据以及原始设计中的管土相互作用（PSI）输入数据，对两种横向屈曲管理方法进行比较。比较结果表明，在数值建模假设条件下，使用预变形管道的应变低于使用 ZRB 的应变。此外，预变形管道的性能非常稳定，不受水平失直、PSI 输入和海底特征等不确定因素的影响。这项研究表明，预变形管道是控制海底管道横向屈曲的有效替代方案，无需在管道沿线安装屈曲引发结构。这为进一步研究安装方法以达到所需的预变形水平提供了动力。

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引用次数: 0