Ocean Engineering最新文献_第7页

Mixed traffic conditions of autonomous and human-driven ships: Assessing channel traffic capacity bounds and optimizing channel management 自动驾驶和人工驾驶船舶的混合交通状况：评估航道通行能力边界并优化航道管理

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119734

Wenqiang Guo , Xinyu Zhang , Wen Liu , Chengbo Wang , Jingyun Wang

{"title":"Mixed traffic conditions of autonomous and human-driven ships: Assessing channel traffic capacity bounds and optimizing channel management","authors":"Wenqiang Guo , Xinyu Zhang , Wen Liu , Chengbo Wang , Jingyun Wang","doi":"10.1016/j.oceaneng.2024.119734","DOIUrl":"10.1016/j.oceaneng.2024.119734","url":null,"abstract":"<div><div>As autonomous ships (ASs) advance, mixed traffic with both autonomous and human-driven ships (HSs) will increasingly dominate seaports. Different AS penetration levels affect channel traffic capacity, potentially increasing uncertainty and risks for ships queuing to enter or exit ports. This study explores the complexities of channel traffic capacity in mixed traffic scenarios and proposes optimal management policies. A novel assessment model was proposed to quantify the relationship between AS penetration rate and the upper and lower bounds of channel traffic capacity when human crews exhibit trustful or conservative attitudes towards AS. Moreover, the total sailing duration with mixed traffic flow is analytically modeled for various possible channel allocation policies: (a) mixed channels; (b) dedicated channels; (c) mixed-ASs channels; and (d) mixed-HSs channels. Microsimulation experiments indicate that channel traffic capacity is positively correlated with ASs penetration rates. Our findings also suggest that developing an optimal channel management strategy is closely related to the penetration of AS. The optimal channel allocation strategy is the dedicated channel policy when more than 60% of ships in the mixed-HSs channel or less than 55% in the mixed-ASs channel are ASs.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119734"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660530","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 federated learning based approach for wave height prediction in maritime transportation 基于联合学习的海运波高预测方法

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119631

Prathamesh Samal, Jatin Bedi

{"title":"A federated learning based approach for wave height prediction in maritime transportation","authors":"Prathamesh Samal, Jatin Bedi","doi":"10.1016/j.oceaneng.2024.119631","DOIUrl":"10.1016/j.oceaneng.2024.119631","url":null,"abstract":"<div><div>Forecasting Ocean Wave Height (OWH) is essential for several marine operations, such as coastal and ocean engineering applications. Current state-of-the-art solutions in the domain involve building machine and deep learning-based models for estimating wave height patterns. These existing solutions lack the desired generalization capability and heavily rely on data, contextual and external features. To address these limitations, a federated learning-based approach utilizing long short-term memory (LSTM) network and Temporal Convolutional Network (TCN) for ocean wave height estimation is proposed in the current work. The experimental evaluation of the proposed solution is performed in a federated learning setting, utilizing an open-source dataset comprising eight selected National Data Buoy Center (NDBC) buoys placed in various maritime regions. The aim is to demonstrate how comparable or even better performance than individual learning may be achieved by training the individual models on decentralized time-series data and then aggregating their updates to the global model. Through experimental evaluation, the resultant prediction accuracy, generalization, and computational benefits of the proposed approach are verified compared to the existing benchmark studies.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119631"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660513","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

Influence of twisted rudder on propeller line spectrum noise and rudder control force in submarines 扭曲舵对潜艇螺旋桨线谱噪声和舵控制力的影响

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119692

Di Zhang, Jin-ming Ye, Kai Liu, Wan-li Yang

{"title":"Influence of twisted rudder on propeller line spectrum noise and rudder control force in submarines","authors":"Di Zhang, Jin-ming Ye, Kai Liu, Wan-li Yang","doi":"10.1016/j.oceaneng.2024.119692","DOIUrl":"10.1016/j.oceaneng.2024.119692","url":null,"abstract":"<div><div>As a new vibration and noise reduction measure, the twisted rudder in submarines improves propeller propulsion efficiency and reduces propeller excitation force. To fully understand the performance of the twisted rudder, the control force and propeller cavitation performance under small rudder angles were investigated. The propeller surface pressure pulsation was taken as a dipole sound source, and the low-frequency linear spectrum sound of the submarine propellers with conventional and twisted rudders under small rudder angles was numerically predicted employing an acoustic analogy method. The results showed that the twisted rudder improved the steering maneuverability and was beneficial for improving the cavitation performance of the propeller. The twisted rudder significantly reduced the main blade-passing frequency sound pressure level (1BPF SPL) of the propeller noise, which can reduce the average value of the 1BPF SPL of all monitoring points in the XY and XZ plane by more than 3.963 and 11.872 dB under different rudder angles, respectively. The results also exhibited a correlation between the reduction effect of the 1BPF SPL of the propeller and the reduction effect of the 1BPF amplitude of the unsteady force coefficient. The results have important military application value for submarine propeller noise reduction.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119692"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660408","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

Reliability analysis of DDV and SPM in BOP-based Weibull model and expand fault dataset using deep learning 利用深度学习对基于 BOP 的 Weibull 模型中的 DDV 和 SPM 进行可靠性分析并扩展故障数据集

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119670

Yang Cao, Yu Zhang, Shengnan Wu, Chen An

{"title":"Reliability analysis of DDV and SPM in BOP-based Weibull model and expand fault dataset using deep learning","authors":"Yang Cao, Yu Zhang, Shengnan Wu, Chen An","doi":"10.1016/j.oceaneng.2024.119670","DOIUrl":"10.1016/j.oceaneng.2024.119670","url":null,"abstract":"<div><div>The hydraulic systems of deepwater Blowout Preventers (BOPs) are crucial for ensuring the reliability and safety of offshore oil and gas extraction operations. A functional failure can lead to uncontrolled blowouts, resulting in casualties and significant economic losses on the rig. The Direct Drive Valve (DDV) and the Subsea Plated Mounted (SPM) valve are key components that help maintain the proper functioning of the hydraulic system in deepwater BOPs. This study begins by utilizing the Weibull analysis method to assess the reliability of the DDV and SPM valves using limited fault data samples. To enhance the accuracy of predictions, Weibull parameters are estimated through various methods, including Maximum Likelihood Estimation (MLE), Least Squares Estimation (LSE), and a combination of Correlation Coefficient Optimization with Support Vector Regression (CCO + SVR).Given the challenges in gathering extensive fault data for DDV and SPM valves—due to complex subsea environments, cost constraints, time limitations, and other factors—this study proposes a method employing a Back Propagation Neural Network (BPNN) model to augment the limited fault data samples. To ensure the reliable operation of the DDV and SPM valves, preventive maintenance cycles are established at 2840 and 7550 operations, respectively. At the same reliability level, as the number of operational cycles increases, the remaining service life of the valves gradually decreases, leading to a higher probability of failure over a shorter timeframe. The Mean Remaining Life (MRL) of the DDV and SPM valves, corresponding to different operational times, is analyzed, providing essential reference points for their usage and maintenance. When the extended data sample is utilized for reliability evaluation, the reliability characteristics of the small fault data samples are effectively reflected, and the parameter prediction error remains low. This indicates that the extended data sample is more suitable for reliability evaluation.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119670"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660402","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 study of set-up effects on axial capacity of jacked piles in saturated clay 饱和粘土中顶管桩轴向承载力的设置效应数值研究

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119709

Zihang Li , Dan Hu , Fen Li , Wenlin Xiong

{"title":"Numerical study of set-up effects on axial capacity of jacked piles in saturated clay","authors":"Zihang Li , Dan Hu , Fen Li , Wenlin Xiong","doi":"10.1016/j.oceaneng.2024.119709","DOIUrl":"10.1016/j.oceaneng.2024.119709","url":null,"abstract":"<div><div>The prediction of time-dependent behavior of axial capacity for jacked piles are essential for coastal pile engineering. This study develops a numerical model to simulate the entire process of pile installation, soil consolidation, and loading, incorporating soil-pile interaction effects on excess pore pressure and effective stress distribution in the surrounding soil, which influence the bearing performance of jacked piles in saturated clay. The well consistency between the predictions from the presented approach and the experimental measurement data validate the applicability of the proposed model. The mechanism of set-up effects on the pile axial capacity is elucidated through the evolution of excess pore pressure. A parametric study is performed to assess the influence of the permeability coefficient (<em>k</em>) and length-to-diameter (<em>L</em>/<em>D</em><sub>e</sub>) ratio on the axial capacity of jacked piles. The findings demonstrate that the proposed model accurately predicts the set-up effects of jacked piles. Specifically, the permeability coefficient primarily impacts the rate of capacity increase, while the axial capacity exhibits a significant rise with an increase in <em>L</em>/<em>D</em><sub>e</sub>. The derived empirical formula can reasonably guide the design of the axial bearing capacity of piles in saturated clay.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119709"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660405","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

Wave scattering by multiple floating flexible circular plates over a porous bed 多孔床面多块漂浮柔性圆板的波散射

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119663

A.K. Kushwaha , V.K. Gupta , H. Behera , T.-W. Hsu

{"title":"Wave scattering by multiple floating flexible circular plates over a porous bed","authors":"A.K. Kushwaha , V.K. Gupta , H. Behera , T.-W. Hsu","doi":"10.1016/j.oceaneng.2024.119663","DOIUrl":"10.1016/j.oceaneng.2024.119663","url":null,"abstract":"<div><div>This study develops a theoretical model to analyze wave scattering between multiple floating flexible circular plates and water waves propagating over a porous bed. This boundary value problem is tackled using the eigenfunction expansion technique along with Graf’s addition theorem. Utilizing the relevant boundary conditions, the unknown velocity potentials for the outer area and the plate-covered regions are determined. In each region of the problem domain, the velocity potentials associated with the incident and scattered waves are expressed through an expansion utilizing Bessel and Hankel functions. The study incorporates three distinct edge boundary conditions: clamped, moored, and free. The effectiveness of this study in evaluating the influence of various parameters is assessed by analyzing the heave force acting on the circular plates. This study reveals a compelling trend: as the porous-effect parameter associated with the porous bottom increases, the heave force exerted on the circular plates exhibits a significant reduction. It is also observed that for an array of two, three, and four circular flexible plates, the heave force on each subsequent plate is reduced compared to the preceding plates. Furthermore, to clearly visualize the wave dynamics around the circular flexible plates over time, a time simulation of the fluid flow is provided for different porosity parameter values. This simulation shows a reduced wave amplitude in the lee-side zone. The flow distributions around the circular plates are illustrated both with and without single or multiple circular plates, indicating a lower amplitude in the lee-side zone. The porous bed significantly contributes to diminishing the wave force exerted on the circular plates and establishing a calm area on the back side of the structures.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119663"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660512","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

Hydroelasticity of a 21000TEU containership under freak waves by fluid-flexible structure interaction simulations 通过流体-柔性结构相互作用模拟 21000TEU 集装箱船在巨浪下的水弹性

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119748

Bowen Ma , Xing Chang , Zhenwei Chen , Jialong Jiao

引用次数: 0

Comparative study of seismic response of offshore tetrapod jacket systems with semi-rigid and flexible piles under environmental loads 带半刚性桩和柔性桩的近海四柱护套系统在环境荷载作用下的地震响应对比研究

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119716

Yikang Wang , Chen Wang , Hao Zhang , Fayun Liang , Zhouchi Yuan

{"title":"Comparative study of seismic response of offshore tetrapod jacket systems with semi-rigid and flexible piles under environmental loads","authors":"Yikang Wang , Chen Wang , Hao Zhang , Fayun Liang , Zhouchi Yuan","doi":"10.1016/j.oceaneng.2024.119716","DOIUrl":"10.1016/j.oceaneng.2024.119716","url":null,"abstract":"<div><div>Tetrapod piled jacket (TPJ) foundations, featuring large-diameter semi-rigid piles have been employed to support offshore wind turbines (OWTs), but limited research exists on their dynamic response under seismic excitations in marine environments. Thus, this study employs advanced 3D finite element simulations to analyze and compare the seismic responses of flexible and semi-rigid piled TPJ systems under combined dynamic loads. Under seismic loads, the semi-rigid piled system experience higher compressive stress on the tower but lower maximum stress at X-brace and battered leg joints compared to flexible piled systems. Additionally, soil shear strain in the semi-rigid pile system displays a punch-through failure pattern at the pile end. The impacts of increasing scour depth and clay shear strength on semi-rigid-piled systems are distinctly characterized by greater pile top settlement, augmented bending moment responses, and diminished rotational deformation, compared to those of flexible ones. These findings offer valuable insights into semi-rigid-piled TPJ system dynamic response in complex marine environments.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119716"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660543","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

Performance enhancement of floating raft system by exploiting geometric nonlinearity and motion constraint in vibration isolators 利用隔振器的几何非线性和运动约束增强浮筏系统的性能

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119656

Wei Dai , Tianyun Li , Lin Wang , Xiang Zhu , Baiyang Shi , Jian Yang

{"title":"Performance enhancement of floating raft system by exploiting geometric nonlinearity and motion constraint in vibration isolators","authors":"Wei Dai , Tianyun Li , Lin Wang , Xiang Zhu , Baiyang Shi , Jian Yang","doi":"10.1016/j.oceaneng.2024.119656","DOIUrl":"10.1016/j.oceaneng.2024.119656","url":null,"abstract":"<div><div>This paper proposes a nonlinear vibration isolator with hybrid passive elements to mitigate the vibration transmission in floating raft systems. The proposed isolator employs a combination of a geometrically nonlinear linkage mechanism, an inerter, and a motion constraint. Analytical and numerical methods are applied to determine the responses. Given the presence of multiple transmission paths and excitations, power flow indices serve as primary metrics for performance assessment. The results show that the constraint can prevent the folding problem of the linkage mechanism. This, in turn, provides 1) flexibility in the parameter design to achieve quasi-zero dynamic stiffness and 2) protection for geometrically nonlinear systems under extreme operating conditions. The proposed element introduces an anti-peak into the response and power transmission curves, effectively shifting the resonance peaks to lower frequencies. The desired low-frequency isolation performance can be achieved through a coordinated parameter design. This would provide an ultralow response as well as force and energy transmission near the original resonant peaks of the linear system. Furthermore, the proposed design exhibits enhanced performance across diverse operational conditions including multiple frequency excitations and varying mass ratios and forcing amplitudes. These observations demonstrate the potential of utilizing hybrid nonlinear elements in ocean engineering applications.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119656"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660528","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

Experimental and analytical assessment of the bending behaviour of floating inflated membrane beams 浮动充气膜梁弯曲性能的实验和分析评估

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119710

Yunling Ye , Jin Gan , Weiguo Wu , Shan Wang , C. Guedes Soares

{"title":"Experimental and analytical assessment of the bending behaviour of floating inflated membrane beams","authors":"Yunling Ye , Jin Gan , Weiguo Wu , Shan Wang , C. Guedes Soares","doi":"10.1016/j.oceaneng.2024.119710","DOIUrl":"10.1016/j.oceaneng.2024.119710","url":null,"abstract":"<div><div>The study aims to study the bending and failure behaviour of the inflated membrane beams under floating conditions to support their application in floating platforms. Bending tests are conducted to assess the structural stiffness and ultimate bearing capacity of the beam with various diameters and inflated pressures. With the elastic modulus determined through four-point bending tests, a new analytical formula based on Winkler elastic foundation theory is then developed to predict the deflection of the beams. The results revealed that the beams initially undergo total submersion, followed by end turn-up and anti-arching deformation in the loaded section. The bearing capacity of the beams increases with the increase in internal pressure and diameter. Localised wrinkling is a typical failure mode at low internal pressures, while at high pressures, the failure mode shifts to boundary failure, characterised by submerging in water. The experimental and analytical results show quite good agreement, confirming the accuracy of the current analysis. Overall, this paper contributes to understanding the bending and failure behaviour of inflated membrane beams under floating conditions and supports the offshore structure safety design.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119710"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660529","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