Ocean Engineering最新文献_第10页

Large-eddy simulation of tip clearance cavitating flow around a hydrofoil 水翼周围顶端间隙空化流的大涡流模拟

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-25 DOI: 10.1016/j.oceaneng.2024.119597

引用次数: 0

Improved FPTPPF-based predefined-time tracking control of a UVMS with actuator faults 基于 FPTPPF 的 UVMS 预定义时间跟踪控制改进型，带执行器故障

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-25 DOI: 10.1016/j.oceaneng.2024.119603

{"title":"Improved FPTPPF-based predefined-time tracking control of a UVMS with actuator faults","authors":"","doi":"10.1016/j.oceaneng.2024.119603","DOIUrl":"10.1016/j.oceaneng.2024.119603","url":null,"abstract":"<div><div>In this paper, a new predefined-time control scheme is proposed for the trajectory tracking problem of an underwater vehicle-mechanic system (UVMS) with external disturbances, model uncertainties and actuator faults. First, a predefined-time controller is proposed to achieve convergence in a predefined time so that the convergence time does not depend on the initial value of the system. Second, considering the possible grasping and transportation tasks for the UVMS, an improved flexible predefined-time prescribed performance function (FPTPPF) with self-adjustment capability is proposed to avoid the vulnerabilities of the existing prescribed performance functions. A control framework is constructed for the integral barrier Lyapunov function and FPTPPF, which can achieve good tracking performance. Third, a predefined-time extended state observer (ESO) is constructed to address the problems caused by external disturbances, model uncertainties and actuator faults. For strong sudden disturbances, the <em>H</em><sub>∞</sub> control strategy is designed via the backstepping method, which effectively improves the robustness. Finally, the predefined-time stability of the system is proven via Lyapunov stability theory, where the tracking errors can converge to a small region of the null domain in a predefined time. The performance and superiority of the proposed predefined-time control method are verified via simulation comparisons.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529597","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

Evacuation efficiency and survival rate of bent-over walking during horizontal cabin fire evacuation 水平木屋火灾疏散时弯腰行走的疏散效率和存活率

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-25 DOI: 10.1016/j.oceaneng.2024.119590

{"title":"Evacuation efficiency and survival rate of bent-over walking during horizontal cabin fire evacuation","authors":"","doi":"10.1016/j.oceaneng.2024.119590","DOIUrl":"10.1016/j.oceaneng.2024.119590","url":null,"abstract":"<div><div>Bent-over walking is a common and neglected fire evacuation behavior. To provide bent-over walking data for evacuation research, bent-over walking speed under different deck environment was obtained through experiments. In addition, to compare the differences of walking, bent-over walking and crawling in cabin fire evacuation, we used numerical simulations to test the impacts of fire location, distribution of persons at day and night, personnel evacuation to the nearest point, and directional movement on evacuation efficiency. Fire and personnel evacuation were simulated using the Fire Dynamics Simulator model. The numerical simulation results confirm that bent-over walking has a higher evacuation efficiency and survival rate as compared with walking and crawling. In addition, by comparing experimental data with the numerical simulation results, we identified a critical impact of the interaction between personnel evacuation behaviour and fire environmental factors on evacuation efficiency and mortality rate. The speed data of different evacuation behaviors obtained by the experiment is a very important factor in the study of ship evacuation, and the simulation results will provide guidance for ship fire evacuation procedures.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529431","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

Prediction of an enigmatic tsunami in October 2023 at Kii Peninsula, Japan 预测 2023 年 10 月在日本纪伊半岛发生的神秘海啸

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-24 DOI: 10.1016/j.oceaneng.2024.119623

{"title":"Prediction of an enigmatic tsunami in October 2023 at Kii Peninsula, Japan","authors":"","doi":"10.1016/j.oceaneng.2024.119623","DOIUrl":"10.1016/j.oceaneng.2024.119623","url":null,"abstract":"<div><div>On October 8, 2023, a tsunami was observed along the Pacific coast of Japan, but its cause was complicated. We applied tsunami data assimilation, a forecast method that does not consider the source, to predict coastal tsunami waveforms in the Kii Peninsula. We assimilated offshore observations recorded by pressure gauges (DONET) and reconstructed the wavefield before the tsunami arrived at the coast. The waveforms at Kumano, Kushimoto, and Shirahama were accurately forecasted at least 20 min before the tsunami arrival, indicating that data assimilation is applicable for tsunami early warning. Quantitative analysis showed that the score and accuracy index generally increased since 21:00 (UTC). Meanwhile, we investigated the tsunami decay process for tsunami warning cancellation by analysing the moving root mean squared (MRMS) amplitude. As data assimilation progressed, the prediction of tsunami later phase became increasingly accurate, and the errors between observed and predicted MRMS amplitudes decreased. Overall, the tsunami later phase was satisfactorily predicted at approximately 22:00 at coastal tide gauges. Hence, data assimilation approach contributes to a comprehensive tsunami early warning process, from the issuance to cancellation.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529667","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

Bayesian finite element model inversion of offshore wind turbine structures for joint parameter-load estimation 贝叶斯有限元模型反演海上风力涡轮机结构，用于联合参数载荷估算

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-24 DOI: 10.1016/j.oceaneng.2024.119458

{"title":"Bayesian finite element model inversion of offshore wind turbine structures for joint parameter-load estimation","authors":"","doi":"10.1016/j.oceaneng.2024.119458","DOIUrl":"10.1016/j.oceaneng.2024.119458","url":null,"abstract":"<div><div>Operating in harsh and unsteady marine environment, offshore wind turbine (OWT) structures are exposed to unpredictable wind and wave loads. Identifying the structural loads and their effects on the OWTs allow for predicting the remaining fatigue life of these structures and improving the structural design procedure. In this paper, a finite element (FE) model inversion method is presented to estimate the unknown loads and model parameters of OWTs using sparse measurement data. A realistic FE model of an OWT structure with jacket substructure is created in the open-source simulation platform, OpenSees. A Bayesian inference framework is presented to integrate the measured data with the FE model to estimate unknown wind loads and mass of rotor-nacelle assembly. To evaluate the performance of this data assimilation framework, the effect of sensor type, number of sensors, and modeling errors on the estimation accuracy of wind loads and model parameters are investigated through different case studies where synthetic data are used as measurements. The results of this study are important to guide instrumentation of new OWT structures, and to understand the potential limitations and sources of error in the real-world application of this data assimilation framework for joint model parameter and input load estimation.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529666","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

STAD: Ship trajectory anomaly detection in ocean with dynamic pattern clustering STAD：利用动态模式聚类进行海洋船舶轨迹异常检测

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-24 DOI: 10.1016/j.oceaneng.2024.119530

{"title":"STAD: Ship trajectory anomaly detection in ocean with dynamic pattern clustering","authors":"","doi":"10.1016/j.oceaneng.2024.119530","DOIUrl":"10.1016/j.oceaneng.2024.119530","url":null,"abstract":"<div><div>With the continuous increase of maritime traffic, developing an efficient and accurate model for ship trajectory anomaly detection has become crucial for ensuring maritime transportation safety. The high complexity and variability of the marine environment lead to diverse ship trajectory patterns, making it challenging to learn effective trajectory representations for accurately identifying anomalies. We thus proposed an unsupervised deep learning model called STAD for ship trajectory anomaly detection in ocean to address this challenge. Concretely, STAD leverages offset reconstruction-based representation learning and a deep Gaussian Mixture Model (GMM) estimation network to learn the underlying complex clustering patterns of ship trajectories and utilize the learned patterns to enhance trajectory anomaly detection. Extensive experiments on multiple AIS datasets indicate that our model significantly outperforms existing methods in detecting multiple representative types of ship trajectory anomalies, including shift deviation, abnormal heading, and abnormal speeding. This study could help closely monitor the status of ship movement and detect abnormal behaviors in advance, thus benefiting maritime safety.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529665","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

Impact of rogue waves on semi-submersible platforms: An experimental investigation of wave run-up and air-gap responses 流氓波对半潜式平台的影响：波浪上升和气隙反应实验研究

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-24 DOI: 10.1016/j.oceaneng.2024.119425

{"title":"Impact of rogue waves on semi-submersible platforms: An experimental investigation of wave run-up and air-gap responses","authors":"","doi":"10.1016/j.oceaneng.2024.119425","DOIUrl":"10.1016/j.oceaneng.2024.119425","url":null,"abstract":"<div><div>The wave run-up and air-gap responses of semi-submersible platforms under extreme sea conditions are crucial design considerations for ensuring the structural integrity and safety of marine engineering operations. This study investigated the impact of rogue waves on the wave run-up and air-gap responses of semi-submersible platforms using a transient focusing wave group to accurately simulate irregular seas. Comparative model tests were conducted on a semi-submersible platform under both rogue and non-rogue-wave conditions. The platform motions and air-gap responses were analysed using spectral analysis, extreme-value statistics, and wavelet methods. Rogue waves were found to significantly affect the air-gap response spectrum, increasing the nonlinearity of both the wave run-up and air-gap responses. Different locations on the platform exhibited varying statistical and spectral response characteristics. Rogue waves modified the instantaneous properties of wave elevation, thereby increasing the energy levels in the system. This study confirmed that rogue waves significantly influence the air-gap responses and wave run-up of semi-submersible platforms, suggesting that they should be considered when designing and planning the operations of these platforms. This study offers a comprehensive understanding of the complex interactions between rogue waves and large maritime structures and provides insights for improving safety and performance under extreme sea conditions.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529663","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

Prediction of mooring dynamics for a semi-submersible floating wind turbine with recurrent neural network models 利用递归神经网络模型预测半潜式浮动风力涡轮机的系泊动力学特性

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-24 DOI: 10.1016/j.oceaneng.2024.119490

{"title":"Prediction of mooring dynamics for a semi-submersible floating wind turbine with recurrent neural network models","authors":"","doi":"10.1016/j.oceaneng.2024.119490","DOIUrl":"10.1016/j.oceaneng.2024.119490","url":null,"abstract":"<div><div>Offshore wind technology emerges as a promising solution to tap into wind resources in shallow and deep waters. For floating wind turbines, mooring systems provide station-keeping functionalities. Efficient monitoring of mooring loads is critical for safe and cost-effective operation and maintenance. As direct measurement of the dynamic mooring line tension is expensive, alternative means are needed. To this end, this article focuses on predicting mooring tensions based on accessible motion data of the floating platform and proposes utilizing deep learning algorithms, i.e., recurrent neural networks (RNNs). We selected three RNN algorithms: Gated Recurrent Units (GRU), Long Short-Term Memory (LSTM), and Bidirectional LSTM (BiLSTM). These algorithms were trained with various load cases of a 10-MW floating wind turbine and their efficacy was assessed using unseen data. Among the three algorithms, the BiLSTM algorithm performed best, achieving <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> of more than 0.97 under various load conditions. Further, a statistical assessment of the tension time series demonstrates an excellent agreement between the predicted and the measured mooring line tensions with a percentage difference in the peak tension of less than 0.5%. The outcomes of this paper contribute to real-time prediction and structural health monitoring of floating wind turbines.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529664","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

Locally resonant pressure-resistant meta-shell with accordion zero Poisson's ratio core for sound insulation and sound radiation suppression 用于隔音和抑制声辐射的局部共振抗压元壳，带有风琴式零泊松比内核

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-23 DOI: 10.1016/j.oceaneng.2024.119504

{"title":"Locally resonant pressure-resistant meta-shell with accordion zero Poisson's ratio core for sound insulation and sound radiation suppression","authors":"","doi":"10.1016/j.oceaneng.2024.119504","DOIUrl":"10.1016/j.oceaneng.2024.119504","url":null,"abstract":"<div><div>The multi-functionalization of deep-sea submersibles is an important development trend of advanced marine technology, and the new shell material is one of the main design playgrounds. Recent mechanical metamaterials have the capability to prevent transverse displacements during unidirectional compression (when the Poisson's ratio is flexibly adjusted to 0) and precisely manipulate elastic/acoustic waves on a sub-wavelength scale through their inherent resonance characteristics. Therefore, the metamaterial is introduced into the shell core of underwater equipment or submersible structure, which has potential technical advantages. The pre-strain wave propagation characteristics of the considered models are obtained static and dynamic steps via the finite element method. The pressure-resistant, sound transmission and radiation properties of meta-shell sandwiched the metamaterial cores are then investigated. The results show that in comparison with a traditional zero Poisson's ratio (ZPR) honeycomb core, the proposed meta-shell with a novel ZPR metamaterial core can safely withstand hydrostatic pressures equivalent to depths of 1000 m with greater safety redundancy, while also achieving sound insulation and sound radiation suppression in the low-frequency range. This work successfully demonstrates an advanced design method for sound insulation and sound radiation suppression of shells.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529657","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 and numerical study on underwater noise control of multigrooved metasurface coating with antifouling and drag reduction potential 具有防污和减阻潜力的多槽元表面涂层的水下噪声控制实验和数值研究

IF 4.6 2区工程技术

Ocean Engineering Pub Date : 2024-10-23 DOI: 10.1016/j.oceaneng.2024.119525

{"title":"Experimental and numerical study on underwater noise control of multigrooved metasurface coating with antifouling and drag reduction potential","authors":"","doi":"10.1016/j.oceaneng.2024.119525","DOIUrl":"10.1016/j.oceaneng.2024.119525","url":null,"abstract":"<div><div>Acoustic metasurfaces have garnered increasing attention due to their efficacy in low-frequency sound absorption, while achieving broadband sound absorption performance remains challenging. In this study, a novel approach employing a multigrooved metasurface integrated onto a nanocomposite material is undertaken. Before modification, the nanocomposite material exhibits commendable underwater sound absorption capabilities above 4000 Hz, but demonstrates lower performance below this threshold. Integrating the multigrooved metasurface yields a notable enhancement in sound absorption performance below 4000 Hz, with the average absorption coefficient increasing from 0.29 to 0.63. Remarkably, this enhancement almost does not impact the performance above 4000 Hz. Experimental findings additionally reveal improved performance under variable hydrostatic pressures. Notably, the multigrooved surfaces show enhanced antifouling properties, and also exhibit potential for drag reduction compared to smooth surfaces. The proposed multigrooved metasurface in this study introduces a novel strategy towards the development of multifunctional underwater sound absorption coatings.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529659","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