Applied Ocean Research最新文献

Toward an AI-enhanced hydro-morphodynamic model for nature-based solutions in coastal erosion mitigation 建立人工智能增强型水文形态动力学模型，为减缓海岸侵蚀提供基于自然的解决方案

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-17 DOI: 10.1016/j.apor.2024.104326

Nour Dammak, Wei Chen, Joanna Staneva

In the application of sustainable Nature-based Solution (NbS) for coastal engineering, a significant challenge lies in determining the effectiveness of these NbS approaches in mitigating coastal erosion. The efficacy of NbS is influenced by various factors, including the specific location, layout, and the scale of implementation. This study integrates artificial intelligence (AI) with hydro-morphodynamic numerical simulations to develop an AI-based emulator focused on predicting Bed Level Changes (BLC) as indicators of erosion and deposition dynamics. Specifically, we explore the influence of seagrass meadows, varying in starting depth (hs) and depth range (hr), on coastal erosion mitigation during storm events.

The framework leverages a hybrid approach combining the SCHISM-WWM hydrodynamic model with XBeach for simulating 180 depth range and starting depth combination (h_r-h_s) scenarios along the Norderney coast in the German Bight. A Convolutional Neural Network (CNN) architecture is employed with dual inputs—roller energy and Eulerian velocity—to predict BLC efficiently. The CNN demonstrates high accuracy in replicating spatial erosion patterns and quantifying erosion volumes, achieving an RMSE of 3.47 cm and an R² of 0.94 during validation.

This innovative integration of AI and NbS not only reduces computational costs associated with traditional numerical modelling but also enhances the feasibility of What-if Scenarios applications for coastal erosion management. The findings underscore the potential of AI-driven approaches to optimize seagrass transplantation layouts and inform sustainable coastal protection strategies effectively. Future advancements aim to further streamline model integration and scalability, thereby advancing NbS applications in enhancing coastal resilience against environmental stressors.

在将可持续的 "基于自然的解决方案"（NbS）应用于海岸工程的过程中，面临的一个重大挑战是如何确定这些 NbS 方法在减缓海岸侵蚀方面的有效性。NbS 的效果受到各种因素的影响，包括具体位置、布局和实施规模。本研究将人工智能（AI）与水文形态动力学数值模拟相结合，开发了一个基于人工智能的模拟器，重点预测作为侵蚀和沉积动态指标的床面变化（BLC）。具体而言，我们探索了海草草甸在起始深度（hs）和深度范围（hr）上的变化对风暴事件期间海岸侵蚀减缓的影响。该框架采用了一种混合方法，将 SCHISM-WWM 流体动力模型与 XBeach 相结合，模拟了德国湾 Norderney 海岸沿线的 180 个深度范围和起始深度组合（hr-hs）情景。采用卷积神经网络（CNN）架构，利用双重输入--滚筒能量和欧拉速度--有效预测 BLC。该 CNN 在复制空间侵蚀模式和量化侵蚀量方面表现出很高的准确性，在验证过程中实现了 3.47 厘米的 RMSE 和 0.94 的 R² 。研究结果凸显了人工智能驱动方法在优化海草移植布局和有效告知可持续海岸保护战略方面的潜力。未来的发展目标是进一步简化模型集成和可扩展性，从而推动 NbS 应用于提高沿海地区抵御环境压力的能力。

{"title":"Toward an AI-enhanced hydro-morphodynamic model for nature-based solutions in coastal erosion mitigation","authors":"Nour Dammak, Wei Chen, Joanna Staneva","doi":"10.1016/j.apor.2024.104326","DOIUrl":"10.1016/j.apor.2024.104326","url":null,"abstract":"<div><div>In the application of sustainable Nature-based Solution (NbS) for coastal engineering, a significant challenge lies in determining the effectiveness of these NbS approaches in mitigating coastal erosion. The efficacy of NbS is influenced by various factors, including the specific location, layout, and the scale of implementation. This study integrates artificial intelligence (AI) with hydro-morphodynamic numerical simulations to develop an AI-based emulator focused on predicting Bed Level Changes (BLC) as indicators of erosion and deposition dynamics. Specifically, we explore the influence of seagrass meadows, varying in starting depth (hs) and depth range (hr), on coastal erosion mitigation during storm events.</div><div>The framework leverages a hybrid approach combining the SCHISM-WWM hydrodynamic model with XBeach for simulating 180 depth range and starting depth combination (h<sub>r</sub>-h<sub>s</sub>) scenarios along the Norderney coast in the German Bight. A Convolutional Neural Network (CNN) architecture is employed with dual inputs—roller energy and Eulerian velocity—to predict BLC efficiently. The CNN demonstrates high accuracy in replicating spatial erosion patterns and quantifying erosion volumes, achieving an RMSE of 3.47 cm and an R² of 0.94 during validation.</div><div>This innovative integration of AI and NbS not only reduces computational costs associated with traditional numerical modelling but also enhances the feasibility of What-if Scenarios applications for coastal erosion management. The findings underscore the potential of AI-driven approaches to optimize seagrass transplantation layouts and inform sustainable coastal protection strategies effectively. Future advancements aim to further streamline model integration and scalability, thereby advancing NbS applications in enhancing coastal resilience against environmental stressors.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104326"},"PeriodicalIF":4.3,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656156","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

Development of Spatial Clustering Method and Probabilistic Prediction Model for Maritime Accidents 海上事故空间聚类方法和概率预测模型的开发

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-16 DOI: 10.1016/j.apor.2024.104317

Cheol-Won Choe , Suhwan Lim , Dong Jun Kim , Ho-Chul Park

Maritime accidents are complex incidents characterized by the absence of physically defined routes, unlike roads, and influenced by various factors such as marine conditions, vessel status, and multiple contributing factors. Despite efforts to reduce maritime accidents in Republic of Korea, the number of accident occurrences remains at a high level. Moreover, the infrequency of severe accidents makes it difficult to gather sufficient data for comprehensive analysis. This study aims to construct and validate a maritime accident prediction model to protect life and property in the event of accidents, considering the characteristics of the ocean, where tracking and managing transportation means is challenging. For the first step of predicting maritime accidents, a 5-level spatial system was constructed based on the density of accidents and vessel traffic. The data to be used in the analysis was constructed through four steps. In order to evaluate the maritime accident prediction model, we conducted a comparative analysis with the machine learning-based ANN model using a Confusion matrix. Cost-of-omission analyses were conducted based on vessel traffic volume and environmental factors according to the seasons to examine the influence of variables on the probability of maritime accidents. Based on this, implications are presented through an analysis of the causes of maritime accidents according to their factors.

海上事故是一种复杂的事故，其特点是与道路不同，没有实际确定的路线，并受到海洋条件、船舶状态和多种诱因等各种因素的影响。尽管大韩民国努力减少海上事故，但事故发生的数量仍然居高不下。此外，由于严重事故的发生频率较低，因此很难收集到足够的数据进行综合分析。本研究旨在构建和验证一个海上事故预测模型，以便在发生事故时保护生命和财产安全，同时考虑到海洋的特点，因为在海洋中跟踪和管理运输工具具有挑战性。在预测海上事故的第一步，研究人员根据事故密度和船舶流量构建了一个五级空间系统。用于分析的数据通过四个步骤构建。为了评估海上事故预测模型，我们使用混淆矩阵与基于机器学习的 ANN 模型进行了比较分析。我们根据船舶交通量和季节环境因素进行了排放成本分析，以研究变量对海上事故发生概率的影响。在此基础上，根据海上事故的因素分析了事故原因，并提出了相应的影响。

{"title":"Development of Spatial Clustering Method and Probabilistic Prediction Model for Maritime Accidents","authors":"Cheol-Won Choe , Suhwan Lim , Dong Jun Kim , Ho-Chul Park","doi":"10.1016/j.apor.2024.104317","DOIUrl":"10.1016/j.apor.2024.104317","url":null,"abstract":"<div><div>Maritime accidents are complex incidents characterized by the absence of physically defined routes, unlike roads, and influenced by various factors such as marine conditions, vessel status, and multiple contributing factors. Despite efforts to reduce maritime accidents in Republic of Korea, the number of accident occurrences remains at a high level. Moreover, the infrequency of severe accidents makes it difficult to gather sufficient data for comprehensive analysis. This study aims to construct and validate a maritime accident prediction model to protect life and property in the event of accidents, considering the characteristics of the ocean, where tracking and managing transportation means is challenging. For the first step of predicting maritime accidents, a 5-level spatial system was constructed based on the density of accidents and vessel traffic. The data to be used in the analysis was constructed through four steps. In order to evaluate the maritime accident prediction model, we conducted a comparative analysis with the machine learning-based ANN model using a Confusion matrix. Cost-of-omission analyses were conducted based on vessel traffic volume and environmental factors according to the seasons to examine the influence of variables on the probability of maritime accidents. Based on this, implications are presented through an analysis of the causes of maritime accidents according to their factors.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104317"},"PeriodicalIF":4.3,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656155","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

Investigation on dynamic response of J-tube submarine cable around monopile foundation 单桩基础周围 J 型管海底电缆动态响应研究

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-16 DOI: 10.1016/j.apor.2024.104319

Peiyuan Zhou , Yangyang Gao , Lizhong Wang , Lingling Li

A series of numerical simulations are performed to investigate the dynamic response of J-tube submarine cable around monopile foundation. The variations of maximum curvature, maximum effective tension and motion amplitude with incident angle, significant wave height, current velocity and suspended length are analyzed. The results show that as the significant wave height and current velocity increase, the maximum curvatures at both ends of submarine cable increase. Moreover, the maximum curvature and effective tension significantly increase with the increase of suspended length. Different protection methods for the J-tube submarine cable are investigated to reduce the risks of curvature and bending failures. It is found that the riprap-concrete mattress combined protection can effectively reduce the maximum curvature and motion amplitude of J-tube submarine cable.

对单桩地基周围 J 型管海底电缆的动态响应进行了一系列数值模拟研究。分析了最大曲率、最大有效张力和运动振幅随入射角、显著波高、流速和悬挂长度的变化。结果表明，随着显波高度和流速的增加，海缆两端的最大曲率也随之增加。此外，随着悬挂长度的增加，最大曲率和有效张力也明显增加。研究了 J 型管海缆的不同保护方法，以降低曲率和弯曲故障的风险。研究发现，护坡-混凝土褥垫组合保护可有效降低 J 型管海底电缆的最大曲率和运动幅度。

引用次数: 0

Active control of vibration and radiated noise in the shaft-shell coupled system of an underwater vehicle 主动控制水下航行器轴壳耦合系统的振动和辐射噪声

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-16 DOI: 10.1016/j.apor.2024.104324

Yaqi Tian , Cong Zhang , Lei Yang

Active control is effective in reducing the low-frequency vibration and acoustic radiation of the stern system of an underwater vehicle. This paper theoretically investigates the reduction of vibration and far-field radiation noise in the stern system of an underwater vehicle arising from propeller bearing forces and surface force excitations. Based on the Flügge theory and Euler–Bernoulli theory, an analytical dynamic model of the shaft-shell system is established. The effectiveness of the analytical model is verified through finite element and boundary element methods. The impact of actuator placement, error signal selection, and control strategies on the effectiveness of active control is discussed. A combined active control scheme for the shaft-shell system, involving electromagnetic actuators installed on both the shaft and the shell, is proposed. This scheme effectively controls shaft vibration, shell vibration, and far-field acoustic radiation simultaneously. The theoretical model established in this paper can be used as a reference for low-frequency vibration control of an underwater vehicle.

主动控制可有效降低水下航行器船尾系统的低频振动和声辐射。本文从理论上研究了如何减少螺旋桨轴承力和表面力激振所产生的水下航行器艉轴系统的振动和远场辐射噪声。以 Flügge 理论和 Euler-Bernoulli 理论为基础，建立了轴壳系统的分析动力学模型。通过有限元和边界元方法验证了分析模型的有效性。讨论了致动器位置、误差信号选择和控制策略对主动控制效果的影响。提出了一种轴壳系统组合主动控制方案，涉及安装在轴和壳上的电磁致动器。该方案可同时有效控制轴振动、壳振动和远场声辐射。本文建立的理论模型可作为水下航行器低频振动控制的参考。

{"title":"Active control of vibration and radiated noise in the shaft-shell coupled system of an underwater vehicle","authors":"Yaqi Tian , Cong Zhang , Lei Yang","doi":"10.1016/j.apor.2024.104324","DOIUrl":"10.1016/j.apor.2024.104324","url":null,"abstract":"<div><div>Active control is effective in reducing the low-frequency vibration and acoustic radiation of the stern system of an underwater vehicle. This paper theoretically investigates the reduction of vibration and far-field radiation noise in the stern system of an underwater vehicle arising from propeller bearing forces and surface force excitations. Based on the Flügge theory and Euler–Bernoulli theory, an analytical dynamic model of the shaft-shell system is established. The effectiveness of the analytical model is verified through finite element and boundary element methods. The impact of actuator placement, error signal selection, and control strategies on the effectiveness of active control is discussed. A combined active control scheme for the shaft-shell system, involving electromagnetic actuators installed on both the shaft and the shell, is proposed. This scheme effectively controls shaft vibration, shell vibration, and far-field acoustic radiation simultaneously. The theoretical model established in this paper can be used as a reference for low-frequency vibration control of an underwater vehicle.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104324"},"PeriodicalIF":4.3,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656217","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 observation on violent sloshing flows inside rectangular tank with flexible baffles 带柔性挡板的矩形水槽内剧烈荡流的实验观测

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-14 DOI: 10.1016/j.apor.2024.104307

Taehyun Park , Cheon-Jin Park , Jeoungkyu Lee , Yonghwan Kim

In this study, a series of sloshing model tests were conducted to observe the effects of an internal baffle in a rectangular tank and to secure basic data for future numerical calculations or applications to similar phenomena.

The sloshing flows and flexible motions of two different baffles with hyper-elastic properties were observed and the results were compared with those of a non-flexible baffle. Experiments were conducted for different filling conditions, motion amplitudes, and excitation frequencies, with a particular focus on violent flow cases. The local flows around the baffles were captured using a high-speed camera, and the sloshing-induced impact pressures on the tank walls were measured. The present experiment showed strong interactions between flexible baffle motion and sloshing flows, particularly at motion frequencies higher than the natural sloshing frequency. The physical phenomena became more complicated when the free surface was closer to the baffle height. The data obtained in this study can be used as benchmark tests for numerical computation of strong-fluid interactions.

在本研究中，进行了一系列荡流模型试验，以观察矩形水箱中内部挡板的影响，并为将来的数值计算或类似现象的应用获取基础数据。实验针对不同的填充条件、运动幅度和激振频率进行，尤其侧重于剧烈流动的情况。使用高速摄像机捕捉了挡板周围的局部流动，并测量了湍流对罐壁造成的冲击压力。本实验表明，柔性挡板运动与荡流间存在强烈的相互作用，尤其是在运动频率高于自然荡流频率时。当自由表面更接近障板高度时，物理现象变得更加复杂。本研究获得的数据可作为强流体相互作用数值计算的基准测试。

{"title":"Experimental observation on violent sloshing flows inside rectangular tank with flexible baffles","authors":"Taehyun Park , Cheon-Jin Park , Jeoungkyu Lee , Yonghwan Kim","doi":"10.1016/j.apor.2024.104307","DOIUrl":"10.1016/j.apor.2024.104307","url":null,"abstract":"<div><div>In this study, a series of sloshing model tests were conducted to observe the effects of an internal baffle in a rectangular tank and to secure basic data for future numerical calculations or applications to similar phenomena.</div><div>The sloshing flows and flexible motions of two different baffles with hyper-elastic properties were observed and the results were compared with those of a non-flexible baffle. Experiments were conducted for different filling conditions, motion amplitudes, and excitation frequencies, with a particular focus on violent flow cases. The local flows around the baffles were captured using a high-speed camera, and the sloshing-induced impact pressures on the tank walls were measured. The present experiment showed strong interactions between flexible baffle motion and sloshing flows, particularly at motion frequencies higher than the natural sloshing frequency. The physical phenomena became more complicated when the free surface was closer to the baffle height. The data obtained in this study can be used as benchmark tests for numerical computation of strong-fluid interactions.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104307"},"PeriodicalIF":4.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656212","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

Study on critical condition of damage mode of local grillage structure under near-field underwater explosion 近场水下爆炸下局部格栅结构破坏模式临界状态研究

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-14 DOI: 10.1016/j.apor.2024.104313

Kun Zhao , Dongyan Shi , Zhikai Wang , Yanpei Zhou , Yonghui Liang

The rapid prediction of damage to underwater explosion-damaged ship plate structures is a crucial element in the assessment of ship impact damage. In this paper, we address the challenge of rapidly predicting the damage mode of plate and frame structures subjected to underwater explosions. We begin by establishing that the shock wave load of an underwater explosion can be modeled as a rectangular pulse, based on the effective impulse of action and the characteristics of the target structure. We then delve into the mechanical criteria governing the different damage modes, employing the equivalent theory of plate and frame. The critical condition of the dimensionless damage mode of the local plate and frame structure of the ship is deduced by the dimensional analysis method based on the mechanical criterion of damage mode. In this paper, an integrated approach combining experimental and numerical research methods is employed. Firstly, an analysis of the damage modes of the light plate structure is conducted. The experimental data, numerical data, and theoretical calculation data based on the critical discriminant condition of the dimensionless damage mode are compared. The accuracy and reliability of the numerical method and the critical discriminant condition of the dimensionless damage mode are validated. A series of numerical simulations were conducted on the plate and stiffened plate structure of a ship, and the validity of the critical discriminant conditions of the dimensionless damage mode is confirmed. In conjunction with the underwater explosion impact factor, an engineering estimation method for the damage of the local plate structure of the ship is developed ultimately.

快速预测水下爆炸损坏的船板结构的损坏情况是评估船舶撞击损坏情况的关键因素。在本文中，我们要解决的难题是快速预测遭受水下爆炸的板状和框架结构的损坏模式。首先，我们根据有效作用冲力和目标结构的特征，确定水下爆炸的冲击波载荷可模拟为矩形脉冲。然后，我们利用板和框架的等效理论，深入研究了支配不同破坏模式的力学标准。根据损伤模式的力学准则，通过尺寸分析方法推导出船舶局部板框结构无量纲损伤模式的临界条件。本文采用了实验和数值研究相结合的综合方法。首先，对轻质板结构的损伤模式进行了分析。比较了实验数据、数值数据和基于无量纲损伤模式临界判别条件的理论计算数据。验证了数值方法和无量纲损伤模式临界判别条件的准确性和可靠性。对船舶的板和加劲板结构进行了一系列数值模拟，证实了无量纲破坏模式临界判别条件的有效性。结合水下爆炸影响因子，最终开发出一种船舶局部板结构损伤的工程估算方法。

{"title":"Study on critical condition of damage mode of local grillage structure under near-field underwater explosion","authors":"Kun Zhao , Dongyan Shi , Zhikai Wang , Yanpei Zhou , Yonghui Liang","doi":"10.1016/j.apor.2024.104313","DOIUrl":"10.1016/j.apor.2024.104313","url":null,"abstract":"<div><div>The rapid prediction of damage to underwater explosion-damaged ship plate structures is a crucial element in the assessment of ship impact damage. In this paper, we address the challenge of rapidly predicting the damage mode of plate and frame structures subjected to underwater explosions. We begin by establishing that the shock wave load of an underwater explosion can be modeled as a rectangular pulse, based on the effective impulse of action and the characteristics of the target structure. We then delve into the mechanical criteria governing the different damage modes, employing the equivalent theory of plate and frame. The critical condition of the dimensionless damage mode of the local plate and frame structure of the ship is deduced by the dimensional analysis method based on the mechanical criterion of damage mode. In this paper, an integrated approach combining experimental and numerical research methods is employed. Firstly, an analysis of the damage modes of the light plate structure is conducted. The experimental data, numerical data, and theoretical calculation data based on the critical discriminant condition of the dimensionless damage mode are compared. The accuracy and reliability of the numerical method and the critical discriminant condition of the dimensionless damage mode are validated. A series of numerical simulations were conducted on the plate and stiffened plate structure of a ship, and the validity of the critical discriminant conditions of the dimensionless damage mode is confirmed. In conjunction with the underwater explosion impact factor, an engineering estimation method for the damage of the local plate structure of the ship is developed ultimately.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"153 ","pages":"Article 104313"},"PeriodicalIF":4.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659166","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

Comprehensive feature-based machine learning for fast prediction of marine propeller's open-water performance 基于特征的综合机器学习可快速预测船用螺旋桨的开放水域性能

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-14 DOI: 10.1016/j.apor.2024.104310

Liang Li , Yihong Chen , Shuo Xie , Yucheng Xiao , Tian Fang , Chao Wang

To address the strong demand for the efficient iterative design of marine propellers, this study researched a rapid prediction surrogate model for propeller open-water performance using a dataset comprising 1980 propeller open-water performance test results. A dimension reduction method based on comprehensive features is proposed, and eight input parameters were determined through correlation and importance analysis. Five machine learning algorithms were utilized to construct the prediction surrogate model employing the Grid Search combined with K-fold Cross-Validation. The validation results indicate that the SVR model performed the best on the validation set, with errors in predicting K_T,10K_Q, and η within 2 %. Further validation was conducted on three unseen propellers in the test set and two new design propeller schemes. It is found that the SVR model, based on comprehensive features, demonstrated good accuracy for the open-water performance prediction of unseen propeller schemes, with errors within 4 %. Compared with the CFD method, the computational performance of the SVR model is approximately 1000 times faster. Additionally, it effectively identifies load variations resulting from overall or local adjustments in pitch distribution, providing new means for rapid performance prediction and optimization design of marine propellers.

为满足船用螺旋桨高效迭代设计的强烈需求，本研究利用由 1980 个螺旋桨公开水域性能测试结果组成的数据集，研究了螺旋桨公开水域性能快速预测代用模型。研究提出了一种基于综合特征的降维方法，并通过相关性和重要性分析确定了八个输入参数。采用网格搜索结合 K 倍交叉验证的方法，利用五种机器学习算法构建了预测代用模型。验证结果表明，SVR 模型在验证集上表现最佳，预测 KT、10KQ 和 η 的误差在 2% 以内。对测试集中的三个未见螺旋桨和两个新设计的螺旋桨方案进行了进一步验证。结果发现，基于综合特征的 SVR 模型对未见螺旋桨方案的开放水域性能预测具有良好的准确性，误差在 4% 以内。与 CFD 方法相比，SVR 模型的计算性能提高了约 1000 倍。此外，它还能有效识别桨距分布的整体或局部调整导致的载荷变化，为船用螺旋桨的快速性能预测和优化设计提供了新的手段。

{"title":"Comprehensive feature-based machine learning for fast prediction of marine propeller's open-water performance","authors":"Liang Li , Yihong Chen , Shuo Xie , Yucheng Xiao , Tian Fang , Chao Wang","doi":"10.1016/j.apor.2024.104310","DOIUrl":"10.1016/j.apor.2024.104310","url":null,"abstract":"<div><div>To address the strong demand for the efficient iterative design of marine propellers, this study researched a rapid prediction surrogate model for propeller open-water performance using a dataset comprising 1980 propeller open-water performance test results. A dimension reduction method based on comprehensive features is proposed, and eight input parameters were determined through correlation and importance analysis. Five machine learning algorithms were utilized to construct the prediction surrogate model employing the Grid Search combined with K-fold Cross-Validation. The validation results indicate that the SVR model performed the best on the validation set, with errors in predicting <em>K<sub>T</sub></em>,10<em>K<sub>Q,</sub></em> and <em>η</em> within 2 %. Further validation was conducted on three unseen propellers in the test set and two new design propeller schemes. It is found that the SVR model, based on comprehensive features, demonstrated good accuracy for the open-water performance prediction of unseen propeller schemes, with errors within 4 %. Compared with the CFD method, the computational performance of the SVR model is approximately 1000 times faster<em>.</em> Additionally, it effectively identifies load variations resulting from overall or local adjustments in pitch distribution, providing new means for rapid performance prediction and optimization design of marine propellers.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104310"},"PeriodicalIF":4.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656216","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 Sediment Suspension over the Liquefied Sand-clay Seabed under Waves 波浪作用下液化砂粘土海底沉积物悬浮实验研究

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-14 DOI: 10.1016/j.apor.2024.104314

Jun Zhang , Lizhu Wang , Zhiyong Zhang , Yihao Sun

The characteristics of erosion and sediment suspension over the wave-induced liquefied mixed seabed are investigated experimentally in this study, as well as the mechanism underlying the phenomena. The mixed beds with various Clay Content (CC) ranging from 0 to 9.9 % were tested under a specific wave condition. The erosion depth of beds, Excess Pore water Pressure (EPP), and Suspended Sediment Concentration (SSC) are measured and analyzed at different liquefaction stages, and their relationships with CC are emphatically discussed. The results show that the erosion depth and SSC vary non-linearly with CC. The cohesive beds with 0.5 % and 1 % CC erode more significantly than the cohesionless sand bed. The erosion depth and SSC of mixed beds with >1 % CC, decrease with the increase of CC. The accumulated EPP significantly reduces the critical shear stress of the beds through the seepage force, while the cohesive force from the clay content increases it, leading to the complicated phenomena of mixed seabed under wave actions.

本研究通过实验研究了波浪诱发液化混合海床的侵蚀和沉积物悬浮特征，以及这些现象的内在机理。在特定的波浪条件下，对不同粘土含量（CC）（0-9.9%）的混合海床进行了测试。对不同液化阶段的床面侵蚀深度、过剩孔隙水压力（EPP）和悬浮泥沙浓度（SSC）进行了测量和分析，并重点讨论了它们与 CC 的关系。结果表明，侵蚀深度和 SSC 与 CC 呈非线性变化。与无粘性砂床相比，CC 含量为 0.5 % 和 1 % 的粘性砂床的侵蚀更为明显。含 1 % CC 的混床的侵蚀深度和 SSC 随 CC 的增加而减小。累积的 EPP 通过渗流力大大降低了海床的临界剪应力，而粘土含量产生的内聚力则增加了临界剪应力，从而导致了波浪作用下混合海床的复杂现象。

引用次数: 0

Triaxial test on load-bear capacity of the vibro-compaction coral sand foundation in the South China Sea 南海振冲夯实珊瑚砂地基承载力的三轴试验

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-13 DOI: 10.1016/j.apor.2024.104321

Ru Qu , Chenghao Ma , Haifeng Liu , Changqi Zhu , Tao Hu

Vibro-compaction is the main improvement method for hydraulic reclamation coral sand sites. Currently, the load-bearing characteristics of coral sand composite foundation reinforced by vibro-compaction have not been clarified. This paper investigates strength characteristics of coral sand composite samples (core and shell) by artificially preparing radial variable-density coral sand composite samples and performing consolidated drained triaxial tests under different area replacement rates, core-shell density ratios, and confining pressures. The results of the study show that the contribution of the core gradually increases with the increasing area replacement rate. The peak strength and peak friction angle of samples also increase gradually, but the growth tendency gradually slows down. The stress concentration coefficient of sample core is variable and follows a development pattern of first increasing and then decreasing. The secant Young's modulus of composite samples increases in a power function type with the increase of area replacement rate. The particle breakage of samples is mainly the rupture and abrasion of the 0.5–1 mm and 0.1–0.25 mm particle groups that serve as fillers. The research results can provide technical support for coral reef engineering construction.

振动压实是水力填海珊瑚砂场地的主要改进方法。目前，振捣加固珊瑚砂复合地基的承载特性尚未明确。本文通过人工制备径向变密度珊瑚砂复合材料样品，并在不同面积置换率、芯壳密度比和约束压力下进行固结排水三轴试验，研究了珊瑚砂复合材料样品（芯壳）的强度特性。研究结果表明，随着面积置换率的增加，砂芯的贡献逐渐增大。样品的峰值强度和峰值摩擦角也逐渐增加，但增长趋势逐渐放缓。试样芯部的应力集中系数是可变的，遵循先增大后减小的发展规律。复合材料样品的杨氏模量随面积置换率的增加而呈幂函数型增长。样品的颗粒破损主要是作为填料的 0.5-1 毫米和 0.1-0.25 毫米颗粒组的破裂和磨损。该研究成果可为珊瑚礁工程建设提供技术支持。

{"title":"Triaxial test on load-bear capacity of the vibro-compaction coral sand foundation in the South China Sea","authors":"Ru Qu , Chenghao Ma , Haifeng Liu , Changqi Zhu , Tao Hu","doi":"10.1016/j.apor.2024.104321","DOIUrl":"10.1016/j.apor.2024.104321","url":null,"abstract":"<div><div>Vibro-compaction is the main improvement method for hydraulic reclamation coral sand sites. Currently, the load-bearing characteristics of coral sand composite foundation reinforced by vibro-compaction have not been clarified. This paper investigates strength characteristics of coral sand composite samples (core and shell) by artificially preparing radial variable-density coral sand composite samples and performing consolidated drained triaxial tests under different area replacement rates, core-shell density ratios, and confining pressures. The results of the study show that the contribution of the core gradually increases with the increasing area replacement rate. The peak strength and peak friction angle of samples also increase gradually, but the growth tendency gradually slows down. The stress concentration coefficient of sample core is variable and follows a development pattern of first increasing and then decreasing. The secant Young's modulus of composite samples increases in a power function type with the increase of area replacement rate. The particle breakage of samples is mainly the rupture and abrasion of the 0.5–1 mm and 0.1–0.25 mm particle groups that serve as fillers. The research results can provide technical support for coral reef engineering construction.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"153 ","pages":"Article 104321"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659168","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

Response of bioinspired scale arrangement in a suction caisson to penetrating into clay reflected by using interface direct shear tests 通过界面直接剪切试验了解吸力沉箱中的生物启发鳞片排列对穿透粘土的反应

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2024-11-13 DOI: 10.1016/j.apor.2024.104322

Dayong Li, Yongan Ma, Jipeng Zhao

The suction caisson has been used to support the offshore wind turbine in last decade. Normally, the resistance of the traditional suction caisson (TSC) to penetrating into the seabed is overcome by suction resulting in high soil plug causing early termination in installation. Therefore, this study proposes a novel scaled suction caisson (SSC) that adopts the bionic design concept of little forward resistance and large backward resistance in scaled belly of reptiles like snakes. The bioinspired scale is set on the outer sidewall of the TSC, which is called the SSC. Scale arrangement is the key factor to reduce penetration resistance of the SSC. To simulate the penetration, the interfacial direct shear tests are carried out along the cranial direction (i.e., forward direction of the snake). The interfacial behavior of the scaled steel plate and clay is studied under different consolidation pressures and normal stresses. The results show that normal stress is the key factor compared with the consolidation pressure. There are clay-scale shear zone and clay-clay shear zone during shearing with the increase of the scale height, respectively. In addition, the theoretical formula for calculating critical shear stress is proposed, and the calculated results are in great agreement with the model test. As the scale height increases from 0.5 mm to 1.5 mm, the peak shear stress first increases and then decreases. Meanwhile, it is determined that the design of the scale height in the clay cannot exceed 108 d₅₀. Finally, the optimal geometric characteristics and scale arrangements of the SSC are determined by analyzing the peak shear stress and peak internal friction angle of various scale-clay interfaces. The results can contribute to optimizing the scales arrangement for easy penetration of the SSC in clay.

近十年来，吸力沉箱已被用于支撑海上风力涡轮机。通常情况下，传统吸力沉箱（TSC）深入海底的阻力会被吸力克服，造成高土塞，导致安装提前终止。因此，本研究提出了一种新型缩放式吸力沉箱（SSC），它采用了蛇等爬行动物缩放腹部的仿生设计理念，即前进阻力小，后退阻力大。生物启发的鳞片设置在 TSC 的外侧壁上，这就是 SSC。鳞片布置是降低 SSC 穿透阻力的关键因素。为模拟穿透，沿头颅方向（即蛇的前进方向）进行了界面直接剪切试验。在不同的固结压力和法向应力下，研究了鳞片钢板和粘土的界面行为。结果表明，与固结压力相比，法向应力是关键因素。随着鳞片高度的增加，剪切过程中分别存在粘土鳞片剪切区和粘土-粘土剪切区。此外，还提出了临界剪应力的理论计算公式，计算结果与模型试验结果非常吻合。随着鳞片高度从 0.5 mm 增加到 1.5 mm，峰值剪应力先增大后减小。同时，确定粘土中的鳞片高度设计不能超过 108 d50。最后，通过分析各种鳞片-粘土界面的峰值剪应力和峰值内摩擦角，确定了 SSC 的最佳几何特征和鳞片排列。这些结果有助于优化鳞片排列，使 SSC 易于穿透粘土。

{"title":"Response of bioinspired scale arrangement in a suction caisson to penetrating into clay reflected by using interface direct shear tests","authors":"Dayong Li, Yongan Ma, Jipeng Zhao","doi":"10.1016/j.apor.2024.104322","DOIUrl":"10.1016/j.apor.2024.104322","url":null,"abstract":"<div><div>The suction caisson has been used to support the offshore wind turbine in last decade. Normally, the resistance of the traditional suction caisson (TSC) to penetrating into the seabed is overcome by suction resulting in high soil plug causing early termination in installation. Therefore, this study proposes a novel scaled suction caisson (SSC) that adopts the bionic design concept of little forward resistance and large backward resistance in scaled belly of reptiles like snakes. The bioinspired scale is set on the outer sidewall of the TSC, which is called the SSC. Scale arrangement is the key factor to reduce penetration resistance of the SSC. To simulate the penetration, the interfacial direct shear tests are carried out along the cranial direction (i.e., forward direction of the snake). The interfacial behavior of the scaled steel plate and clay is studied under different consolidation pressures and normal stresses. The results show that normal stress is the key factor compared with the consolidation pressure. There are clay-scale shear zone and clay-clay shear zone during shearing with the increase of the scale height, respectively. In addition, the theoretical formula for calculating critical shear stress is proposed, and the calculated results are in great agreement with the model test. As the scale height increases from 0.5 mm to 1.5 mm, the peak shear stress first increases and then decreases. Meanwhile, it is determined that the design of the scale height in the clay cannot exceed 108 <em>d</em><sub>50</sub>. Finally, the optimal geometric characteristics and scale arrangements of the SSC are determined by analyzing the peak shear stress and peak internal friction angle of various scale-clay interfaces. The results can contribute to optimizing the scales arrangement for easy penetration of the SSC in clay.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104322"},"PeriodicalIF":4.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656214","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