Pub Date : 2025-12-01Epub Date: 2025-05-06DOI: 10.1016/j.joes.2025.05.001
Liming Zhang , Deqing Yang , Qing Li , Jianghai Qiu
Applying distinctive designs to mechanical metamaterials is an effective way to achieve bandgap generation, widening and movement. In this paper, the bandgaps of metamaterials are tailored through the unique design of bending, folding, and twisting units and applied to the vibration-damping design of a marine water pump base. It is found that the bending operation generates a new complete bandgap and significantly enlarges the directional bandgap in the low-frequency region; the folding operation expands the directional bandgap in the high-frequency region; and the twisting operation generates and broadens the directional bandgap in the mid-frequency region. The application of the negative Poisson's ratio star-shaped metamaterial (NPRSM) cell, with a 60° bending angle, to vibration damping in a metamaterial ship pump base is presented. The new base achieved vibration attenuation of 43.435 dB and 60.282 dB over the bandgap ranges of 517.95 Hz - 668.36 Hz and 916.98 Hz - 965.03 Hz, respectively. In addition, the weight of the new base was reduced by 36.19 % compared to the conventional pump base, which is merely capable of bearing loads. This study provides an innovative design method for broadband vibration isolation and demonstrates the promising future of mechanical metamaterials in practical engineering applications.
{"title":"Tailor metamaterial bandgaps with bending, folding and twisting for the non-vibration ship pump base","authors":"Liming Zhang , Deqing Yang , Qing Li , Jianghai Qiu","doi":"10.1016/j.joes.2025.05.001","DOIUrl":"10.1016/j.joes.2025.05.001","url":null,"abstract":"<div><div>Applying distinctive designs to mechanical metamaterials is an effective way to achieve bandgap generation, widening and movement. In this paper, the bandgaps of metamaterials are tailored through the unique design of bending, folding, and twisting units and applied to the vibration-damping design of a marine water pump base. It is found that the bending operation generates a new complete bandgap and significantly enlarges the directional bandgap in the low-frequency region; the folding operation expands the directional bandgap in the high-frequency region; and the twisting operation generates and broadens the directional bandgap in the mid-frequency region. The application of the negative Poisson's ratio star-shaped metamaterial (NPRSM) cell, with a 60° bending angle, to vibration damping in a metamaterial ship pump base is presented. The new base achieved vibration attenuation of 43.435 dB and 60.282 dB over the bandgap ranges of 517.95 Hz - 668.36 Hz and 916.98 Hz - 965.03 Hz, respectively. In addition, the weight of the new base was reduced by 36.19 % compared to the conventional pump base, which is merely capable of bearing loads. This study provides an innovative design method for broadband vibration isolation and demonstrates the promising future of mechanical metamaterials in practical engineering applications.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 6","pages":"Pages 929-944"},"PeriodicalIF":11.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145469118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-01DOI: 10.1016/j.joes.2025.08.011
Lian-chao Wang , Baihua Yuan , Lu-Wen Zhang
Marine biofouling, i.e., the attachment of biomaterial on the surfaces of submerged objects, has long been a serious hazard to marine economies and ecosystems. Environmentally friendly degradable antifouling coatings developed in the last decade or so can efficiently replace traditional toxic antifouling coatings based on the following advantages: full degradability, non-discriminatory resistance to fouling, low addition of antifouling agents, and high compatibility with other antifouling mechanisms. However, current research and few available reviews neglect the degradation reaction kinetics mechanisms, resulting in the development of degradable coatings remaining in an inefficient trial-and-error stage. Here, we take a different approach, starting from degradation kinetics theoretical models and combining advances in microscopic simulation and computational research to reveal the degradation and antifouling mechanisms of highly efficient degradable polymers. From the novel perspective of layer-by-layer molecular structure design, we comprehensively analyze the optimization pathways for ester units, molecular chains, and network structures during the evolution of degradable polymers from main-chain degradation types to hyperbranched degradation types. We also summarize the achievements and future challenges of multi-functional composite coatings that synergize with multiple antifouling mechanisms to address the demands of complex marine environments. This review provides the theoretical basis and optimization criteria for the future development of degradable antifouling coatings and indicates that advanced computational models and theories are likely to further accelerate the design of antifouling polymers.
{"title":"Research progress of environmentally friendly degradable marine antifouling coatings","authors":"Lian-chao Wang , Baihua Yuan , Lu-Wen Zhang","doi":"10.1016/j.joes.2025.08.011","DOIUrl":"10.1016/j.joes.2025.08.011","url":null,"abstract":"<div><div>Marine biofouling, i.e., the attachment of biomaterial on the surfaces of submerged objects, has long been a serious hazard to marine economies and ecosystems. Environmentally friendly degradable antifouling coatings developed in the last decade or so can efficiently replace traditional toxic antifouling coatings based on the following advantages: full degradability, non-discriminatory resistance to fouling, low addition of antifouling agents, and high compatibility with other antifouling mechanisms. However, current research and few available reviews neglect the degradation reaction kinetics mechanisms, resulting in the development of degradable coatings remaining in an inefficient trial-and-error stage. Here, we take a different approach, starting from degradation kinetics theoretical models and combining advances in microscopic simulation and computational research to reveal the degradation and antifouling mechanisms of highly efficient degradable polymers. From the novel perspective of layer-by-layer molecular structure design, we comprehensively analyze the optimization pathways for ester units, molecular chains, and network structures during the evolution of degradable polymers from main-chain degradation types to hyperbranched degradation types. We also summarize the achievements and future challenges of multi-functional composite coatings that synergize with multiple antifouling mechanisms to address the demands of complex marine environments. This review provides the theoretical basis and optimization criteria for the future development of degradable antifouling coatings and indicates that advanced computational models and theories are likely to further accelerate the design of antifouling polymers.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 6","pages":"Pages 1192-1218"},"PeriodicalIF":11.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145469101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-01-13DOI: 10.1016/j.joes.2025.01.002
Peng Jiang, Yichen Huang, Yong Cao, Shijun Liao, Bin Xie
The objective of this work is to investigate the utility and effectiveness of the high-order scheme for simulating unsteady turbulent flows. To achieve it, the studies are conducted from two perspectives: (i) the ability of different numerical schemes to accurately simulate turbulence problems using the same set of meshes; and (ii) the accuracy and stability of higher-order schemes for solving turbulence statistics for different mesh types (hexahedral, tetrahedral, and polyhedral cells). The simulations employ the third-order scheme for spatial discretization of the governing equations, while a widely-used second-order solver, namely pisoFoam, is employed for comparison. This study considers the canonical cases of the two-dimensional Taylor-Green vortex (2D TGV) problem at and flow past a sphere at to address the aforementioned two key issues. For the TGV case, the high-order model significantly improves the numerical accuracy with convergence rates and reduces the numerical dissipation of nearly 1/10 of pisoFoam on different meshing types. In the latter case, the high-order scheme with large-eddy simulation (LES) accurately predicts the vortex structures and the flow instability, regardless of grid type. However, pisoFoam is found to be sensitive to mesh types, which results in numerous non-physical structures in the flow field due to numerical noise rather than flow physics, particularly for tetrahedral cells. Furthermore, for the typical low- and high-order flow statistics, the numerical results predicted by the present model show better agreement with the reference data and have less dependence on the type of grids compared with the conventional scheme. In addition, the obtained energy spectrum by the high-order solver accurately captures the Kelvin-Helmholtz (K-H) instability and the vortex shedding frequency, while these important features are less pronounced by the traditional low-order model.
{"title":"Utility of high-order scheme for unsteady flow simulations: Comparison with second-order tool","authors":"Peng Jiang, Yichen Huang, Yong Cao, Shijun Liao, Bin Xie","doi":"10.1016/j.joes.2025.01.002","DOIUrl":"10.1016/j.joes.2025.01.002","url":null,"abstract":"<div><div>The objective of this work is to investigate the utility and effectiveness of the high-order scheme for simulating unsteady turbulent flows. To achieve it, the studies are conducted from two perspectives: (i) the ability of different numerical schemes to accurately simulate turbulence problems using the same set of meshes; and (ii) the accuracy and stability of higher-order schemes for solving turbulence statistics for different mesh types (hexahedral, tetrahedral, and polyhedral cells). The simulations employ the third-order scheme for spatial discretization of the governing equations, while a widely-used second-order solver, namely pisoFoam, is employed for comparison. This study considers the canonical cases of the two-dimensional Taylor-Green vortex (2D TGV) problem at <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>100</mn><mo>,</mo><mspace></mspace><mn>1600</mn></mrow></math></span> and flow past a sphere at <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>10</mn><mspace></mspace><mn>000</mn></mrow></math></span> to address the aforementioned two key issues. For the TGV case, the high-order model significantly improves the numerical accuracy with convergence rates and reduces the numerical dissipation of nearly 1/10 of pisoFoam on different meshing types. In the latter case, the high-order scheme with large-eddy simulation (LES) accurately predicts the vortex structures and the flow instability, regardless of grid type. However, pisoFoam is found to be sensitive to mesh types, which results in numerous non-physical structures in the flow field due to numerical noise rather than flow physics, particularly for tetrahedral cells. Furthermore, for the typical low- and high-order flow statistics, the numerical results predicted by the present model show better agreement with the reference data and have less dependence on the type of grids compared with the conventional scheme. In addition, the obtained energy spectrum by the high-order solver accurately captures the Kelvin-Helmholtz (K-H) instability and the vortex shedding frequency, while these important features are less pronounced by the traditional low-order model.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 774-787"},"PeriodicalIF":11.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2024-09-17DOI: 10.1016/j.joes.2024.08.002
Jiankun Lou , Hongdong Wang , Wenliang Yuan , Hong Yi
The accuracy of ship manoeuvrability models based on real sea trail data heavily relies on data quality, as noise and measurement errors pose significant challenges in data processing and model training. This study employs a deep learning approach for the nonparametric modelling of 3-DoF ship manoeuvrability predictions, utilizing data from zigzag tests conducted at sea. It examines how the limitations of measurement equipment affect data analysis, emphasizing the impact of different sample intervals on model accuracy. Our study further explores the efficacy of deep neural networks in capturing low-frequency components more effectively than high-frequency ones, discussing the data sampling process and frequency analysis in the response domain for training set construction. Simulation results indicate that both excessively small and large sample intervals can significantly compromise predictions of motion, location, and heading angles. Moreover, to enhance the evaluation of the deep learning-based nonparametric model, incorporating a test case with a minimal rudder angle is crucial for assessing the prediction precision. Generally, a sample interval ranging from 0.4 s to 0.6 s is identified as optimal for data down sampling in real sea trails, balancing accuracy and computational efficiency.
{"title":"Influence of sample intervals in real-sea trails on the nonparametric model of 3-DoF ship motion predictions","authors":"Jiankun Lou , Hongdong Wang , Wenliang Yuan , Hong Yi","doi":"10.1016/j.joes.2024.08.002","DOIUrl":"10.1016/j.joes.2024.08.002","url":null,"abstract":"<div><div>The accuracy of ship manoeuvrability models based on real sea trail data heavily relies on data quality, as noise and measurement errors pose significant challenges in data processing and model training. This study employs a deep learning approach for the nonparametric modelling of 3-DoF ship manoeuvrability predictions, utilizing data from zigzag tests conducted at sea. It examines how the limitations of measurement equipment affect data analysis, emphasizing the impact of different sample intervals on model accuracy. Our study further explores the efficacy of deep neural networks in capturing low-frequency components more effectively than high-frequency ones, discussing the data sampling process and frequency analysis in the response domain for training set construction. Simulation results indicate that both excessively small and large sample intervals can significantly compromise predictions of motion, location, and heading angles. Moreover, to enhance the evaluation of the deep learning-based nonparametric model, incorporating a test case with a minimal rudder angle is crucial for assessing the prediction precision. Generally, a sample interval ranging from 0.4 s to 0.6 s is identified as optimal for data down sampling in real sea trails, balancing accuracy and computational efficiency.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 621-645"},"PeriodicalIF":11.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2024-11-16DOI: 10.1016/j.joes.2024.11.001
Zhiyao Li , Yiming Zhu , Yiting Wang , Yong Zhang , Lei Wang
To solve the path following problem in navigation tasks for under-actuated autonomous surface vehicles (ASVs), this paper proposed a path following control method which combines trajectory dataset of random ship motion and offline reinforcement learning (RM-ORL). The method does not require the reinforcement learning (RL) agent to interact with the environment while training the policy, and it can obtain training datasets with a lower cost. In RM-ORL, the irregular motion data of the ASV in open water is first collected. Then the desired path is reconstructed using the B-spline function and the path points along the motion trajectories. Thus the offline dataset will be enhanced with the motion data and the new path. Finally, the conservative Q-learning algorithm is utilized to train the path following controller. The path deviation in simulation maps, rudder data and ship motion parameters of RM-ORL, online RL and other offline RL policies trained on different datasets are compared. The simulation results illustrate that the RM-ORL achieves comparable path following accuracy to that of online RL agent and offline RL agent trained on expert data, while surpassing the one trained on online agent replay buffer data. The rudder steering amplitude of RM-ORL is also smaller than that of other policies, which verifies the effectiveness of our method applied to the path following control of under-actuated ASV.
{"title":"Path following control of under-actuated autonomous surface vehicle based on random motion trajectory dataset and offline reinforcement learning","authors":"Zhiyao Li , Yiming Zhu , Yiting Wang , Yong Zhang , Lei Wang","doi":"10.1016/j.joes.2024.11.001","DOIUrl":"10.1016/j.joes.2024.11.001","url":null,"abstract":"<div><div>To solve the path following problem in navigation tasks for under-actuated autonomous surface vehicles (ASVs), this paper proposed a path following control method which combines trajectory dataset of random ship motion and offline reinforcement learning (RM-ORL). The method does not require the reinforcement learning (RL) agent to interact with the environment while training the policy, and it can obtain training datasets with a lower cost. In RM-ORL, the irregular motion data of the ASV in open water is first collected. Then the desired path is reconstructed using the B-spline function and the path points along the motion trajectories. Thus the offline dataset will be enhanced with the motion data and the new path. Finally, the conservative Q-learning algorithm is utilized to train the path following controller. The path deviation in simulation maps, rudder data and ship motion parameters of RM-ORL, online RL and other offline RL policies trained on different datasets are compared. The simulation results illustrate that the RM-ORL achieves comparable path following accuracy to that of online RL agent and offline RL agent trained on expert data, while surpassing the one trained on online agent replay buffer data. The rudder steering amplitude of RM-ORL is also smaller than that of other policies, which verifies the effectiveness of our method applied to the path following control of under-actuated ASV.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 724-744"},"PeriodicalIF":11.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The wave run-up along the column surface is one of the focal issues of research in ocean engineering. This experimental study aimed to reveal the wave run-up characteristics of a fixed four-square-column array with rounded corners under focused waves by controlling wave steepness, spectral peak period, wave direction, and focus position. The experiment utilized a 1:50 scale physical model, with focused waves generated in a wave tank to simulate extreme sea conditions. Four squared columns were fixed to the tank carriage. Eighteen wave probes were installed around the fore and rear columns to measure wave run-ups. The results indicated that with an increase in wave steepness, the wave run-up ratio demonstrates an increasing trend, particularly when the waves approach or precisely break at the focal point. Furthermore, the wave run-up ratio on the front column decreases as the spectral peak period increases, owing to the weakening of the nonlinear wave-column interaction when the wavelength is significantly larger than the column width. For the rear column, the dissipation of wave energy by the front column leads to a notably lower wave run-up ratio. However, under the influence of incident focused waves at certain wavelengths, the rear column may experience a more intense secondary run-up phenomenon. Additionally, comparative analysis of different focus positions revealed that the wave run-up ratio is maximized when the focus position is located behind the front column. The incident waves at 45° were diffracted by the rounded corners of the columns, leading to the dispersion of wave energy and consequently yielding a reduced wave run-up ratio. The experimental data obtained serve as crucial benchmarks for validating further numerical simulations of wave impact on rounded square columns.
{"title":"An experimental study on wave run-ups of fixed four-rounded-square-column array in focused waves","authors":"Meng Shan , Longfei Xiao , Wencheng Wu , Yufeng Kou , Kelu Li","doi":"10.1016/j.joes.2024.12.003","DOIUrl":"10.1016/j.joes.2024.12.003","url":null,"abstract":"<div><div>The wave run-up along the column surface is one of the focal issues of research in ocean engineering. This experimental study aimed to reveal the wave run-up characteristics of a fixed four-square-column array with rounded corners under focused waves by controlling wave steepness, spectral peak period, wave direction, and focus position. The experiment utilized a 1:50 scale physical model, with focused waves generated in a wave tank to simulate extreme sea conditions. Four squared columns were fixed to the tank carriage. Eighteen wave probes were installed around the fore and rear columns to measure wave run-ups. The results indicated that with an increase in wave steepness, the wave run-up ratio demonstrates an increasing trend, particularly when the waves approach or precisely break at the focal point. Furthermore, the wave run-up ratio on the front column decreases as the spectral peak period increases, owing to the weakening of the nonlinear wave-column interaction when the wavelength is significantly larger than the column width. For the rear column, the dissipation of wave energy by the front column leads to a notably lower wave run-up ratio. However, under the influence of incident focused waves at certain wavelengths, the rear column may experience a more intense secondary run-up phenomenon. Additionally, comparative analysis of different focus positions revealed that the wave run-up ratio is maximized when the focus position is located behind the front column. The incident waves at 45° were diffracted by the rounded corners of the columns, leading to the dispersion of wave energy and consequently yielding a reduced wave run-up ratio. The experimental data obtained serve as crucial benchmarks for validating further numerical simulations of wave impact on rounded square columns.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 800-818"},"PeriodicalIF":11.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-01-22DOI: 10.1016/j.joes.2024.12.004
Jianmei Chen , Zhe Chen , Qiang Ma , Yuqing Zhang , Yanping He
Polar Carriers operate in both open water and brash ice areas, where differing navigation environments impose varying requirements on hull form design. Determining the proportion of these navigation areas is crucial for achieving a balanced hull form that optimizes both open water performance and ice-going capabilities. This paper proposes a Navigation State Recognition Model (NSRM) that utilizes GPS data from ship tracks to distinguish between different navigation states, allowing for an assessment of the proportion of open water and brash ice encountered during voyages. Based on the NSRM, a rapid hull form optimization method is developed for polar ships, aiming to minimize total resistance across both open water and brash ice areas. The total resistance is calculated using a weighted sum of the resistances in ice-covered and open-water sections of the route, as determined by the NSRM. The Rankine source and Reynolds-Averaged Navier-Stokes (RANS) methods are employed to calculate open-water resistance, while Juva and Riskas formula is used to estimate ice resistance in brash ice conditions. Additionally, the optimization method is applied to a parent ship with an invisible bulbous bow, resulting in an optimized bow hull form. This demonstrates the applicability of the NSRM-based optimization method for the design of Polar Carrier hull forms.
极地航母可以在开阔水域和浮冰区域运行，不同的航行环境对船体形状设计提出了不同的要求。确定这些导航区域的比例对于实现平衡的船体形状至关重要，从而优化开放水域性能和冰上能力。本文提出了一种导航状态识别模型（NSRM），该模型利用来自船舶轨迹的GPS数据来区分不同的导航状态，从而可以评估航行中遇到的开阔水域和浮冰的比例。在此基础上，提出了一种用于极地船舶的船体形状快速优化方法，旨在使开放水域和浮冰区域的总阻力最小。总阻力是根据NSRM确定的路线冰雪覆盖部分和开放水域部分阻力的加权和来计算的。开放水域阻力计算采用Rankine源法和reynolds - average Navier-Stokes （RANS）法，浮冰条件下冰阻力计算采用Juva和Riskas公式。此外，将该优化方法应用于具有隐形球首的母船，得到了最优的船首船体形状。这证明了基于nsrm的优化方法在极地航母船型设计中的适用性。
{"title":"Hull form optimization for polar carrier based on navigation state recognition model","authors":"Jianmei Chen , Zhe Chen , Qiang Ma , Yuqing Zhang , Yanping He","doi":"10.1016/j.joes.2024.12.004","DOIUrl":"10.1016/j.joes.2024.12.004","url":null,"abstract":"<div><div>Polar Carriers operate in both open water and brash ice areas, where differing navigation environments impose varying requirements on hull form design. Determining the proportion of these navigation areas is crucial for achieving a balanced hull form that optimizes both open water performance and ice-going capabilities. This paper proposes a Navigation State Recognition Model (NSRM) that utilizes GPS data from ship tracks to distinguish between different navigation states, allowing for an assessment of the proportion of open water and brash ice encountered during voyages. Based on the NSRM, a rapid hull form optimization method is developed for polar ships, aiming to minimize total resistance across both open water and brash ice areas. The total resistance is calculated using a weighted sum of the resistances in ice-covered and open-water sections of the route, as determined by the NSRM. The Rankine source and Reynolds-Averaged Navier-Stokes (RANS) methods are employed to calculate open-water resistance, while Juva and Riskas formula is used to estimate ice resistance in brash ice conditions. Additionally, the optimization method is applied to a parent ship with an invisible bulbous bow, resulting in an optimized bow hull form. This demonstrates the applicability of the NSRM-based optimization method for the design of Polar Carrier hull forms.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 819-829"},"PeriodicalIF":11.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-01-13DOI: 10.1016/j.joes.2024.12.001
Susana Costa , Tiago C.A. Oliveira , Ali Abdolali
Wind-wave steepness along the North Atlantic (27.46 N < lat < 43.53 N and 62.03 W < lon < 80.19 W) is characterized based on at most 37 years (1984 to 2020) of buoy measurements. Wave data from 16 National Data Buoy Center (NDBC) and 2 Marine Environmental Data Section (MEDS) stations located at depths ranging from 33 m to 5394 m are used. Intra-annual variability of the full spectrum wave steepness (sm) and the wind-sea steepness (smw) are analyzed. Among the 18 locations, the average sm and smw ranged between 0.023 to 0.037 and 0.025 to 0.039, respectively. Results show similar intra-annual variability among the different buoys both for sm and for smw with monthly average maximums occurring between January and February (0.029 < sm < 0.045, 0.030 < smw < 0.048) and minimums between July and August (0.018<sm<0.033, 0.019 < smw < 0.035). The probability distribution function of sm/smw presents a peak between 0.9 and 1.0 for all stations. It is also found that the sea states with the maximum sm and smw are not directly linked to the maximum events of significant wave height. Practically, these findings can inform the implementation of various ocean engineering endeavors as well as navigation risk determination, as wave steepness exerts a significant influence on several physical processes in the marine environment.
{"title":"Wind-wave steepness offshore the North American east coast","authors":"Susana Costa , Tiago C.A. Oliveira , Ali Abdolali","doi":"10.1016/j.joes.2024.12.001","DOIUrl":"10.1016/j.joes.2024.12.001","url":null,"abstract":"<div><div>Wind-wave steepness along the North Atlantic (27.46 N < lat < 43.53 N and 62.03 W < lon < 80.19 W) is characterized based on at most 37 years (1984 to 2020) of buoy measurements. Wave data from 16 National Data Buoy Center (NDBC) and 2 Marine Environmental Data Section (MEDS) stations located at depths ranging from 33 m to 5394 m are used. Intra-annual variability of the full spectrum wave steepness (<em>s</em><sub>m</sub>) and the wind-sea steepness (<em>s</em><sub>mw</sub>) are analyzed. Among the 18 locations, the average <em>s</em><sub>m</sub> and <em>s</em><sub>mw</sub> ranged between 0.023 to 0.037 and 0.025 to 0.039, respectively. Results show similar intra-annual variability among the different buoys both for <em>s</em><sub>m</sub> and for <em>s</em><sub>mw</sub> with monthly average maximums occurring between January and February (0.029 < <em>s</em><sub>m</sub> < 0.045, 0.030 < <em>s</em><sub>mw</sub> < 0.048) and minimums between July and August (0.018<<em>s</em><sub>m</sub><0.033, 0.019 < <em>s</em><sub>mw</sub> < 0.035). The probability distribution function of <em>s</em><sub>m</sub>/<em>s</em><sub>mw</sub> presents a peak between 0.9 and 1.0 for all stations. It is also found that the sea states with the maximum <em>s</em><sub>m</sub> and <em>s</em><sub>mw</sub> are not directly linked to the maximum events of significant wave height. Practically, these findings can inform the implementation of various ocean engineering endeavors as well as navigation risk determination, as wave steepness exerts a significant influence on several physical processes in the marine environment.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 745-760"},"PeriodicalIF":11.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2025-04-15DOI: 10.1016/j.joes.2025.04.001
Qing-Hua Zhou , Hong-Xiang Xue , Ke-Yi Hu , Hong-Rui Liu , Wen-Ling Tu
Type B cargo tanks in Very Large Ethane Carriers (VLECs), constructed with 5 % Ni steel, exhibit non-negligible probability of cryogenic liquid leakage due to fatigue failure in welded joints under cyclic loads and the presence of pre-existing surface cracks. This study systematically investigates the fatigue and fracture behavior of 5 % Ni steel submerged arc welded (SAW) joints through tensile, fracture toughness, and fatigue crack propagation (FCP) tests at 23 °C and -110 °C. Results demonstrate the SAW joints exhibited superior cryogenic mechanical properties compared to those under ambient condition. A novel methodology integrating critical fatigue fracture location identification and FCP life analysis was developed, utilizing a Weibull-distributed random wave-induced load spectrum generated via Python to simulate operational stresses. FCP analysis using failure assessment diagram (FAD) and the Paris law model revealed critical crack sizes and remaining life at tank vertical support toes. Additionally, the influence of material properties and temperatures on FCP life was quantitatively evaluated. This study addresses the lack of fracture toughness and Paris parameters for 5 % Ni steel SAW joints, providing essential reference for damage tolerance design and safe operation of VLEC type B tanks under cryogenic conditions.
{"title":"Experimental and analytical investigation on cryogenic fatigue and fracture behavior of 5% Ni steel welded joints for LEG type B cargo tank","authors":"Qing-Hua Zhou , Hong-Xiang Xue , Ke-Yi Hu , Hong-Rui Liu , Wen-Ling Tu","doi":"10.1016/j.joes.2025.04.001","DOIUrl":"10.1016/j.joes.2025.04.001","url":null,"abstract":"<div><div>Type B cargo tanks in Very Large Ethane Carriers (VLECs), constructed with 5 % Ni steel, exhibit non-negligible probability of cryogenic liquid leakage due to fatigue failure in welded joints under cyclic loads and the presence of pre-existing surface cracks. This study systematically investigates the fatigue and fracture behavior of 5 % Ni steel submerged arc welded (SAW) joints through tensile, fracture toughness, and fatigue crack propagation (FCP) tests at 23 °C and -110 °C. Results demonstrate the SAW joints exhibited superior cryogenic mechanical properties compared to those under ambient condition. A novel methodology integrating critical fatigue fracture location identification and FCP life analysis was developed, utilizing a Weibull-distributed random wave-induced load spectrum generated via Python to simulate operational stresses. FCP analysis using failure assessment diagram (FAD) and the Paris law model revealed critical crack sizes and remaining life at tank vertical support toes. Additionally, the influence of material properties and temperatures on FCP life was quantitatively evaluated. This study addresses the lack of fracture toughness and Paris parameters for 5 % Ni steel SAW joints, providing essential reference for damage tolerance design and safe operation of VLEC type B tanks under cryogenic conditions.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 864-877"},"PeriodicalIF":11.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01Epub Date: 2024-09-21DOI: 10.1016/j.joes.2024.09.001
Ming Zou , Xiang-Jie Tang , Lu Zou , Zao-Jian Zou , Chang-Zhe Chen , Xin-Shu Zhang
Different from the existing CFD-DEM models in which the ship remains stationary, a CFD-DEM model with the ship in forward motion is proposed in this paper to simulate the process of a ship sailing across pack ice area at a forward speed under different drafts. A high-precision method for generating pack ice area on the undisturbed free surface that can be used in conjunction with the proposed model is introduced. Taking an ice-strengthened Panamax bulker as study object, the available model test results are used to verify the reliability of the proposed model, which shows that the model can effectively evaluate the resistance performance and simulate the ship-ice-water interaction. Based on the verified model, the ice resistances on different parts of the hull are first investigated, which reveals that the ice resistance of the bow is most significant, while those of the midship and stern are negligible. Then, the speed dependence of ice resistance under different drafts is studied. It shows a strong nonlinearity under shallow draft, while the nonlinearity gradually weakens as the draft increases. Finally, the proportions of ice resistance and open-water resistance in the total resistance under different drafts and ship speeds are discussed.
{"title":"Numerical simulations of a ship sailing across pack ice area in forward motion under different drafts","authors":"Ming Zou , Xiang-Jie Tang , Lu Zou , Zao-Jian Zou , Chang-Zhe Chen , Xin-Shu Zhang","doi":"10.1016/j.joes.2024.09.001","DOIUrl":"10.1016/j.joes.2024.09.001","url":null,"abstract":"<div><div>Different from the existing CFD-DEM models in which the ship remains stationary, a CFD-DEM model with the ship in forward motion is proposed in this paper to simulate the process of a ship sailing across pack ice area at a forward speed under different drafts. A high-precision method for generating pack ice area on the undisturbed free surface that can be used in conjunction with the proposed model is introduced. Taking an ice-strengthened Panamax bulker as study object, the available model test results are used to verify the reliability of the proposed model, which shows that the model can effectively evaluate the resistance performance and simulate the ship-ice-water interaction. Based on the verified model, the ice resistances on different parts of the hull are first investigated, which reveals that the ice resistance of the bow is most significant, while those of the midship and stern are negligible. Then, the speed dependence of ice resistance under different drafts is studied. It shows a strong nonlinearity under shallow draft, while the nonlinearity gradually weakens as the draft increases. Finally, the proportions of ice resistance and open-water resistance in the total resistance under different drafts and ship speeds are discussed.</div></div>","PeriodicalId":48514,"journal":{"name":"Journal of Ocean Engineering and Science","volume":"10 5","pages":"Pages 646-660"},"PeriodicalIF":11.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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