Applied Ocean Research最新文献

{"title":"Pore-scale investigation of bubble evolution in shallow coastal gassy silt with micro-computed tomography","authors":"Zhenqi Guo ,&nbsp;Yunuo Liu ,&nbsp;Feiyan Jin ,&nbsp;Tao Liu ,&nbsp;Yan Zhang","doi":"10.1016/j.apor.2025.104609","DOIUrl":"10.1016/j.apor.2025.104609","url":null,"abstract":"<div><div>Shallow coastal gassy silts, characterized by isolated bubble trapping and heterogeneous bubble distribution within the sediment matrix, often serve as foundational substrates in nearshore and subsea engineering projects. Understanding the dynamic behavior of bubbles at the pore scale is crucial for evaluating the mechanical strength of gassy silts and their influence on engineering stability at a regional scale. In this study, we employed in-situ micro-computed tomography to investigate the effects of varying initial gas content and applied loading conditions on bubble evolution within gassy silts. Specimens were prepared using zeolite powder to simulate natural gas nucleation processes, with gas content levels of 2.0 % and 3.0 %, representing typical ranges of gas saturation observed in field conditions. These specimens were subjected to incrementally increasing vertical loads from 0 to 60 kPa, corresponding to pore scale stress conditions that simulate changes due to increasing water depths or geotechnical loads in coastal engineering applications. Our findings indicate that, with increasing stress, bubbles generally decrease in size, become more numerous, and shift toward more spherical shapes, aligning preferentially along directions parallel to stress transmission paths. The initial gas content plays a critical role in determining the processes of bubble evolution. Additionally, as loading intensifies, the total surface area of the bubbles decreases, suggesting a progression toward a more stable state for the gassy silt system overall. This work provides new pore-scale insights into bubble evolution in shallow coastal gassy silt.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"159 ","pages":"Article 104609"},"PeriodicalIF":4.3,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144070779","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}

{"title":"An experimental benchmark study on shape effects of structures under forced vertical oscillation: Flow fields, wave radiation, and hydrodynamic coefficients","authors":"Jannik Meyer ,&nbsp;Christian Windt ,&nbsp;Constantin Schweiger ,&nbsp;Clemens Krautwald ,&nbsp;Mario Welzel ,&nbsp;Arndt Hildebrandt ,&nbsp;Torsten Schlurmann ,&nbsp;Nils Goseberg","doi":"10.1016/j.apor.2025.104585","DOIUrl":"10.1016/j.apor.2025.104585","url":null,"abstract":"<div><div>Floating structures play a crucial role in transitioning from fossil fuels to renewable energies, either in floating offshore wind, floating solar, or wave energy applications. However, an accurate and efficient determination of the floating structures’ motion in waves remains a challenging task, particularly in mid-fidelity applications or applications with the aim of real-time capabilities: In particular, evaluating viscous effects and their importance for hydrodynamic damping is crucial. The wave radiation damping is often deemed dominant for vertically oscillating structures, but viscous effects cannot be neglected. The underlying physical processes of such viscous effects are not fully understood due to a lack of high-quality three-dimensional experimental flow field data. The present study investigates structures under forced vertical oscillation and aims at enhancing the physical understanding of the relation between structural shapes and features, the hydrodynamic parameters and the flow field using 3D time-resolved flow field measurements from a <em>particle tracking velocimetry</em> system. These investigations lead to a benchmark dataset for the development and validation of sophisticated numerical models which is published alongside this study. Three different generic box-type shapes are investigated: (i) a sharp-edged box, (ii) a round-edged box, and (iii) a box with a heave plate at the bottom. The experimental results show strong shape effects on the hydrodynamic coefficients, wave radiation, and the flow field. The radiated wave height can differ up to 50% between the three structures. Viscous effects from vortex structures and separation lead to a <span><math><mrow><mi>K</mi><mi>C</mi></mrow></math></span>-related increase of damping values for structures with sharp edges or heave plates. Significant shape effects on the vorticity are reported with a factor of up to 500% between the structures. Additionally to structural shape and features, the vorticity depends on <span><math><mrow><mi>K</mi><mi>C</mi></mrow></math></span> and oscillation frequency, while the vortex size solely depends on <span><math><mrow><mi>K</mi><mi>C</mi></mrow></math></span> and much less on structural shape (with a factor of up to 70%) and frequency. A comparison with potential flow simulations yields qualitatively good agreement to predict shape effects in added mass and radiation damping; however, a comparison between radiated wave heights from experiments and potential flow simulations indicates the necessity to validate potential flow results for quantitatively correct results.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"159 ","pages":"Article 104585"},"PeriodicalIF":4.3,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069679","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}

{"title":"P-y curve models for laterally loaded lattice-shaped diaphragm wall as sea-crossing bridge foundations","authors":"Jiujiang Wu ,&nbsp;Longjun Pu","doi":"10.1016/j.apor.2025.104610","DOIUrl":"10.1016/j.apor.2025.104610","url":null,"abstract":"<div><div>Lattice-shaped diaphragm walls (LSDWs) are novel foundation systems increasingly used in large-span, deep-water bridges for their exceptional rigidity, cost-efficiency, and adaptability to diverse geotechnical and marine environments. Despite their growing adoption, the lateral load-bearing behavior of LSDWs remains insufficiently studied. The <em>p-y</em> curve method is a widely used approach for analyzing the lateral behavior of deep foundations, relating lateral soil resistance to horizontal displacement. However, conventional <em>p-y</em> curve models, developed primarily for pile foundations, are not directly applicable to LSDWs due to differences in structural configuration and load transfer mechanisms. To address this gap, this study develops improved <em>p-y</em> curve models for single-chamber LSDWs, derived from comprehensive numerical simulations under horizontal static loads in cohesive and sandy soils. The models incorporate foundation dimension and depth effects, accurately predicting ultimate soil resistance and initial subgrade reaction modulus. Validation against published field tests and experimental data confirms their high accuracy in capturing lateral soil-structure interactions. These findings provide valuable guidance for optimizing the design and analysis of LSDW foundations in marine bridge construction.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"159 ","pages":"Article 104610"},"PeriodicalIF":4.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069672","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}

{"title":"Experimental investigations of local scour around piles in a single-column and three-columns with multiple rows in steady current","authors":"Ming Gong ,&nbsp;Guoxiang Wu ,&nbsp;Shengtao Du ,&nbsp;Xinying Pan ,&nbsp;Yingxue Lv ,&nbsp;Yunjia Sun ,&nbsp;Guangjia Ding ,&nbsp;Bingchen Liang","doi":"10.1016/j.apor.2025.104608","DOIUrl":"10.1016/j.apor.2025.104608","url":null,"abstract":"<div><div>Local scour around pile groups is a common phenomenon in fluvial and coastal engineering, leading to a reduction in the bearing capacity of pile foundations frequently. In this study, experimental tests were conducted in a flume to investigate local scour around piles arranged in tandems of single-column and three-columns, with rows ranging from 1 to 5. The objective was to examine the effects of upstream piles and lateral piles on local scour around downstream and central piles, respectively. Bed elevation profiles and temporal scour depths were measured and observed, respectively. The results revealed that sediment particles accumulated in the spaces between the third and the fifth rows in the 5 × 1 configuration, while local scour holes extended into these areas in the 5 × 3 configuration. Temporal scour depths were successfully fitted to an equation that divides the local scour process into three stages: initial, developing, and equilibrium scouring. Piles on either side of the central piles contributed to larger and deeper scour holes compared to those observed in a single-column arrangement. Furthermore, the equilibrium scour depth was found to decrease linearly with an increasing number of pile rows. Coefficients for both single-column and three-column configurations were proposed to estimate reductions in equilibrium scour depths, based on well-fitted curves derived from the experimental data.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"159 ","pages":"Article 104608"},"PeriodicalIF":4.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069676","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}

{"title":"Experimental investigation of passive cavitation control on a cylinder using proper orthogonal decomposition","authors":"Pankaj Kumar ,&nbsp;Ebrahim Kadivar ,&nbsp;Ould el Moctar","doi":"10.1016/j.apor.2025.104569","DOIUrl":"10.1016/j.apor.2025.104569","url":null,"abstract":"<div><div>Cavitation is known for its hazardous effects such as material erosion, noise, vibration and drop in efficiency of hydro turbomachines. There are various approaches to control cavitation: surface roughness, cavity generator (CG), obstacles, and ventilation with air/water jetting. In the present work, we are aiming to examine the cavitation suppression by using riblets on the surface of a circular cylinder. The experiment will be carried out for two kinds of scalloped riblets, horizontal (SC-H) and vertical (SC-V), and compared without riblet cylinder (plain) at Reynolds number 1 × 10⁵. The local force is measured by using a load cell and dynamic pressure is monitored through a pressure sensor. The cavitation structures are first captured through the high-speed camera and analyzed through image processing by using Matlab. It is found that the lift force amplitude varies from 1.2 N of the plain cylinder to 0.57 and 0.48 N for the cylinder with horizontal and vertical riblets respectively. The dynamics of the cavity behind the cylinder are visible in the time-averaged mean image. The image is separated into three regions for a more in-depth examination: the far field, the center field, and the area adjacent to the cylinder. This serves to highlight certain important facts about cavity dynamics. In order to emphasize the spatial and temporal dynamics of coherent structures, the proper orthogonal decomposition (POD) is used. It is discovered that the POD modes of coherent structures can be well explained by the first five modes. Furthermore, it is found that while SC-V is capable of stabilizing the cavitation structures by limiting fragmentation, SC-H substantially controls the cavitation and chaotic behavior.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104569"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886464","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}

{"title":"Research on sloshing characteristics for liquefied iron ore and size optimization of anti-sloshing baffle based on data-driven models","authors":"Jianyang Wu ,&nbsp;Jianwei Zhang ,&nbsp;Yijia Yu ,&nbsp;Zhenglv Shentu ,&nbsp;Mi-an Xue","doi":"10.1016/j.apor.2025.104604","DOIUrl":"10.1016/j.apor.2025.104604","url":null,"abstract":"<div><div>The impact of liquefied cargo sloshing on the safety of ship navigation has increased significantly in recent years. Implementing anti-sloshing baffles is an effective measure to mitigate the risk. However, the sloshing characteristics of liquefied iron ore should be addressed firstly. This paper employs a model experiment methodology using Carbomer 940 solution to simulate liquefied iron ore, given its similar rheological properties. The study examines the effects of filling level, excitation frequency and amplitude on the sloshing behavior. The sloshing characteristics were summarized. To determine the optimal size of the anti-sloshing baffle, a data-driven approach is utilized. Featuring motion period, baffle length, and baffle width as input variables, with impact pressure and center of gravity displacement as output variables, different prediction modes were established. The BPNN model demonstrates excellent generalization performance and identifies an optimal baffle size of 201.6 mm in length and 480 mm in width. This configuration reduces cargo gravity center displacement by 23.3 % compared to scenarios without baffles. This research not only fills a critical gap in the design of anti-sloshing devices for iron ore cargo ships but also provides a robust methodology for optimizing baffle sizes using advanced data-driven techniques.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104604"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927432","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}

{"title":"Machine learning-based prediction of hydrodynamic forces on small-diameter submarine pipelines: The influence of seabed roughness","authors":"M.S. Al-Khaldi,&nbsp;A. Al-Senafi,&nbsp;A. Taqi,&nbsp;F. Al-Amer,&nbsp;A. Al-Ragum,&nbsp;S. Neelamani","doi":"10.1016/j.apor.2025.104570","DOIUrl":"10.1016/j.apor.2025.104570","url":null,"abstract":"<div><div>Submarine pipelines are vital components of offshore energy infrastructure, used for transporting oil, gas, and renewable energy resources from sub-sea production sites to processing facilities. The main aim of this study is: first, to investigate the effect of varying seabed roughness and submarine pipeline diameter on the inline and lift wave forces acting on small-diameter pipelines; and second, to propose a quantitative method to determine the wave forces on small-diameter pipelines. Understanding and accurately predicting these hydrodynamic forces is crucial for ensuring the stability and integrity of small-diameter pipelines. To solve this problem, physical model investigations were carried out in a wave flume to assess inline and lift forces on slender pipelines of varying diameters, resting on seabeds with different roughness. The experimental data were used to compute inline and lift force coefficients, which were then utilized to train machine learning models for predictive analysis. It was found that seabed roughness and pipeline diameter significantly influence wave-induced forces. Machine learning (XGBoost) outperforms statistical methods in predictive accuracy but statistical models offer better interpretability for understanding force dynamics. Selecting the optimum quantitative method to determine the wave forces will help in the cost-effective and safe design of small submarine pipelines.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104570"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891120","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}

{"title":"Modelling of ship overtaking risk in restricted waters considering ship-ship interaction","authors":"Bing Wu ,&nbsp;Ou Liu ,&nbsp;Tsz Leung Yip ,&nbsp;C. Guedes Soares","doi":"10.1016/j.apor.2025.104573","DOIUrl":"10.1016/j.apor.2025.104573","url":null,"abstract":"<div><div>Overtaking in restricted waterways is a common navigation scenario with a high risk of collision due to ship-ship interaction and unexpected events. This paper proposes an analytical method for assessing overtaking risk in busy waterways by considering both longitudinal and transverse safe distances. The approach involves establishing a three-layer overtaking risk framework that identifies the influencing factors through scenario analysis of ship overtaking, ship-ship interaction, and ship-following. The safe criteria for fuzzification in both longitudinal and transverse directions are defined, and the overtaking risk is integrated using fuzzy logic. The proposed approach is applied to 100 historical data in the Yangtze River, and the results of high and very high overtaking scenarios show that the model provides a practical and reasonable assessment of ship overtaking risk. The proposed model can be used as decision support for ship navigation in busy waterways.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104573"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894876","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}

{"title":"Monte-Carlo simulation method for ship collision avoidance performance considering various encounter situations in port congestion zones","authors":"Dong-Hee Choi ,&nbsp;Hu-Jae Choi ,&nbsp;Kwang-Sung Ko ,&nbsp;Bo Woo Nam","doi":"10.1016/j.apor.2025.104589","DOIUrl":"10.1016/j.apor.2025.104589","url":null,"abstract":"<div><div>As interest in autonomous maritime technology continues to grow, various collision avoidance algorithms for autonomous vessels have been developed. However, evaluating and comparing the performance of these algorithms presents challenges due to the significant influence of factors such as the number of obstacles, specific encounter scenarios and obstacle arrangements. To address these challenges, the present study employs a Monte Carlo simulation technique to quantitatively evaluate the performance of ship collision avoidance algorithms in port congestion zones. To accurately reflect the conditions of real congested harbor areas with high ship traffic, four major encounter scenarios were defined, with the positions, velocities, and heading angles of obstacles randomly generated within predefined ranges to incorporate randomness into the simulation environment. Using the developed Monte Carlo simulation technique, the performance of the Worst Case Velocity Obstacle (WVO) algorithm and a hybrid algorithm combining WVO with modified Artificial Potential Field algorithm(APF) were qualitatively evaluated. The simulation results revealed the limitations of the WVO algorithm, particularly in scenarios involving crossing and converging encounters, due to frequent heading changes and passive rudder actions. In contrast, the hybrid algorithm, which incorporate WVO algorithm with modified APF method, demonstrated improved collision avoidance performances, including maintaining greater safe distance and reducing collision occurrence through actively using rudder angles.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104589"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921816","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}

{"title":"Long-term prediction of nonlinear ship roll motion using RAO","authors":"Sadaoki Matsui,&nbsp;Masayoshi Oka","doi":"10.1016/j.apor.2025.104590","DOIUrl":"10.1016/j.apor.2025.104590","url":null,"abstract":"<div><div>This study proposes two practical methods for estimating the long-term probability of the exceedance distribution of ship roll motion with nonlinear damping. One is based on our previously proposed RTP method, which is applicable to nonlinear roll motion but requires iterative computation of the response amplitude operator (RAO) of roll motion. In this work, we add a technique that eliminates iterative calculations without any loss of accuracy, thereby improving the practicality of the RTP method. The second is a simplified method called the wave height-iteration method, which can be performed using general linear long-term prediction tools without any dedicated programs. Both methods consist of a simple procedure based on the RAO of the roll motion considering nonlinear damping, which can easily be computed by linear seakeeping codes, and are extremely easy to implement. The results of numerical validation demonstrate that both are effective and practical methods for estimating the long-term distribution of the nonlinear roll motion. Furthermore, they can be applied not only to ship roll motion but also to other nonlinear responses, as long as the nonlinearity in irregular waves can be approximated by the nonlinearity in regular waves.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104590"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921842","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}