Applied Ocean Research最新文献

{"title":"Effect of flow deflectors on local scour around artificial reefs under steady current: Experimental and numerical investigations","authors":"Xianyi Liu,&nbsp;Xinxin Wang,&nbsp;Fenfang Zhao,&nbsp;Huaxiang Sheng","doi":"10.1016/j.apor.2025.104509","DOIUrl":"10.1016/j.apor.2025.104509","url":null,"abstract":"<div><div>Artificial reefs are submerged structures used to rehabilitate marine ecosystems and restore fishery resources. Field investigations have revealed that local scour poses a significant threat to these structures in various regions. Despite this, there is limited research on scour countermeasures for artificial reefs and a lack of understanding regarding the flow patterns that influence scour. This study examines the effects of different deflectors on scour depth and flow patterns around artificial reefs, focusing on a control model (AR1) and an optimized model (AR11). The experiments were conducted under steady, unidirectional current conditions. Flume experiments demonstrated that AR11 reduced the maximum scour depth by approximately 46 % compared to AR1 and effectively prevented reef tilting. Flow fields on the scour bed of AR1 and AR11 were reconstructed using hydrodynamic modelling of scour topography and computational fluid dynamics (CFD). The analysis revealed that the main flow features affecting the scour around AR1 were a counterclockwise vortex on its side and a vortex within the scour hole. In contrast, AR11 effectively mitigated the adverse effects of these vortices, thereby reducing scour around the artificial reef.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104509"},"PeriodicalIF":4.3,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610701","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}

{"title":"An extended two-layer viscous Boussinesq-type model for surface gravity waves: Including the effect of bottom friction","authors":"Hao Sun ,&nbsp;Yang Zhao ,&nbsp;Zhongbo Liu ,&nbsp;Yong Liu","doi":"10.1016/j.apor.2025.104495","DOIUrl":"10.1016/j.apor.2025.104495","url":null,"abstract":"<div><div>Wave propagation is accompanied by energy attenuation owing to the water viscosity. Based on the two-layer viscous Boussinesq-type model considering of deep-water waves, the bottom friction term is incorporated to further simulate wave energy dissipation for limited-depth and shallow water waves. The viscous effects at the free surface and the seabed are analyzed based on analytical linear dispersion. Linear dispersion relation of present model is obtained using Stokes-type Fourier analysis and compared with the analytical solution, where the linear phase celerity and damping rate of the model is accurate for <em>h</em>/<em>L</em>₀ ≤ 8.0 and 5.22 (<em>h</em> is water depth and <em>L</em>₀ is characteristic wavelength) within 1% error, respectively. The finite difference method is employed for numerical implementation, and the computed results are compared with analytical solutions and related experimental data. Remarkable agreements demonstrate the accuracy of the numerical procedure and verify the importance of bottom friction. This article discusses the dimensionless water depth corresponding to the maximum damping rate caused by bottom friction and comparing the different methods to consider bottom friction. The value of bottom friction coefficient is also explored based on experiments.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104495"},"PeriodicalIF":4.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593206","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}

{"title":"Global evaluation of wave data reanalysis: Comparison of the ERA5 dataset to buoy observations","authors":"Victoria Bessonova ,&nbsp;Evdokia Tapoglou ,&nbsp;Robert Dorrell ,&nbsp;Nina Dethlefs ,&nbsp;Katharine York","doi":"10.1016/j.apor.2025.104490","DOIUrl":"10.1016/j.apor.2025.104490","url":null,"abstract":"<div><div>Wave reanalysis data are critical to multiple industries including commerce, fisheries, petroleum, offshore wind, the design and the construction of maritime structures. One of the most used datasets is ERA5 developed by the European Centre for Medium Range Forecast. The accuracy and reliability of this dataset have not been rigorously assessed on a global scale. We present the first global evaluation of ERA5 significant wave height against measurements from 444 buoys worldwide. We demonstrate the influence of critical control factors including distance to shore, water depth, regional characteristics and seasonality. Results showed that ERA5 underestimates significant wave height in extreme conditions. This underestimation could lead to underestimating the severity of predicted wave conditions when designing vessels or foundations for maritime structures. ERA5 accuracy increases farther from shore, but does not change significantly with increasing water depth. In the Northern Hemisphere, the RMSE and absolute bias between ERA5 and measured significant wave height are up to 0.25 m lower in summer than in winter. Seasonal patterns are less pronounced in the Southern Hemisphere. The results provide global confidence levels for the robust use of ERA5 data, and establish a methodology to test future datasets.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104490"},"PeriodicalIF":4.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593205","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}

{"title":"Numerical study on internal waves generated by a submerged body moving in two types of stratified fluids","authors":"Xuebin Chen ,&nbsp;Shuqun Cai ,&nbsp;Jiexin Xu ,&nbsp;Shuyan Deng","doi":"10.1016/j.apor.2025.104513","DOIUrl":"10.1016/j.apor.2025.104513","url":null,"abstract":"<div><div>A numerical model is employed to simulate the internal waves generated by a moving submerged body in stratified fluids through the joint solution of the Navier-Stokes equations and the density transport equation. It is found the generation of internal waves begins with the formation of elevation and depression regions at the front and rear ends of the submerged body. As the body moves, more pairs of elevation and depression regions emerge in the wake, progressively leading to the full evolution of divergent and transverse wave features. Internal waves generated in two types of stratified fluids are compared, inferring the similarity of internal waves between two stratified fluids is not restricted to a specific depth but is consistently observed across all depths, and this similarity encompasses main flow characteristics, including internal wave surface fluctuation, pressure, and velocity components. However, an equivalent of Froude number, Fr, is only a necessary condition for the similarity, which does not guarantee the similarity between cases with different density stratifications. A water depth-based Froude number, Fr’(z), is proposed in this paper to investigate similarity. It has been shown that similarity is ensured when the Fr’(z) values of these cases are equal at any water depth.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104513"},"PeriodicalIF":4.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593203","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}

{"title":"Sea level forecasting using deep recurrent neural networks with high-resolution hydrodynamic model","authors":"Saeed Rajabi-Kiasari ,&nbsp;Artu Ellmann ,&nbsp;Nicole Delpeche-Ellmann","doi":"10.1016/j.apor.2025.104496","DOIUrl":"10.1016/j.apor.2025.104496","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Changes in climate, along with increasing marine activities in coastal and offshore regions, highlight the need for effective sea level forecasting methods. In recent years, forecasting techniques, especially those utilizing machine learning/deep learning methods (ML/DL), have shown promising capabilities. However, sea level forecasting is often limited in accuracy and spatiotemporal coverage, primarily due to the challenges posed by available observational data, which complicates the assessment of existing ML/DL techniques in complex and dynamic regions like the Baltic Sea. This study addresses these challenges by utilizing a high-resolution spatiotemporal framework that integrates high-resolution hydrodynamic and marine geoid models available to Baltic countries, enabling further capabilities to be explored in terms of sea level accuracy and validation. Specifically, it examines short-term sea level forecasting in the eastern Baltic Sea and the potential of utilizing two recurrent neural network-based models such as the Long Short-Term Memory Networks (LSTMs), and the Gated Recurrent Unit (GRU) along with high-resolution input data sources. These models were specifically chosen, due to their expected capabilities with time series data and their ability to learn both short and long-term connections of the input datasets.&lt;/div&gt;&lt;div&gt;To achieve this, a multivariate multistep-ahead (3, 6, 9, 12, and 24 h) forecasting framework was developed. The DL models' input components are high-resolution sea level data obtained from a bias-corrected hydrodynamic model, wind speed, surface pressure, and sea surface temperature. Results for various time steps (from 3 h to 24 h ahead), during the test period, revealed that the two DL models generally showed similar performance, with slightly superior results with the GRU model. For instance, GRU and LSTM showed an averaged root mean square error (RMSE) of 4.96 cm and 5.3 cm and a coefficient of determination (R²) of 0.93 and 0.92, respectively. Investigations of the time series forecasting performance at selected locations, also demonstrated the superiority of the GRU model, for all time steps, with Willmott's index (WI) values generally above 0.9 and high reliability as reflected in Prediction Interval Coverage Probability (PICP) values mostly exceeding 90 %. The results, however, weren't always perfect; both the GRU and LSTM models encountered limitations with forecasting the sea level maxima. Further examination of the spatial discrepancies also reveals some problematic areas in the eastern Gulf of Finland. This may have been influenced by the exclusion of some input components such as river discharge, salinity and meridional winds, further enhanced by complex hydrodynamics, extreme sea level variations, strong local currents, resonance-induced seiches and seasonal ice cover. In addition, an external validation of the GRU results was performed using along-track satellite altimetry from Sentinel 3A and","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104496"},"PeriodicalIF":4.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579608","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}

{"title":"Design and performance of an open-circuit marine icing wind tunnel","authors":"Matthew Garvin ,&nbsp;Adam Kirchhefer","doi":"10.1016/j.apor.2025.104510","DOIUrl":"10.1016/j.apor.2025.104510","url":null,"abstract":"<div><div>Marine icing presents a challenge for ship and floating structure operations in high latitudes. Without mitigation, ice accumulation can lead to structural damage and loss of stability. This problem is not new but there has been renewed interest in icing mitigation in recent years as shipping and resource exploration have pushed towards the poles. To investigate the phenomena associated with marine icing, an open-circuit icing wind tunnel was built with the express goal of evaluating coatings designed to mitigate ice accretion on marine structure topsides including flat and tubular shapes. The wind tunnel was designed to provide wind speeds up to 15 m/s in air temperatures as low as −22 °C. A system was devised to introduce fresh or salt water into the wind tunnel to simulate of freezing spray or heavy precipitation.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104510"},"PeriodicalIF":4.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593202","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}

{"title":"Seismic performance of revetment breakwater and nearby frame structure on reclaimed coral sand foundation in the SCS: Centrifuge shaking table test","authors":"Kunpeng He ,&nbsp;Jianhong Ye ,&nbsp;Linjian Ma ,&nbsp;Bin Fang","doi":"10.1016/j.apor.2025.104512","DOIUrl":"10.1016/j.apor.2025.104512","url":null,"abstract":"<div><div>In the past decade, several artificial lands have been constructed on the top of several natural coral reefs by the way of reclamation of coral sand in the South China Sea (SCS). To protect and utilize these reclaimed lands, a few revetment breakwaters, as well as some frame structures had been constructed along the margins of or on these reclaimed lands. Taking the reclamation project on coral reefs as the engineering background, three centrifuge shaking table tests were conducted to explore the seismic responses of these reclaimed coral sand foundation (CSF), and to evaluate the stability of the revetment breakwater, as well as a nearby frame structure. It is indicated by these physical model tests that the reclaimed CSF has a considerable amplification effect on the seismic acceleration, and this amplification effect is positively correlated to the located altitude. No residual liquefaction occurs in the CSF during earthquake excitation. The maximum residual displacement of the breakwater is about 4 mm in horizontal, while the maximum residual settlement of the frame structure is only 1 mm in the scale of centrifuge. It is judged that the breakwater and the frame structure are in a relatively stable state. Based on the results from comparative research, it is observed that pore pressure is more likely to residually build up, and the amplification effect of acceleration is more obvious in less dense CSF, causing the stability of breakwaters or other structures on coral reef to be relatively poor.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104512"},"PeriodicalIF":4.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593204","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}

{"title":"Hybrid path planning framework to integrate improved A*-DWA algorithms for enhancing path safety and efficiency","authors":"Hee-Mun Park ,&nbsp;Seung-Wan Cho ,&nbsp;Kyung-Min Seo","doi":"10.1016/j.apor.2025.104497","DOIUrl":"10.1016/j.apor.2025.104497","url":null,"abstract":"<div><div>As the deployment of Unmanned Surface Vehicles (USVs) expands across various sectors, the importance of safe and efficient path planning systems is increasingly underscored, particularly in fields such as maritime safety and national security where high levels of navigational efficiency and safety are demanded. While previous path planning research often focused on either safety or efficiency, this study proposes an improved path planning framework that considers both aspects simultaneously, overcoming the limitations of traditional Global Path Planning (GPP) and Local Path Planning (LPP) to enhance route safety, efficiency capabilities. The proposed framework comprises GPP with Safety Areas (GPP-SA) and LPP with Goals &amp; Obstacles (LPP-GO). The proposed structure ensures that the USV can navigate safely and efficiently in a variety of environments and reach its destination easily. The framework has been evaluated through various experiments, including scenario-based validation and statistical verification, demonstrating its superiority by integrating and improving upon existing methods. The findings of this research explore the feasibility of applying these advancements in real maritime environments, making a significant contribution to the realization of safe and efficient path planning in unmanned maritime and ship navigation systems.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104497"},"PeriodicalIF":4.3,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579607","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}

{"title":"Dynamic analysis and uncertainty modeling of viscoelastic beam response to fluid stimulation: Insights into nonlinear effects and velocity uncertainties","authors":"Mousa Rezaee ,&nbsp;Reza Fathi ,&nbsp;Vahid Arab Maleki","doi":"10.1016/j.apor.2025.104487","DOIUrl":"10.1016/j.apor.2025.104487","url":null,"abstract":"<div><div>This study investigates nonlinear vibrations in viscoelastic beams induced by external fluid flow. We introduce novel equations considering the Kelvin-Voigt viscoelastic model, geometric nonlinearity, and uncertainties in flow velocity for a more realistic analysis. A notable aspect of this work is the introduction of uncertainties in fluid flow velocity to enhance the realism of assumptions when estimating fluid forces acting on the structure. The nonlinear equation of motion acquired by using the second law of Newton and discretized by implementing the Galerkin technique. Then, the influence of fluid velocity and viscoelastic parameters on dynamic behavior and vibration behavior of the system are studied. Considering the uncertainties in fluid force, the statistical analysis using the Monte Carlo method reveals significant effects of uncertainties on system vibrations. Uncertainties in fluid velocity notably affect the acceleration amplitude, and show a noticeable increase in the lock-in area. This emphasizes the importance of considering fluid velocity uncertainty in designing such structures for optimal performance and structural integrity.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104487"},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552009","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}

{"title":"Data driven multi-objective optimization of the scheduling for towing a floating offshore wind turbine between assembly port and installation location throughout a year","authors":"Frédéric Le Pivert ,&nbsp;Adam Roberts ,&nbsp;Adán López-Santander ,&nbsp;Matthew J. Craven ,&nbsp;Saeid Kazemi","doi":"10.1016/j.apor.2025.104492","DOIUrl":"10.1016/j.apor.2025.104492","url":null,"abstract":"<div><div>High demand for the installation of floating offshore wind turbines over the coming years is likely to place significant pressure on ports and installation vessels. Optimization of the routes between ports and farms and the towing schedule when transporting equipment is therefore critical to reducing operation timescales and carbon emissions. This paper presents two series of multi-objective optimizations for minimizing the timescale and carbon emissions for the case of an IEA 15 MW turbine on a VolturnUS-S platform being wet towed through the English Channel to the Celtic Sea. The study makes use of the Maritime Simulation Laboratory (MSL) Ship Simulator to develop an empirical model of the floating offshore wind turbine being towed under different wind conditions. This is then combined with bathymetry data and historical metocean data from the year 2021 to perform the optimizations. The optimization results are used to feed a second optimization that creates a schedule reducing both emissions and cumulated towing time during a whole year for different number of floating offshore wind turbines.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"157 ","pages":"Article 104492"},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551999","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}