Applied Ocean Research最新文献

{"title":"Numerical study on propeller flow field in four quadrants","authors":"Suli Lu ,&nbsp;Wim Van Hoydonck ,&nbsp;Santiago Lopez Castaño ,&nbsp;Evert Lataire ,&nbsp;Guillaume Delefortrie","doi":"10.1016/j.apor.2025.104576","DOIUrl":"10.1016/j.apor.2025.104576","url":null,"abstract":"<div><div>The propeller hydrodynamic performance under different direction combinations of the uniform inflow and the propeller rate, i.e. four quadrants (Q1–Q4) conditions, is studied with CFD methods, and validated by the experimental data of a model-scale propeller. The numerical strategies including the turbulence model, the grid size, and the time step are discussed. Regarding the relative direction of the inflow and the propeller jet, RANS (Reynolds-Averaged Navier–Stokes) and DDES (Delayed Detached Eddy Simulation) are compared in resolving global and local flow quantities. RANS results show similar near-field flow fields to DDES results in Q1/Q3, while DDES gives more accurate forces and richer flow details such as vortex resolutions for cases with opposite flow directions. Then the propeller is simulated by RANS in Q1/Q3, and by DDES in Q2/Q4. In four quadrants, the propeller thrust and torque, vortex structures, and velocity and pressure distributions are presented for flow mechanism analysis. In Q1/Q3 conditions, the propeller jet evolves in the same direction as the inflow, promising a converged flow field. In Q3, the reverse rotation leads to less significant flow acceleration effects than Q1 under the same inflow velocity, and the non-uniformity of pressure distributions on the blades is strengthened. For Q2/Q4, massive flow separations occur due to the interaction of the propeller jet and counter inflow, and the recirculation zone with reversed axial velocities forms. With increased inflow velocities, the dominant role between the inflow and the propeller jet gradually shifts, and the difference in the propeller jet produced by ahead and astern rotations postpones the shift in Q2 compared with Q4. This study investigates the propeller flow field in four quadrants and can help to quantify rudder inflow variations in hull-propeller-rudder interactions for future research.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104576"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886460","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":"Surf and swash zone hydrodynamics forced by oblique, monochromatic waves in a wave basin with a smooth, impermeable beach","authors":"Alexandra E. Schueller ,&nbsp;Kelsey Fall ,&nbsp;Hyungyu Sung ,&nbsp;Ryan P. Mulligan ,&nbsp;Jason Olsthoorn ,&nbsp;Nimish Pujara ,&nbsp;Patricia Chardón-Maldonado ,&nbsp;Rafiu Oyelakin ,&nbsp;Jack A. Puleo","doi":"10.1016/j.apor.2025.104558","DOIUrl":"10.1016/j.apor.2025.104558","url":null,"abstract":"<div><div>Beaches are coastal features that offer economic benefits, ecosystem services, and natural barriers against flooding. Sustainable management of beaches requires a firm understanding of hydrodynamics and sediment transport processes. This experimental study reports on surf and swash zone hydrodynamics, forced by oblique, monochromatic waves with heights of 0.15 m, 0.20 m, and 0.25 m and periods of 2.0 s and 2.5 s, approaching a smooth impermeable beach with three different offshore incident angles (5°, 10°, 15°). Fluid velocities and bed shear stress were separated into cross-shore and alongshore directions. The data were analyzed using a triple decomposition isolating the time-averaged flow from the wave-driven flow and turbulence in each wave cycle. The velocities showed variations for different wave incident angles and cross-shore positions. The cross-shore velocities were skewed-asymmetric with steep wave fronts and velocity magnitudes reaching nearly 0.5 m/s. The cross-shore bed shear stress magnitude peaked during the start of each wave cycle reaching up to 18 N/m². Alongshore flows remained relatively uniform during the wave cycle, with typical velocities up to 0.5 m/s. There was a non-monotonic variation of alongshore velocities with wave angle, with waves forced at 10° often exhibiting the largest alongshore velocities compared to waves forced at 15° These variations were likely due to variations in wave breaking location relative to fixed in situ sensors. Alongshore bed shear stress magnitudes peaked at the beginning of the wave cycle with values between 0.8 and 4.5 N/m² depending on forcing conditions. The alongshore flow and bed shear stress were dominant during flow reversal when cross-shore velocities were near zero, even for small wave angles. These findings highlight the potential importance of alongshore processes on resultant bed shear stress and sediment and solute transport.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104558"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886461","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":"Study on the attenuation effect of pressure wave by bubble clusters using the compressible multi-scale method","authors":"Li-Lei Zhan,&nbsp;Cheng Zheng,&nbsp;Shi-Ping Wang,&nbsp;Shi-Min Li,&nbsp;A-Man Zhang","doi":"10.1016/j.apor.2025.104579","DOIUrl":"10.1016/j.apor.2025.104579","url":null,"abstract":"<div><div>Bubble clusters are widely existed in nature and every single bubble will pulsate under its surrounding ambient pressure wave. To simulate the motion of bubble cluster under pressure wave is a great challenge for both algorithm robustness and calculation cost. This paper introduces a multi-scale method to simulate interaction between the pressure wave and bubble clusters comprising several thousand natural bubbles. In this model, the propagation process of pressure waves is simulated within a continuous Eulerian field, while the bubble clusters are depicted as Lagrangian points distributed in this field. The flow field information surrounding the bubbles is acquired by interpolation from the Eulerian field. Bubble oscillation and migration are accurately calculated using bubble theory. The variations of the bubble clusters are incorporated as source terms in the equations to achieve two-way coupling solution, which facilitates a more precise simulation of the interaction between underwater pressure waves and bubble clusters. Comparison with experimental data demonstrates the advantages and effectiveness of the computational model in simulating bubble cluster coupled with underwater pressure wave. Subsequently, this paper investigates the propagation process and attenuation mechanism of pressure waves among bubble clusters, analyzing the effects of pressure wave amplitudes and bubbles numbers and bubble sizes on pressure wave attenuation. Our results indicate that the pressure wave attenuation is dominated by the initial gas volume fraction of the bubble cluster and is not significantly affected by the pressure wave amplitude.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104579"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886452","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":"Scour near low-crested breakwaters: review and technical challenges","authors":"Francisco Pinto ,&nbsp;Paulo Rosa-Santos ,&nbsp;Javier L. Lara ,&nbsp;Victor Ramos","doi":"10.1016/j.apor.2025.104582","DOIUrl":"10.1016/j.apor.2025.104582","url":null,"abstract":"<div><div>Low-crested breakwaters are widely used structures for coastal protection, but they are vulnerable to scouring caused by wave and current action. This paper analyses information from available mobile bed physical models, the progress made in recent years on numerical modelling alongside the major limitations of the developed models and the available formulations for scour hole prediction and protection design. Physical modelling has been the primary approach for studying scour processes around low-crested breakwaters. However, existing scour depth prediction formulations have limited applicability to these structures due to their geometric characteristics. Gaps in current research include uncertainties derived from the use of scaling laws for mobile bed physical models, the effects of plunging breakers on the evolution of scour phenomena, and challenges arising from the permeability and crest freeboard of the structure and its effect on the quantification of scour phenomena. Furthermore, there is a need to investigate the impact of the slope angle, water depth, crest freeboard and wave characteristics on the scour hole evolution, as well as to optimise scour protection elements in terms of their geometric characteristics. Moreover, this review emphasises the importance of using integrated methodologies combining physical and numerical modelling with monitoring data, to comprehensively understand scour phenomena and develop mitigation measures.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104582"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900092","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":"CFD-based design of novel drag-reducing appendages for container ships","authors":"Ryan Torckler,&nbsp;Hamed Majidiyan,&nbsp;Hossein Enshaei","doi":"10.1016/j.apor.2025.104605","DOIUrl":"10.1016/j.apor.2025.104605","url":null,"abstract":"<div><div>Container ships, as cornerstones of modern global trade, have significantly increased in size in recent years. This growth necessitates minimizing resistance to environmental forces to improve operability, enhance safety, and reduce fuel consumption. While aerodynamic optimization has traditionally focused on windshields and container stacking configurations, this study introduces a novel drag-reducing appendage inspired by sports aerodynamics engineering. The research follows a two-stage approach. First, a numerical model was validated against experimental wind tunnel results, achieving a high correlation with less than a 2 % difference in drag coefficient. Second, the validated model was used in computational fluid dynamics (CFD) simulations to assess the effectiveness of various appendage designs. A parametric study was conducted to optimize appendage placement, size, and orientation, leading to two configurations that achieved maximum drag reductions of 9.47 % and 9.22 %, respectively. Results indicate that these appendages mitigate adverse pressure effects and streamline flow around the accommodation block, effectively reducing aerodynamic drag. This study demonstrates the feasibility of integrating simple, cost-effective appendages to enhance the aerodynamic performance of post-panamax container ships without compromising cargo capacity. The findings provide a practical approach for reducing fuel consumption and emissions, supporting ongoing efforts toward sustainable shipping.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104605"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931569","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":"A spectral fatigue damage prediction model for offshore structures under Gaussian random processes based on bimodal spectra","authors":"Yanshuo Liu,&nbsp;Hongxia Li,&nbsp;Gang Liu,&nbsp;Yi Huang","doi":"10.1016/j.apor.2025.104588","DOIUrl":"10.1016/j.apor.2025.104588","url":null,"abstract":"<div><div>Offshore structures frequently confront complex and variable marine environments, and the frequency-domain approach is often used in engineering to predict the fatigue damage of structures. To bridge the gap between stress spectra and stress range distributions, this paper proposes a novel stress range probability density distribution model comprising two stress range distribution functions, which can be well adapted to the shapes of the stress power spectral density (PSD) in various cases, and provides a more accurate representation of the rain-flow range probability density function (PDF). This study initially analyzes the stress range distributions of bimodal spectra using the rain-flow counting RFC method. Subsequently, and the unknown parameters of the stress range PDF are determined using the 1st-order moment of rain-flow stress amplitudes and polynomial relationships derived from normalized mean frequency and shape parameters. The proposed model is validated through the use of stress time-series data generated from random combinations of normal distribution functions.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104588"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921817","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":"Effect of nonlinear hydrodynamics on global dynamic responses of a semi-submersible wind turbine","authors":"Haoran Li,&nbsp;Jinhai Zheng,&nbsp;Jisheng Zhang,&nbsp;Wei Peng,&nbsp;Linlong Tong,&nbsp;Xuan Zhang","doi":"10.1016/j.apor.2025.104600","DOIUrl":"10.1016/j.apor.2025.104600","url":null,"abstract":"<div><div>The natural frequencies of rigid body motion of a semi-submersible wind turbine are outside the linear wave-excitation range and can be excited by nonlinear hydrodynamics, which significantly increases the low-frequency dynamic responses. The difference-frequency wave force quadratic transfer functions (QTFs) and the frequency-dependent added mass and damping around the natural frequencies of rigid body motions of the OC4-DeepCwind semi-submersible wind turbine estimated from the potential flow theory in a time-domain coupled numerical model of wind turbine (OpenFAST) are modified based on a series of computational fluid dynamic (CFD) simulations in the current research. The dynamic responses of wind turbine under three groups of wave and wind conditions are investigated using the numerical models with different combinations of nonlinear hydrodynamics. The low-frequency components of the responses which include the surge motions, pitch motions, tower base bending moments and mooring line tensions increase by at least 50 % under irregular wave conditions when the difference-frequency wave force QTFs are modified. However, under the irregular wave and turbulent wind conditions, this increment will reduce, especially for the surge motions and upwind mooring line tensions. The effect of the difference-frequency wave force QTFs is negligible under turbulent wind conditions. The modified frequency-dependent damping leads to a decreasing in the low-frequency components of all responses under all wind and wave conditions, and this reduction will be up to 50 %. In addition, the modified frequency-dependent added mass has no influence on the resonance frequencies.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104600"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069549","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":"Corrigendum to “Leveraging Distributed Acoustic Sensing for monitoring vessels using submarine fiber-optic cables” [Applied Ocean Research, Volume 154, January 2025]","authors":"Bob Paap ,&nbsp;Vincent Vandeweijer ,&nbsp;Jan-Diederik van Wees ,&nbsp;Dirk Kraaijpoel","doi":"10.1016/j.apor.2025.104559","DOIUrl":"10.1016/j.apor.2025.104559","url":null,"abstract":"","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104559"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072697","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":"Design and global analysis of two floating wind turbines in a shared mooring line configuration","authors":"Chern Fong Lee,&nbsp;Muk Chen Ong,&nbsp;Hammad Munir","doi":"10.1016/j.apor.2025.104602","DOIUrl":"10.1016/j.apor.2025.104602","url":null,"abstract":"<div><div>Shared mooring configurations for floating offshore wind turbines (FOWTs) offer a promising solution to significantly reduce the overall costs of wind farms. This study presents a detailed framework for analyzing FOWTs utilizing a shared mooring line configuration. A case study involving two 5-MW CSC FOWTs connected by a single shared mooring line is selected. First, excursion circles are used to characterize platform offsets for the shared mooring line system (SM) under steady wind loads from all directions. Next, dynamic responses—including platform motions, wind turbine tower bending moments, and mooring line tensions—are evaluated for the SM under irregular wave and turbulent wind conditions corresponding to a 50-year return period, while accounting for the full directionality of environmental loads. The results are benchmarked against those of an individual mooring system (IM). The analysis confirms the viability of the SM configuration, with only a 5 % increase in the maximum mooring line utilization factor compared to the IM. However, the SM exhibits significantly larger horizontal offsets, with the maximum offsets of the FOWTs more than double those observed in the IM. When the wind turbines are operational, the higher mean surge offsets in the SM lead to increased mean tension levels, making the anchor line tensions more sensitive to wave-frequency excitations. Despite these challenges, the SM configuration demonstrates strong economic potential, achieving an estimated 20 % reduction in mooring costs compared to the IM.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104602"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931567","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":"Numerical investigations on the hydrodynamic performance of different configurations of oscillating water columns","authors":"S. Sandana Socrates ,&nbsp;V. Sriram ,&nbsp;V. Sundar","doi":"10.1016/j.apor.2025.104599","DOIUrl":"10.1016/j.apor.2025.104599","url":null,"abstract":"<div><div>Among the array of wave energy converters (WEC) under scrutiny, oscillating water columns (OWC) have emerged as one of the most thoroughly researched and straightforward options. This study delves into the hydrodynamic performance characteristics of four distinct configurations of OWC operating in regular and random wave conditions. Specifically, it examines the FD-OWC (Forward Duct OWC), CFLW-OWC (Curved Front Lip Wall OWC), CVFLW-OWC (Curved Vertical Front Lip Wall), and CEFLW-OWC (Curved Edged Front Lip Wall OWC), each featuring variations in the design of the front lip wall. The three-dimensional numerical model based on the open-source computational fluid dynamics package (OpenFOAM) is adopted to investigate the hydrodynamic performance of OWC devices. The numerical results are validated with the existing experimental works. The influence of the wave amplification factor, wave power absorption coefficient, the air pressure inside the four types of OWC chambers, the hydrodynamic efficiency, and dynamic water pressure inside and outside the front lip walls of the chambers for each of the configurations are computed. The results show that the CEFLW-OWC exhibits the maximum hydrodynamic efficiency.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104599"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931568","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}