Applied Ocean Research最新文献

{"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}

{"title":"Enhancement effect of casing on underwater explosion shock wave and bubble","authors":"Zhifan Zhang ,&nbsp;Jingyuan Zhang ,&nbsp;Hailong Li ,&nbsp;Gangwei Liu ,&nbsp;Longkan Wang ,&nbsp;Guiyong Zhang","doi":"10.1016/j.apor.2025.104592","DOIUrl":"10.1016/j.apor.2025.104592","url":null,"abstract":"<div><div>The casing is a critical design factor for underwater weapons, significantly influencing the energy output of underwater explosion (UNDEX) charges. In this study, a numerical model for cased charge UNDEX was developed using the coupled Eulerian-Lagrangian (CEL) method. To optimize the shock wave and bubble energy outputs, the effects of the thickness ratio <em>n</em> and casing material on load characteristics were systematically investigated, and optimal parameters were derived. First, the enhancement effects of the thickness ratio <em>n</em> on shock wave and bubble loads were examined at varying distance parameters <em>δ</em>. Subsequently, the influence of <em>n</em> on the spatial distribution of shock wave and bubble loads was analyzed using a two-way analysis of variance (ANOVA) model. Four typical underwater weapon casing materials - Ti6%Al4%V, Cu-OFHC, Al 6061-T6, Q235 - were selected. Their impacts on key parameters, including peak shock wave overpressure, bubble radius, bubble period, bubble shape, and pulsation pressure, were thoroughly evaluated. This study aims to elucidate the spatial and temporal evolution laws of shock wave and bubble loads for different types of cased charges, providing insights into the design and optimization of underwater weapons.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104592"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143911513","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":"Evaluation of a novel design of floating net cage with hybrid side and bottom nets in current","authors":"Zhi Wang ,&nbsp;Shuai Niu ,&nbsp;Can Cui ,&nbsp;Tianyu Gu ,&nbsp;Fuxiang Hu ,&nbsp;Dejun Feng ,&nbsp;Xiaoyu Qu","doi":"10.1016/j.apor.2025.104563","DOIUrl":"10.1016/j.apor.2025.104563","url":null,"abstract":"<div><div>The floating cage system is the dominant technology used for marine aquaculture. While traditional HDPE cages with fiber nets have been extensively studied, it is important to highlight that research on the performance of floating cages equipped with metal nets, as well as those with hybrid metal-fiber nets, remains relatively limited. Based on flume experiments, we mainly investigated the net deformation and drag force of the square and octagonal cages featured with hybrid side and bottom nets in currents, together with the effect of bottom weight. The results indicate that increasing bottom weight effectively reduced cage deformation at lower flow velocities but became less effective at higher velocities, where the influence of flow velocity on drag was more significant. The use of a metal bottom net had a limited impact on cage performance, primarily due to the alignment of the bottom frame parallel to the water flow. Both HN-FN (hybrid fiber-wire and fiber net) and WN-FN (wire and fiber net) cages retain a similar volume of over 60 % at high flow velocities. However, the drag on WN-FN cages is significantly higher than that on HN-FN cages, indicating that the HN-FN configuration offers a more advantageous balance between structural stability and reduced drag under high flow conditions. Octagonal cages consistently outperform square cages at both lower and higher flow velocities, particularly excelling at higher velocities. However, square cages offer distinct advantages, such as simpler construction, easier maintenance, and improved water exchange. Moreover, the bottom frame and vertical wire ropes effectively regulate cage deformation and preserve structural integrity. These findings can provide valuable guidelines and recommendations for optimizing net system design to enhance performance under diverse flow conditions.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104563"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894877","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":"Wave family climatology of the U.S. East and Gulf Coasts","authors":"Maria Venolia,&nbsp;Reza Marsooli","doi":"10.1016/j.apor.2025.104593","DOIUrl":"10.1016/j.apor.2025.104593","url":null,"abstract":"<div><div>The dynamic complexity of the sea surface, characterized by the simultaneous presence of multiple wave systems, necessitates a detailed analysis beyond the scope of traditional integrated bulk wave parameters, which, in the case of multimodal seas, can provide inaccurate information. This research leverages spectral techniques to identify wave system populations - referred to as wave families - in order to investigate wave climatology along the U.S. East and Gulf coasts. Utilizing in-situ directional spectral buoy measurements from NOAA's National Data Buoy Center, the frequency-direction wave spectra are constructed using the maximum entropy method. The wave spectra are then partitioned into wave systems using the watershed algorithm, enabling the generation of the occurrence distribution of the spectral partitions’ peak energy density. The occurrence distribution at each buoy location is further partitioned to identify predominant wave families, each one with unique meteorological and geographical origins. Our analysis presents notable spatiotemporal variability in wave family characteristics, such as wave family significant wave height, wave period, and directional range, across different buoy locations and seasons, thus accentuating the complexity of wind-generated waves and their potential implications on coastal dynamics.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104593"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903885","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 fluid-structure interaction vibration and bandgap properties of periodic composite hydraulic pipes","authors":"Fuming Zhou ,&nbsp;Jian Liao ,&nbsp;Lin He ,&nbsp;Zongbin Chen ,&nbsp;Xiaopeng Tan ,&nbsp;Yundong Liang","doi":"10.1016/j.apor.2025.104587","DOIUrl":"10.1016/j.apor.2025.104587","url":null,"abstract":"<div><div>This research incorporates the Bragg scattering mechanism in phononic crystal theory into fluid-structure interaction vibration suppression of hydraulic pipes. Based on steel pipes and hydraulic composite hoses, a periodic composite hydraulic pipe structure is developed, and its vibration and bandgap properties are investigated. Firstly, based on the anisotropic laminated shell theory, fluid dynamic equations and fluid-structure interaction boundary conditions, the one-dimensional fluid-structure interaction axial and transverse vibration models of the hydraulic composite hoses are derived. This model is compatible with the classical fluid-structure interaction model; specifically, when the pipe material is steel, it degenerates into the classical fluid-structure interaction 8-equation model. Secondly, the transfer matrix is constructed using the Laplace-characteristics method to solve the fluid-structure interaction model of the steel and hose-based periodic composite hydraulic pipes. By incorporating the Bloch wave vector theorem, the bandgaps and frequency response functions of the composite pipes are determined. The accuracy of the proposed method is validated by comparing the results with those from finite element simulations. On this basis, the influence of the fluid-structure interaction effect on bandgaps and vibration properties is investigated. Numerical results indicate that in the axial direction, Poisson coupling modulates the pulsation pressure and vibration wave vectors to form new bandgaps, while friction coupling has minimal impact on bandgaps but dissipates high-frequency vibration energy. In the transverse direction, the mass and inertia effects of the fluid shift the vibration bandgaps towards lower frequencies. Finally, the effects of fluid and pipe parameters on axial and transverse vibration bandgaps are examined. This research provides a novel and effective approach for vibration suppression in hydraulic pipes and offers valuable theoretical guidance for the engineering design of periodic composite hydraulic pipes.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104587"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900084","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":"Novel temperature-chain drifter for enhanced upper-ocean temperature observation","authors":"Jiangyan Fan ,&nbsp;Shuangxi Guo ,&nbsp;Chenjing Shang ,&nbsp;Pengqi Huang ,&nbsp;Guanghui Han ,&nbsp;Shengqi Zhou ,&nbsp;Xiaodong Shang","doi":"10.1016/j.apor.2025.104581","DOIUrl":"10.1016/j.apor.2025.104581","url":null,"abstract":"<div><div>This study introduces a novel temperature-chain drifter designed to address observational gaps in upper-ocean thermal monitoring. The system combines a self-stabilizing buoy with meteorological sensors, a sea surface conductivity-temperature-depth (CTD) instrument, and a Kevlar-reinforced coaxial temperature chain capable of high-resolution vertical profiling (0–300 m). Real-time positioning and data transmission are achieved via BeiDou/Iridium satellite telemetry, while a solar-energy module ensures uninterrupted operation during observation period. This drifter was tested in a 30-day field deployment in the northern South China Sea with 20-minute sampling intervals and 80 % data transmission success. The results indicate that the drifter’s motion is driven by mesoscale eddy advection, inertial oscillations, tidal forcing, and internal waves. Temperature spectra from the drifter indicate the upper-ocean temperature is modulated by diurnal cooling, tides and internal waves. The advancements of this temperature-chain drifter establish a new paradigm for multi-parameter observation platforms, and it is particularly valuable for capturing dynamic processes in the upper ocean and air-sea interactions, especially during extreme weather events.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"158 ","pages":"Article 104581"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894870","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}