Pub Date : 2026-03-01Epub Date: 2026-02-19DOI: 10.1016/j.apor.2026.104985
Hunter Boswell , Frank D. Han , Gaurav Savant , Guirong Yan , Wouter Mostert
Current engineering standards lack the ability to predict the peak impact forces of breaking waves impinging directly upon coastal structures. In this study solitary waves impacting vertical and tapered walls are investigated. To capture the detailed physics of the wave profile that impacts the wall, two-dimensional direct numerical simulations are applied to model the wave traveling over a simplified bathymetry consisting of an initially uniform depth, followed by a uniform beach ramp and then terminating in a uniform depth inshore region and vertical wall. Such an approach can simulate wave runup on land and then the impact with the vertical or tapered walls. The wall location in the bathymetry was varied to simulate different types of wave impacts, including non-breaking, plunging, and bores. The resulting wave characteristics and wall impact pressures were compared across these varying regimes. The associated wave impact force was extracted and compared to various standards used in coastal engineering, and severe underestimation has been found for plunging and weak plunging type impacts. To address this, in this study, a dimensionless distance parameter has been proposed to provide a unifying trend in regards to the peak impact forcing across the various impact types.
{"title":"Applying direct numerical simulations to investigate wave forcing against a vertical wall","authors":"Hunter Boswell , Frank D. Han , Gaurav Savant , Guirong Yan , Wouter Mostert","doi":"10.1016/j.apor.2026.104985","DOIUrl":"10.1016/j.apor.2026.104985","url":null,"abstract":"<div><div>Current engineering standards lack the ability to predict the peak impact forces of breaking waves impinging directly upon coastal structures. In this study solitary waves impacting vertical and tapered walls are investigated. To capture the detailed physics of the wave profile that impacts the wall, two-dimensional direct numerical simulations are applied to model the wave traveling over a simplified bathymetry consisting of an initially uniform depth, followed by a uniform beach ramp and then terminating in a uniform depth inshore region and vertical wall. Such an approach can simulate wave runup on land and then the impact with the vertical or tapered walls. The wall location in the bathymetry was varied to simulate different types of wave impacts, including non-breaking, plunging, and bores. The resulting wave characteristics and wall impact pressures were compared across these varying regimes. The associated wave impact force was extracted and compared to various standards used in coastal engineering, and severe underestimation has been found for plunging and weak plunging type impacts. To address this, in this study, a dimensionless distance parameter has been proposed to provide a unifying trend in regards to the peak impact forcing across the various impact types.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"168 ","pages":"Article 104985"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403058","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}
Pub Date : 2026-03-01Epub Date: 2026-02-23DOI: 10.1016/j.apor.2026.104984
Umberto Sasso , Gaetano Porcile , Octavio E. Sequeiros , Carlos Pirmez , Michele Bolla Pittaluga
This study investigates the conditions required for self-acceleration in laboratory-scale turbidity currents using a numerical model validated against experimental measurements. A series of simulations were conducted to isolate the main hydro-sedimentary factors potentially controlling the onset and sustenance of flow self-acceleration. Specific depositional processes, namely the vertical and lateral grain size composition of the turbidites formed by antecedent turbidity currents were found to affect the dynamics of subsequent flow events. Results show that simplified bed representations fail to reproduce self-accelerating regimes, demonstrating that an erodible bed is a necessary but not sufficient condition for a current to self-accelerate. In contrast, when the modelled bed exhibits realistic sedimentary features, such as bed slope increase due to cumulative deposition, downstream sediment fining, and vertical stratification, flows accelerate due to enhanced sediment entrainment. These findings underscore the critical role of past flow deposits in actively preconditioning the nature of future events.
{"title":"How depositional processes in turbidite deposits affect the self-acceleration of turbidity currents","authors":"Umberto Sasso , Gaetano Porcile , Octavio E. Sequeiros , Carlos Pirmez , Michele Bolla Pittaluga","doi":"10.1016/j.apor.2026.104984","DOIUrl":"10.1016/j.apor.2026.104984","url":null,"abstract":"<div><div>This study investigates the conditions required for self-acceleration in laboratory-scale turbidity currents using a numerical model validated against experimental measurements. A series of simulations were conducted to isolate the main hydro-sedimentary factors potentially controlling the onset and sustenance of flow self-acceleration. Specific depositional processes, namely the vertical and lateral grain size composition of the turbidites formed by antecedent turbidity currents were found to affect the dynamics of subsequent flow events. Results show that simplified bed representations fail to reproduce self-accelerating regimes, demonstrating that an erodible bed is a necessary but not sufficient condition for a current to self-accelerate. In contrast, when the modelled bed exhibits realistic sedimentary features, such as bed slope increase due to cumulative deposition, downstream sediment fining, and vertical stratification, flows accelerate due to enhanced sediment entrainment. These findings underscore the critical role of past flow deposits in actively preconditioning the nature of future events.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"168 ","pages":"Article 104984"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403061","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}
Pub Date : 2026-03-01Epub Date: 2026-02-14DOI: 10.1016/j.apor.2026.104978
Xingkun Xu , Kaushik Sasmal , Pavel Tkalich
We investigate the seasonal, interannual, and long-term behaviour of waves in and around the Malacca–Singapore Strait using a nested, high-resolution WAVEWATCH III hindcast forced by 8-km downscaled ERA5 through SINGV-RCM for 1981–2014, rigorously validated against multi-mission altimetry. The regional climatology features a persistent offshore–inshore gradient shaped by fetch alignment and bathymetry, with the most energetic conditions in boreal winter. Interannually, significant wave height anomalies are positively linked to ENSO and organize into a winter dipole that enhances waves in the straits while weakening or reversing the response east of Singapore; this structure is captured by a dominant, in-phase leading EOF (explaining the vast majority of interannual variance) and a secondary cross-shore mode governed by directional winds and island/topographic sheltering. Long-term tendencies indicate a modest rise in mean wave conditions from spring to autumn alongside a wintertime weakening of extremes over the eastern shelf, indicating a redistribution of risk from rare peaks toward more frequent moderate states. Generalized extreme-value analysis provides a coherent exposure gradient in present-climate design levels, with 100-year significant wave heights reaching m on the outer shelf and substantially lower values in the straits ( m) and harbours ( m). Thus, these mechanism-consistent diagnostics provide exposure-aware guidance for navigation, port operations, and coastal design in the Singapore region.
{"title":"High-resolution wave climate analysis in complex tropical straits using triple-nested unstructured WW3 modeling","authors":"Xingkun Xu , Kaushik Sasmal , Pavel Tkalich","doi":"10.1016/j.apor.2026.104978","DOIUrl":"10.1016/j.apor.2026.104978","url":null,"abstract":"<div><div>We investigate the seasonal, interannual, and long-term behaviour of waves in and around the Malacca–Singapore Strait using a nested, high-resolution WAVEWATCH III hindcast forced by 8-km downscaled ERA5 through SINGV-RCM for 1981–2014, rigorously validated against multi-mission altimetry. The regional climatology features a persistent offshore–inshore gradient shaped by fetch alignment and bathymetry, with the most energetic conditions in boreal winter. Interannually, significant wave height anomalies are positively linked to ENSO and organize into a winter dipole that enhances waves in the straits while weakening or reversing the response east of Singapore; this structure is captured by a dominant, in-phase leading EOF (explaining the vast majority of interannual variance) and a secondary cross-shore mode governed by directional winds and island/topographic sheltering. Long-term tendencies indicate a modest rise in mean wave conditions from spring to autumn alongside a wintertime weakening of extremes over the eastern shelf, indicating a redistribution of risk from rare peaks toward more frequent moderate states. Generalized extreme-value analysis provides a coherent exposure gradient in present-climate design levels, with 100-year significant wave heights reaching <span><math><mrow><mo>∼</mo><mn>6</mn></mrow></math></span> m on the outer shelf and substantially lower values in the straits (<span><math><mrow><mo>∼</mo><mn>3</mn></mrow></math></span> m) and harbours (<span><math><mrow><mo>∼</mo><mn>1</mn></mrow></math></span> m). Thus, these mechanism-consistent diagnostics provide exposure-aware guidance for navigation, port operations, and coastal design in the Singapore region.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"168 ","pages":"Article 104978"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403105","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}
Pub Date : 2026-03-01Epub Date: 2026-02-19DOI: 10.1016/j.apor.2026.104986
Jiaqi Chen, Yao Jiang, Mengcheng Wang
This study employs three-dimensional numerical simulations to investigate scour development on a sand bed induced by a translating vertical circular jet. Simulations were performed for jet exit velocities from 2 to 4 m/s and nozzle translation speeds from 0.05 to 0.2 m/s. The results show that nozzle translation rapidly terminates local erosion at previous impingement locations, while the induced horizontal momentum enhances downstream bedload mobility and allows limited suspended sediment transport. Sediment transport evolves through four stages, and the scour geometry transitions from an initially circular cavity to a ribbon-like depression with a spoon-shaped transport zone. The scour pit exhibits three characteristic sections, including an initial section that grows rapidly with increasing exit velocities, a stable section with nearly constant width and length, and a developing section controlled by the downstream bedload transport range. Increasing exit velocities enlarges pit width but shortens the developing section, whereas increasing translation speeds reduces local peak shear while extending the downstream transport range. An empirical regression model is proposed to predict the stable-section pit width, and a hyperbolic function is used to estimate the maximum scour depth and pit width at the scour point. These findings clarify sediment transport behavior under translating jets and provide predictive tools for engineering applications.
{"title":"Numerical investigation of scour on a sand bed induced by a moving vertical circular jet","authors":"Jiaqi Chen, Yao Jiang, Mengcheng Wang","doi":"10.1016/j.apor.2026.104986","DOIUrl":"10.1016/j.apor.2026.104986","url":null,"abstract":"<div><div>This study employs three-dimensional numerical simulations to investigate scour development on a sand bed induced by a translating vertical circular jet. Simulations were performed for jet exit velocities from 2 to 4 m/s and nozzle translation speeds from 0.05 to 0.2 m/s. The results show that nozzle translation rapidly terminates local erosion at previous impingement locations, while the induced horizontal momentum enhances downstream bedload mobility and allows limited suspended sediment transport. Sediment transport evolves through four stages, and the scour geometry transitions from an initially circular cavity to a ribbon-like depression with a spoon-shaped transport zone. The scour pit exhibits three characteristic sections, including an initial section that grows rapidly with increasing exit velocities, a stable section with nearly constant width and length, and a developing section controlled by the downstream bedload transport range. Increasing exit velocities enlarges pit width but shortens the developing section, whereas increasing translation speeds reduces local peak shear while extending the downstream transport range. An empirical regression model is proposed to predict the stable-section pit width, and a hyperbolic function is used to estimate the maximum scour depth and pit width at the scour point. These findings clarify sediment transport behavior under translating jets and provide predictive tools for engineering applications.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"168 ","pages":"Article 104986"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403057","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}
Pub Date : 2026-03-01Epub Date: 2026-02-05DOI: 10.1016/j.apor.2026.104957
Otto Neshamar , Alan J.S. Cuthbertson , Øyvind A. Thiem , Peter A. Davies
Laboratory experiments were conducted to investigate the transient release of graded particle mixtures into deep receiving waters through submerged vertical pipes with varying diameters and lengths. The experiments were scaled through geometric and dynamic similarity considerations to model the dumping of waste rock fragment masses into deep coastal waterbodies via enclosed vertical fall-pipes. The model rock fragment mixture was generated from colour-coded particle size classes, with their in-pipe vertical transport and release from the pipe exit measured from time-synchronised camera recordings. Quantitative image analysis methods were developed to determine the bulk and fractional particle velocities and concentrations at different pipe elevations and immediately below the pipe exit. For larger mass inputs, induced in-pipe fluid motions and particle mixing were strongly three-dimensional, characterised by upward and downward velocity fluctuations associated with oscillation and drawdown of the enclosed water surface. Equations of motion were developed to describe this transient free-surface behaviour within the pipe. Increased pipe confinement of the mass input was shown to hinder sedimentation from the fall-pipe, whilst promoting in-pipe segregation of the particle size classes released from the pipe exit. Finally, a series of sequential mass release experiments was conducted to investigate the quantity and fate of residual fines remaining in the fall-pipes after each mass input. These fines were ejected from the pipe exit as a puff or puffs before being re-entrained into the subsequent coarser particle stream. The implications of these scaled experimental measurements for optimising waste rock fragment mass disposal through vertical fall-pipes are discussed.
{"title":"Laboratory investigation of polydisperse rock releases into deep receiving waters through vertical, enclosed fall-pipes","authors":"Otto Neshamar , Alan J.S. Cuthbertson , Øyvind A. Thiem , Peter A. Davies","doi":"10.1016/j.apor.2026.104957","DOIUrl":"10.1016/j.apor.2026.104957","url":null,"abstract":"<div><div>Laboratory experiments were conducted to investigate the transient release of graded particle mixtures into deep receiving waters through submerged vertical pipes with varying diameters and lengths. The experiments were scaled through geometric and dynamic similarity considerations to model the dumping of waste rock fragment masses into deep coastal waterbodies via enclosed vertical fall-pipes. The model rock fragment mixture was generated from colour-coded particle size classes, with their in-pipe vertical transport and release from the pipe exit measured from time-synchronised camera recordings. Quantitative image analysis methods were developed to determine the bulk and fractional particle velocities and concentrations at different pipe elevations and immediately below the pipe exit. For larger mass inputs, induced in-pipe fluid motions and particle mixing were strongly three-dimensional, characterised by upward and downward velocity fluctuations associated with oscillation and drawdown of the enclosed water surface. Equations of motion were developed to describe this transient free-surface behaviour within the pipe. Increased pipe confinement of the mass input was shown to hinder sedimentation from the fall-pipe, whilst promoting in-pipe segregation of the particle size classes released from the pipe exit. Finally, a series of sequential mass release experiments was conducted to investigate the quantity and fate of residual fines remaining in the fall-pipes after each mass input. These fines were ejected from the pipe exit as a puff or puffs before being re-entrained into the subsequent coarser particle stream. The implications of these scaled experimental measurements for optimising waste rock fragment mass disposal through vertical fall-pipes are discussed.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"168 ","pages":"Article 104957"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122725","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}
Pub Date : 2026-03-01Epub Date: 2026-02-07DOI: 10.1016/j.apor.2026.104971
Xiu Zhu , Dangya Yang , Yan Qian , Hao Zhang , Bo Yin , Kefeng Deng , Jie Nie , Ning Song , Jiajing Wu , Qi Wen
Ocean waves exhibit significant multi-scale characteristics due to nonlinear interactions among multiple physical factors, including long-period global swells and short-period local wind–waves. The core challenge in accurately predicting significant wave height (SWH) lies in simultaneously capturing the spatio-temporal evolution of both global swell dynamics and local wind–wave dynamics. Existing single-architecture models based on Convolutional Neural Network (CNN) or Graph Convolutional Network (GCN) struggle to balance local features and global patterns due to limited receptive fields or insufficient temporal sensitivity, particularly under highly dynamic short-term sea conditions. To address these limitations, this paper proposes a novel Dual-Path Hybrid Convolutional Neural Network (DHCNN) that integrates a local spatial feature extraction module with a global graph structure modeling unit, overcoming the scale adaptability bottleneck of traditional models. Quantitative evaluations on the East Asia-Western Pacific Region (EAWPR) and Northwest Pacific Region (NPR) datasets demonstrate that our proposed DHCNN model achieves substantial improvements over state-of-the-art baselines. Compared to the strongest CNN-based baseline (MA-ConvLSTM), DHCNN reduces the 24-hour root mean square error (RMSE) by 5.68% on the EAWPR dataset and by 21.31% on the NPR dataset, while yielding consistent Pearson correlation coefficient (PCC) improvements of 0.58% on the EAWPR dataset. Relative to the best-performing GCN-based baseline (STGCN), DHCNN further decreases the 24-hour RMSE by 6.67% and 21.95% on the EAWPR and NPR datasets, respectively, while maintaining high fidelity in both global contours and local details. Typhoon case studies confirm DHCNN’s capability to accurately characterize intense wave phenomena under extreme conditions. The results indicate that DHCNN’s multi-scale feature fusion mechanism significantly enhances SWH prediction accuracy and robustness in complex marine environments, providing critical technical support for offshore engineering safety.
{"title":"Dual-path modeling of global swell and local wave features for short-term significant wave height spatio-temporal forecasting using hybrid convolutional networks","authors":"Xiu Zhu , Dangya Yang , Yan Qian , Hao Zhang , Bo Yin , Kefeng Deng , Jie Nie , Ning Song , Jiajing Wu , Qi Wen","doi":"10.1016/j.apor.2026.104971","DOIUrl":"10.1016/j.apor.2026.104971","url":null,"abstract":"<div><div>Ocean waves exhibit significant multi-scale characteristics due to nonlinear interactions among multiple physical factors, including long-period global swells and short-period local wind–waves. The core challenge in accurately predicting significant wave height (SWH) lies in simultaneously capturing the spatio-temporal evolution of both global swell dynamics and local wind–wave dynamics. Existing single-architecture models based on Convolutional Neural Network (CNN) or Graph Convolutional Network (GCN) struggle to balance local features and global patterns due to limited receptive fields or insufficient temporal sensitivity, particularly under highly dynamic short-term sea conditions. To address these limitations, this paper proposes a novel Dual-Path Hybrid Convolutional Neural Network (DHCNN) that integrates a local spatial feature extraction module with a global graph structure modeling unit, overcoming the scale adaptability bottleneck of traditional models. Quantitative evaluations on the East Asia-Western Pacific Region (EAWPR) and Northwest Pacific Region (NPR) datasets demonstrate that our proposed DHCNN model achieves substantial improvements over state-of-the-art baselines. Compared to the strongest CNN-based baseline (MA-ConvLSTM), DHCNN reduces the 24-hour root mean square error (RMSE) by 5.68% on the EAWPR dataset and by 21.31% on the NPR dataset, while yielding consistent Pearson correlation coefficient (PCC) improvements of 0.58% on the EAWPR dataset. Relative to the best-performing GCN-based baseline (STGCN), DHCNN further decreases the 24-hour RMSE by 6.67% and 21.95% on the EAWPR and NPR datasets, respectively, while maintaining high fidelity in both global contours and local details. Typhoon case studies confirm DHCNN’s capability to accurately characterize intense wave phenomena under extreme conditions. The results indicate that DHCNN’s multi-scale feature fusion mechanism significantly enhances SWH prediction accuracy and robustness in complex marine environments, providing critical technical support for offshore engineering safety.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"168 ","pages":"Article 104971"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186906","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}
Pub Date : 2026-03-01Epub Date: 2026-02-11DOI: 10.1016/j.apor.2026.104946
Song Li , Li-zhong Wang , Li-lin Wang , Yi Hong , Qi Li , Jia-wang Chen
To reduce the cost per installed kW, scaling up floating offshore wind turbines (FOWTs) is an inevitable trend. However, the heavy weight of tall towers restricts the growth of tower stiffness, making mainstream rigid tower designs difficult to achieve. In addition, larger structures mean larger loads, and the effects of scaling up on various wind turbine structures are not well understood. This paper aims to identify the effects of scaling up on the wind turbine tower, floater, and mooring system through a dynamic perspective by comparing the latest 22 MW wind turbine model with the 15 MW model. The comparison reveals that (a) the first fore-aft tower bending frequency of the 22 MW FOWT approaches 3P, and this mode also affects the mooring forces, and (b) the heave motion of the 22 MW turbine is excessive under extreme sea conditions. The analysis identifies two resonance phenomena: pitch motion enhances the tower frequency, causing resonance between the first fore-aft tower bending mode and the blade’s 3P frequency, and resonance between floater heave and wave loads in extreme sea conditions. Subsequently, adjustments are made to the mass distribution of the floater and the cross-sectional configuration of the floater pontoon based on the observed resonance mechanism. The new model is validated through simulation analysis of wind turbine behavior under extreme sea conditions. Compared to the original 22 MW model, the newly proposed model effectively avoids resonance frequencies. It has two additional capabilities: (a) increased pitch inertia about the center of gravity reduces the first fore-aft tower bending frequency, and (b) added mass and damping in the heave direction decrease the frequency and amplitude of heave motion.
{"title":"Structural dynamics and resonance mitigation in upscaled floating offshore wind turbines: From 15 MW to 22 MW","authors":"Song Li , Li-zhong Wang , Li-lin Wang , Yi Hong , Qi Li , Jia-wang Chen","doi":"10.1016/j.apor.2026.104946","DOIUrl":"10.1016/j.apor.2026.104946","url":null,"abstract":"<div><div>To reduce the cost per installed kW, scaling up floating offshore wind turbines (FOWTs) is an inevitable trend. However, the heavy weight of tall towers restricts the growth of tower stiffness, making mainstream rigid tower designs difficult to achieve. In addition, larger structures mean larger loads, and the effects of scaling up on various wind turbine structures are not well understood. This paper aims to identify the effects of scaling up on the wind turbine tower, floater, and mooring system through a dynamic perspective by comparing the latest 22 MW wind turbine model with the 15 MW model. The comparison reveals that (a) the first fore-aft tower bending frequency of the 22 MW FOWT approaches 3P, and this mode also affects the mooring forces, and (b) the heave motion of the 22 MW turbine is excessive under extreme sea conditions. The analysis identifies two resonance phenomena: pitch motion enhances the tower frequency, causing resonance between the first fore-aft tower bending mode and the blade’s 3P frequency, and resonance between floater heave and wave loads in extreme sea conditions. Subsequently, adjustments are made to the mass distribution of the floater and the cross-sectional configuration of the floater pontoon based on the observed resonance mechanism. The new model is validated through simulation analysis of wind turbine behavior under extreme sea conditions. Compared to the original 22 MW model, the newly proposed model effectively avoids resonance frequencies. It has two additional capabilities: (a) increased pitch inertia about the center of gravity reduces the first fore-aft tower bending frequency, and (b) added mass and damping in the heave direction decrease the frequency and amplitude of heave motion.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"168 ","pages":"Article 104946"},"PeriodicalIF":4.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186900","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}
Pub Date : 2026-02-01Epub Date: 2026-01-28DOI: 10.1016/j.apor.2026.104945
Fulong Shi , Yu Tian , Cui Ma , Yingbin Zhang , Jianjian Xin , Xing Chang
During water entry, hull profiles of varying geometries induce pronounced air-cushion effects and slamming load oscillations, which may lead to structural failure or fatigue damage. This paper employed a self-developed CPU/GPU heterogeneous parallel numerical platform based on the Radial Basis Function Ghost Cell Method (RBFGCM) to investigate the slamming characteristics of symmetric and asymmetric curved wedges with different curvatures. The analysis concentrates on load variations, air cushion dynamics, and free-surface evolution. The results reveal that symmetric wedges with smaller curvature demonstrate smoother velocity decay, lower hydrodynamic resistance, and prolonged pressure oscillations with a uniform distribution. Conversely, larger radius of curvature wedges exhibited 133.3% higher instantaneous pressure peaks and accelerated velocity dissipation, accompanied by intensified free surface disturbances and premature jet separation. Increasing the deadrise angle from 25° to 35° reduces the peak slamming pressure by 39%. For asymmetric impacts, larger radius of curvature decreased the lateral load amplitude by 58% with mitigated oscillations. The C1 configuration displays distinctive positive-negative phase transitions at a 15° inclination, whereas the C5 profile maintains 32% lower lateral load fluctuations. The vertical force coefficient analysis reveals localized high-pressure zones for specific inclination-deadrise pairs: 25° deadrise at 25° inclination and 35° deadrise at 30° inclination. These findings provide critical insights for optimizing hull geometry in high-speed vessel design, enabling balanced load mitigation and hydrodynamic stability through strategic curvature parameter selection.
{"title":"Numerical prediction of slamming loads on hull profile structures with varying curvatures during water entry","authors":"Fulong Shi , Yu Tian , Cui Ma , Yingbin Zhang , Jianjian Xin , Xing Chang","doi":"10.1016/j.apor.2026.104945","DOIUrl":"10.1016/j.apor.2026.104945","url":null,"abstract":"<div><div>During water entry, hull profiles of varying geometries induce pronounced air-cushion effects and slamming load oscillations, which may lead to structural failure or fatigue damage. This paper employed a self-developed CPU/GPU heterogeneous parallel numerical platform based on the Radial Basis Function Ghost Cell Method (RBFGCM) to investigate the slamming characteristics of symmetric and asymmetric curved wedges with different curvatures. The analysis concentrates on load variations, air cushion dynamics, and free-surface evolution. The results reveal that symmetric wedges with smaller curvature demonstrate smoother velocity decay, lower hydrodynamic resistance, and prolonged pressure oscillations with a uniform distribution. Conversely, larger radius of curvature wedges exhibited 133.3% higher instantaneous pressure peaks and accelerated velocity dissipation, accompanied by intensified free surface disturbances and premature jet separation. Increasing the deadrise angle from 25° to 35° reduces the peak slamming pressure by 39%. For asymmetric impacts, larger radius of curvature decreased the lateral load amplitude by 58% with mitigated oscillations. The C1 configuration displays distinctive positive-negative phase transitions at a 15° inclination, whereas the C5 profile maintains 32% lower lateral load fluctuations. The vertical force coefficient analysis reveals localized high-pressure zones for specific inclination-deadrise pairs: 25° deadrise at 25° inclination and 35° deadrise at 30° inclination. These findings provide critical insights for optimizing hull geometry in high-speed vessel design, enabling balanced load mitigation and hydrodynamic stability through strategic curvature parameter selection.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"167 ","pages":"Article 104945"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090413","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}
Pub Date : 2026-02-01Epub Date: 2026-01-29DOI: 10.1016/j.apor.2026.104949
Ashley N. Chong, Paul M. Koola, Sharath S. Girimaji
Wave energy conversion (WEC) systems have long promised a sustainable source of renewable energy. However, their progress remains constrained by persistently low conversion efficiencies and the absence of standardized practices for comparing system performance across studies and devices. Energy auditing is a critical element of experimental methodology for establishing confidence and credibility in laboratory investigations and the subsequent design of wave-energy systems. Its implementation is challenging: the energy input (decomposition of incident and reflected wave power), the useful output (device absorption), and especially losses (leakage, pneumatic, viscous, and radiative) are difficult to quantify. Recognizing these challenges, this paper presents an energy-balance framework for oscillating water column (OWC) laboratory studies and reports preliminary experimental results. The measurements integrate a four-probe incident/reflected decomposition and synchronized chamber-power measurements with a baseline loss model to evaluate overall energy closure. Two analysis windows—pre-rebound (Region 1) and post-rebound (Region 2)—are used to examine the influence of wave re-encounters and finite-flume effects. Application to initial flume measurements reveals a modest yet non-negligible range of unaccounted power and identifies conditions under which frequency-dependent losses may become significant. On the basis of these observations, the study offers lessons learned and best-practice recommendations for probe placement, calibration and leakage checks, and transparent reporting of residuals. The proposed framework establishes a reproducible foundation for OWC experimentation, enabling systematic optimization and informing design improvements.
{"title":"A framework for energy-balance audits in laboratory OWC experiments","authors":"Ashley N. Chong, Paul M. Koola, Sharath S. Girimaji","doi":"10.1016/j.apor.2026.104949","DOIUrl":"10.1016/j.apor.2026.104949","url":null,"abstract":"<div><div>Wave energy conversion (WEC) systems have long promised a sustainable source of renewable energy. However, their progress remains constrained by persistently low conversion efficiencies and the absence of standardized practices for comparing system performance across studies and devices. Energy auditing is a critical element of experimental methodology for establishing confidence and credibility in laboratory investigations and the subsequent design of wave-energy systems. Its implementation is challenging: the energy input (decomposition of incident and reflected wave power), the useful output (device absorption), and especially losses (leakage, pneumatic, viscous, and radiative) are difficult to quantify. Recognizing these challenges, this paper presents an energy-balance framework for oscillating water column (OWC) laboratory studies and reports preliminary experimental results. The measurements integrate a four-probe incident/reflected decomposition and synchronized chamber-power measurements with a baseline loss model to evaluate overall energy closure. Two analysis windows—pre-rebound (Region 1) and post-rebound (Region 2)—are used to examine the influence of wave re-encounters and finite-flume effects. Application to initial flume measurements reveals a modest yet non-negligible range of unaccounted power and identifies conditions under which frequency-dependent losses may become significant. On the basis of these observations, the study offers lessons learned and best-practice recommendations for probe placement, calibration and leakage checks, and transparent reporting of residuals. The proposed framework establishes a reproducible foundation for OWC experimentation, enabling systematic optimization and informing design improvements.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"167 ","pages":"Article 104949"},"PeriodicalIF":4.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090415","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号