Ocean Engineering最新文献

{"title":"Vibration reduction of floating offshore wind turbine with nonlinear vibration absorber: Concept, numerical analysis and experimental tests","authors":"Hang Zhang ,&nbsp;Binrong Wen ,&nbsp;Xinliang Tian ,&nbsp;Xiaofan Li ,&nbsp;Xin Li ,&nbsp;Zhike Peng","doi":"10.1016/j.oceaneng.2025.121196","DOIUrl":"10.1016/j.oceaneng.2025.121196","url":null,"abstract":"<div><div>Floating offshore wind turbines (FOWTs), as emerging energy systems, are subjected to environmental loads from winds, waves, and currents throughout their operational lifespan. Numerous strategies have been proposed to mitigate FOWT vibrations, aiming to enhance structural safety and stability. However, conventional linear vibration absorbers are often limited in their effectiveness, as they are typically designed for specific frequencies. In this paper, a nonlinear vibration absorber (NVA) is introduced, which achieves nonlinear stiffness through the orthogonal arrangement of springs. A numerical model of the FOWT equipped with the NVA is developed, and a semi-analytic technique is employed to reveal the targeted energy transfer (TET) and resonance capture cascading (RCC) phenomena occurring during the vibration reduction process, with the goal of achieving efficient mitigation performance and multi-modal vibration absorption. Additionally, an integrated FOWT-NVA wave basin test system is established, and extensive experiments are conducted under various offshore environments and absorber operating conditions. The results demonstrate that the NVA exhibits excellent vibration control performance and frequency robustness. Compared to conventional linear absorbers (such as tuned mass dampers, TMDs), the NVA significantly improves vibration reduction in both tower top responses and tower-base loads. This study validates the effectiveness of the NVA and provides a foundation for future experimental techniques and advanced controllers for FOWTs.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"331 ","pages":"Article 121196"},"PeriodicalIF":4.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854637","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":"Lateral and vertical bearing characteristics of monopile and pile groups under scour condition: model test and calculation method","authors":"Yutao Peng ,&nbsp;Haoran OuYang ,&nbsp;Wei Qin ,&nbsp;Weiming Gong ,&nbsp;Guoliang Dai","doi":"10.1016/j.oceaneng.2025.121232","DOIUrl":"10.1016/j.oceaneng.2025.121232","url":null,"abstract":"<div><div>With the rapid development of offshore wind power and cross‒sea bridges, the negative impact of scour on the bearing capacity of pile foundations has garnered increasing attention. While pile groups are more widely applied in engineering practice, most studies on scour effects have primarily focused on single piles. This study presents a series of laboratory static load tests, both vertical and lateral, on the monopile, five‒pile, and nine‒pile foundations. The study thoroughly investigates the variations in bearing capacity, pile moment distribution, group pile efficiency factor, and load‒sharing ratios under different scour conditions. The findings indicate that, similar to single piles, the lateral bearing capacity of pile groups decreases as the scour depth increases. Both lateral and vertical group pile efficiency factors increase with the intensification of scour, whereas under identical conditions, they exhibit a decrease as the number of piles increases, with the rate of reduction progressively diminishing. Among the pile group configurations, the corner piles in the front row are the most affected by scour depth and lateral loading. Therefore, the study suggests that effective reinforcement measures should be incorporated into the design of front corner piles. Additionally, this study establishes modified <em>p‒y</em> curves that account for the impact of scour dimensions based on the strain wedge model. Parametric analysis of scour depth, width, and slope angle further elucidates the influence of scour on the bearing characteristics of both single piles and pile groups, providing crucial insights for engineering design.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"331 ","pages":"Article 121232"},"PeriodicalIF":4.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854642","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":"Robust sliding mode model predictive control and thrust allocation methods for autonomous berthing of water-jet propulsion unmanned surface vehicles","authors":"Jun-Tong Qi ,&nbsp;Wen-Chong Liang ,&nbsp;Wen-Bo Xie ,&nbsp;Yan Peng","doi":"10.1016/j.oceaneng.2025.121280","DOIUrl":"10.1016/j.oceaneng.2025.121280","url":null,"abstract":"<div><div>For the problem of berthing control of a water-jet unmanned surface vessel (USV), a sliding mode model predictive controller with thrusts allocation (TA) method is proposed in this paper. At first, considering the TA may not perfectly match the control commands, thus the errors between controller and TA are involved in the system model as uncertainties. Then a sliding mode control (SMC) approach is designed to guarantee the system stability when control input uncertainties exist. And a Lyapunov-based model predictive control (LMPC) is proposed to inherit the robust performance of the given SMC and incorporate certain control input constraints. For the TA module, actual physical constraints of the actuators are comprehensively considered, then the TA optimization problem is solved by interior point methods to close the system loop. Simulation results demonstrate the effectiveness of the proposed method for the water-jet propulsion USV to accomplish the autonomous berthing task.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"331 ","pages":"Article 121280"},"PeriodicalIF":4.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859672","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":"Task-oriented adaptive dive tracking control for autonomous underwater vehicle with system uncertainties and disturbances","authors":"Yuchen Lu ,&nbsp;Liang Cheng ,&nbsp;Jianbo Wu ,&nbsp;Xinwei Lu ,&nbsp;Jiangxiong Li ,&nbsp;Yinglin Ke","doi":"10.1016/j.oceaneng.2025.121243","DOIUrl":"10.1016/j.oceaneng.2025.121243","url":null,"abstract":"<div><div>Achieving high-precision motion control for Autonomous Underwater Vehicles (AUVs) in the vertical plane requires both effective path planning and robust trajectory tracking. Traditional approaches treat these two modules separately, which can lead to infeasible tracking trajectories and suboptimal control performance. To address these limitations, this paper proposes a task-oriented adaptive dive tracking control (ToADTC) framework, which integrates controller constraint into the planning process while simultaneously refining the desired trajectory during trajectory tracking. By defining the optimization problem from the task-level perspective, the desired trajectory is no longer prescribed in advance but can be optimized together with the control input signals within the tracking loop. Moreover, a contracted robustness constraint is incorporated into the optimizing loop, ensuring both the robust control performance and feasibility of the optimization problem. Meanwhile, the Lyapunov method is employed to guarantee the closed-loop stability of the AUV system rigorously. The proposed method is validated through extensive simulations, comparing its performance with conventional control approaches. The results demonstrate that ToADTC method improves robustness against disturbances, and enhances overall control performance in complex underwater environments.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"331 ","pages":"Article 121243"},"PeriodicalIF":4.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859673","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":"Mitigation of vibrations and its optimization in a large floating wind turbine across different typhoon stages","authors":"Lei Ren ,&nbsp;Hao Wang ,&nbsp;Xin Cai ,&nbsp;Jiaojie Xie ,&nbsp;Zhitong Lv ,&nbsp;Yazhou Wang ,&nbsp;Bofeng Xu","doi":"10.1016/j.oceaneng.2025.121287","DOIUrl":"10.1016/j.oceaneng.2025.121287","url":null,"abstract":"<div><div>Typhoon disasters challenge the development of offshore wind power in typhoon-prone areas, particularly in Chinese water, as existing standards inadequately address turbine requirements under extreme conditions, leading to vibration issues that limit deep-water deployment. This study develops a fully coupled aero-hydro-servo-elastic-mooring model for the NREL 15 MW semi-submersible floating wind turbine with Tuned Mass Damper (TMD) control, using Typhoon Rammasun as a representative case to assess the impact of different phases on 3D pulsating wind field simulations. The dynamic response of the NREL 15 MW semi-submersible floating wind turbine under various TMD controls and stages of Typhoon Rammasun was studied. A TMD parameter optimization framework using OpenFAST, MATLAB, and NSGA-II algorithm was proposed. Results show that Pitch-TMD reduces pitch response by 9.5 % and fore-aft bending moment by 4.7 % under eyewall conditions (wind speeds &gt;70 m/s). Optimized Pitch-TMD parameters further reduced pitch and roll by 6 % and 11.8 %, and bending moment by 2.1 %. Notably, the turbine in shutdown mode in the outer vortex region exhibited smaller responses than during normal operation within the typhoon eye. Additionally, Extreme typhoon mooring line design should consider wind-wave alignment impacts.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"330 ","pages":"Article 121287"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852101","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":"Adaptive prescribed performance control for dynamic positioning SSPs with dynamic actuators’ faults","authors":"Yongsheng Dou ,&nbsp;Chenfeng Huang ,&nbsp;Xianku Zhang ,&nbsp;Dawei Gao ,&nbsp;Meirong Wei","doi":"10.1016/j.oceaneng.2025.121179","DOIUrl":"10.1016/j.oceaneng.2025.121179","url":null,"abstract":"<div><div>This paper presents a control scheme for the dynamic positioning (DP) semi-submersible platform (SSP) with dynamic actuators’ faults. In this algorithm, robust damping technique is employed to adaptively compensate for actuator gain uncertainties and system model uncertainties. Furthermore, by incorporating a tuning parameter with contractibility into a <span><math><mrow><mi>l</mi><mi>n</mi></mrow></math></span>-type performance function, a simplified prescribed performance control (PPC) strategy based on barrier error transformation is derived. The dynamic error is ensured to converge from the initial state to the predefined region by means of shifting function. Additionally, a fault correcting gain is used to provide online compensation for the effects of dynamic actuators’ faults, which is incorporated into the adaptive controller. Under the effect of the designed controller, all signals within the entire closed-loop system are proved to semi-globally ultimately uniformly bounded (SGUUB) stability by the Lyapunov stability theory. Finally, the closed-loop performance simulations confirm the algorithm’s effectiveness in PPC and FTC, the comparison simulations confirm the algorithm’s superiority with the faster convergence speed, economic efficiency, and reduced computational burden.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"330 ","pages":"Article 121179"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852103","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 pitching splitter plate on the wake topology and drag reduction of two square cylinders in tandem arrangement","authors":"Prabir Sikdar ,&nbsp;Sunil Manohar Dash","doi":"10.1016/j.oceaneng.2025.121283","DOIUrl":"10.1016/j.oceaneng.2025.121283","url":null,"abstract":"<div><div>An active flow control mechanism using a hinged splitter plate is explored to modify wake topology and reduce drag of tandem square cylinders (TSCs) at pitch ratio of <em>G/D</em> = 6 and Reynolds Number <em>Re</em> = 100, where <em>G</em> represents the centre-to-centre spacing between cylinders of length <em>D</em>. The rigid plate is hinged at the midpoint of the upstream cylinder's rear face (HSPU). The governing parameters are pitching amplitudes (<span><math><mrow><msub><mi>θ</mi><mi>m</mi></msub></mrow></math></span> = 10°–20°), non-dimensional frequencies (<span><math><mrow><msub><mrow><mi>S</mi><mi>t</mi></mrow><mi>f</mi></msub><mo>=</mo><msub><mi>f</mi><mi>f</mi></msub><mi>A</mi><mo>/</mo><mi>U</mi></mrow></math></span> = 0.1 − 0.4), and length <span><math><mrow><mo>(</mo><msub><mi>L</mi><mi>f</mi></msub><mo>/</mo><mi>D</mi></mrow></math></span> = 0–1) of the plate, which significantly affects wake structures, nature of vortex-interactions, pressure distribution, aerodynamic forces, power consumption, and effectiveness of drag reduction. Here, <span><math><mrow><msub><mi>f</mi><mi>f</mi></msub></mrow></math></span> and <em>A</em> are the pitching frequency and total excursion of the tail end of the plate, respectively. The free-stream velocity is <em>U</em>. Four distinct flow regimes are identified for the TSC-HSPU setup. Type – I involves von Karman vortex shedding, where the upstream cylinder vortex (UCV) dominates over the plate vortex (PV) in the cylinder gap region. For Type – II, bigger and stronger PVs induce a chain-like vortex pattern. In Type – III, PVs become sufficiently strong to inhibit UCVs shedding. In Type − IV, the strongest PVs interact with UCVs and generate a new vortex that dominates the cylinder gap region. Notably, Type − II and Type − III regimes yield lower drag. In comparison to TSC, the highest drag reduction of the TSC-HSPU setup is 47 %, obtained at <span><math><mrow><msub><mi>L</mi><mi>f</mi></msub><mo>/</mo><mi>D</mi></mrow></math></span> = 1.00, <span><math><mrow><msub><mrow><mi>S</mi><mi>t</mi></mrow><mi>f</mi></msub></mrow></math></span> = 0.20, and <span><math><mrow><msub><mi>θ</mi><mi>m</mi></msub></mrow></math></span> = 10°.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"330 ","pages":"Article 121283"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852220","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":"Aeroelastic investigations of composite blade on floating offshore wind Turbine: Insights into stress responses on multi-hierarchy blade structures","authors":"ZhongSheng Deng ,&nbsp;Qing Xiao ,&nbsp;Liu Yang ,&nbsp;YuanChuan Liu ,&nbsp;Enhao Wang","doi":"10.1016/j.oceaneng.2025.121305","DOIUrl":"10.1016/j.oceaneng.2025.121305","url":null,"abstract":"<div><div>To improve the blades aeroelastic performance on floating offshore wind turbines, it is essential to analyse the stress conditions and distributions on composite blades. This paper serves as a continuation of the previous work, we examined the impacts of FOWT platform surge periods and amplitudes to the composite blade aeroelastics, with considerations of turbulent effects when solving for the aerodynamic loads. The result shows that a shorter surge period and larger surge amplitude can lead to significant stress amplifications. The stress concentrations are predominantly observed on the blade substructure shear webs, underscoring the need for local stress inspections. A linear relationship between surge amplitude and local max. stress magnitude is identified, which is helpful for a quick preliminary blade design. The findings contribute to the development of more robust and efficient offshore wind energy systems, providing detailed aeroelastic insights for the blade optimizations in the future works.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"330 ","pages":"Article 121305"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854449","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":"Hybrid finite element and machine learning approach for estimating lateral capacity of partially rock-socketed monopiles","authors":"Shamsher Sadiq ,&nbsp;Myoung-Soo Won ,&nbsp;Hyeon Jung Kim ,&nbsp;Chengyu Hong","doi":"10.1016/j.oceaneng.2025.121286","DOIUrl":"10.1016/j.oceaneng.2025.121286","url":null,"abstract":"<div><div>This study combines finite element (FE) simulations and soft computing techniques to predict lateral capacity (H) of partially rock-socketed monopiles. A three-dimensional (3D) nonlinear FE model of monopile-soil interaction was developed and validated against centrifuge experimental data. The FE simulations were used to generate 240 monopile configurations, where the monopile length (L), diameter (D), lateral loading eccentricity (e) and sand relative density (D_r) were varied while keeping the rock-socketed length equal to the monopile diameter. We applied three machine learning algorithms to this database to establish predictive models: Adaptive Boosting (AdaBoost), Random Forest (RF), and Extreme Gradient Boosting (XGBoost), for which the hyper-parameters were optimized and evaluated by 10-fold cross-validation. The XGBoost demonstrated highest prediction accuracy (R²:0.986, RMSE: 5.43), outperforming RF and AdaBoost. Shapley Additive Explanations (SHAP) showed the relative importance of input features, ranking them as D &gt; e &gt; L &gt; D_r. A parametric study further verified that the model outputs capture physical behavior and align with theoretical understanding by varying each input while keeping others constant at their mean values. A flexible prediction framework was developed using MAPE and conservatism level as guiding metrics. To unable real-world use, a user-friendly GUI was implemented based on XGBoost model, facilitating efficient prediction without requiring extensive FE computations.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"330 ","pages":"Article 121286"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and numerical investigation of the interaction between extreme waves and composite large-diameter cylindrical breakwater","authors":"Tianyu Zheng ,&nbsp;Kai Yin ,&nbsp;Wei Lin ,&nbsp;Sudong Xu","doi":"10.1016/j.oceaneng.2025.121282","DOIUrl":"10.1016/j.oceaneng.2025.121282","url":null,"abstract":"<div><div>The widespread application of large-diameter cylinders in offshore cofferdams highlights their potential as breakwater structures. Understanding the wave attenuation characteristics of large-diameter cylindrical breakwaters is fundamental to further applications. Existing studies are mainly focusing on small-diameter cylindrical breakwaters and non-extreme wave conditions. Hence, a novel large-diameter cylindrical breakwater (CLCB) is proposed by integrating the side plate, crown wall and apron into large-diameter cylinders. A set of wave flume experiments on the hydraulic performance of CLCB under extreme wave conditions were conducted. The reliability of the developed numerical model is revealed based on a series of model validations. A comprehensive analysis is conducted to investigate the effects of different structure parameters on wave attenuation performance. The simulation results indicate that increasing the height of the side plate and crown wall could significantly decrease the wave transmission coefficient, while variations in apron height have a limited influence. Within the parameters utilized in this investigation, CLCB demonstrates superior wave attenuation performance under extreme wave conditions, better than that under non-extreme wave environments. The results from this study optimize the design of large-diameter cylindrical breakwaters and generate new insights into the interaction between large-diameter cylindrical breakwaters and extreme waves.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"330 ","pages":"Article 121282"},"PeriodicalIF":4.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852102","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}