Article
Engineering, Marine
Diane Scicluna, Claire De Marco Muscat-Fenech, Tonio Sant, Giuliano Vernengo, Tahsin Tezdogan
Summary: This paper provides a detailed analysis of the hydrostatic stability characteristics of a novel floating wind turbine concept. The study focuses on offshore wind resources with water depths greater than 100 m and validates the theoretical calculations using SESAM. The results show that the floating structure exhibits hydrostatic stability characteristics that comply with industry standards.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Marine
Gayathry Rajiv, Mohit Verma, A. Subbulakshmi
Summary: This paper discusses the complexity of the dynamics of floating offshore wind turbines and proposes the use of Gaussian process metamodels for representing the hydrodynamics and structural dynamics of the floating platform. Three different Gaussian process metamodels are considered and compared in terms of evaluation indices, convergence, residuals and computational efficiency. The results show that all three Gaussian process metamodels are effective in emulating the response of the platform and can be used in situations where simple and computationally inexpensive models are required.
Article
Green & Sustainable Science & Technology
Jianbing Chen, Zenghui Liu, Yupeng Song, Yongbo Peng, Jie Li
Summary: This paper presents a scaled model experiment of a spar-type floating offshore wind turbine (FOWT) and proposes an optimal arrangement scheme for anemometers deployment to improve wind field measurement efficiency. Load case tests are conducted to capture the rigid-body motion of the FOWT model, tower deformation, and mooring tension. The experiment reveals the influence of the rotor on yaw and the dominance of aerodynamic loads and hydrodynamic loads on the trend and amplitude of structural rigid-body motion, respectively. The resonant response caused by doubling frequency coupling effects in the flexible tower is also significant. The experiment serves as a benchmark for the validation of numerical simulation tools for FOWTs.
Article
Thermodynamics
Yu Zhou, Dezhi Ning, Lifen Chen, Robert Mayon, Chongwei Zhang
Summary: This paper evaluates the hydrodynamic performance of a multi-functional floating foundation that integrates an Oscillating Water Column (OWC) Wave Energy Converter (WEC) with a Floating Offshore Wind Turbine (FOWT). The tests demonstrate that introducing the OWC device enhances the stability of the FOWT in heave motion.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Engineering, Civil
Jonas P. P. Falcao, Jose L. V. de Brito, Suzana M. M. Avila, Marcus V. G. de Morais
Summary: This paper describes a method for controlling the vibrations of floating offshore wind turbines (FOWTs) using a proposed tuned mass damper with an inverted pendulum (TMD-IP). The results show that the TMD-IP can effectively reduce tower rotation and barge translation, achieving reductions of approximately 95% and 70% respectively under harmonic excitation and random wind loading.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Green & Sustainable Science & Technology
Daniel Micallef, Abdolrahim Rezaeiha
Summary: Over the past decade, there has been a steady increase in scientific articles on rotor aerodynamics of offshore wind turbines, highlighting the critical role of aerodynamics in overcoming specific barriers in multi-physics systems. Current trends in research focus on the interaction between aerodynamics and other fields, such as platform hydrodynamics and control, with common approaches being coupled or uncoupled studies. The literature mainly addresses isolated floating turbines, while studies on interactions between floating turbines are limited.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Engineering, Marine
S. Muggiasca, F. Taruffi, A. Fontanella, S. Di Carlo, H. Giberti, A. Facchinetti, M. Belloli
Summary: Multi-purpose offshore structures are complex systems that require consideration of various requirements simultaneously. Experimental tests on scaled models are useful for verifying structural behavior and validating numerical models, with the scale playing a key role in obtaining reliable results. This paper focuses on the design of a wind turbine model for a large-scale model of a Multi-purpose offshore Platform developed within the EU project H2020 Blue Growth Farm, aiming to develop an offshore farm integrating wave energy converters, a wind turbine, and aquaculture.
Article
Green & Sustainable Science & Technology
Yang Zhou, Qing Xiao, Yuanchuan Liu, Atilla Incecik, Christophe Peyrard, Decheng Wan, Guang Pan, Sunwei Li
Summary: The present study investigates the effect of turbulent wind and shear wind on the structure of a floating offshore wind turbine using a high-fidelity computational fluid dynamics method. The study demonstrates that turbulent wind causes fluctuations in rotor thrust and power outputs, and results in faster wake diffusion compared to time-independent inflow wind. Wind shear exacerbates the decrease in local minimum thrust/power. However, under the current wind inflow conditions, neither turbulent wind nor wind shear significantly affect the inline surge force, dynamic motion, and mooring tension of the floater.
Article
Engineering, Marine
Fanxu Zeng, Ningchuan Zhang, Guoxing Huang, Qian Gu, Meng He
Summary: This study conducted experiments to investigate the dynamic response of a floating offshore wind turbine (FOWT) under freak wave actions. Various freak wave profiles were generated in a wave basin and their effects on the FOWT were measured and analyzed. The findings of this study provide insights for the design of FOWT and benchmarks for validating numerical models.
Review
Green & Sustainable Science & Technology
Emma C. Edwards, Anna Holcombe, Scott Brown, Edward Ransley, Martyn Hann, Deborah Greaves
Summary: Using floating platforms is crucial for many countries to achieve their Net-Zero targets due to the limitations of fixed offshore wind turbines. However, the development of floating offshore wind turbine platforms is still in its early stages with a variety of designs. This paper reviews the current state-of-the-art designs and discusses the goals, features, and cost of energy values associated with floating offshore wind. The evolution of platform designs and overall trends are also examined.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2023)
Article
Engineering, Marine
Xifeng Gao, Xiaoyong Liu, Xutian Xue, Nian-Zhong Chen
Summary: This paper summarized a study on the applicability of a fracture mechanics-based approach for calculating the fatigue lives of mooring lines of a floating offshore wind turbine. The results showed that the approach provides a reasonable estimate of fatigue lives and is sensitive to stress concentration factor and initial crack size. Parametric studies and comparative analysis of different mooring designs were conducted to further investigate the effects and applicability of each design.
Article
Energy & Fuels
Gabriela Grasu, Pengfei Liu
Summary: Floating Offshore Wind has the potential to provide an effective solution for the increasing energy demand of coastal communities around the world if the specific risks associated with this novel technology are understood and evaluated.
Article
Engineering, Marine
Yiming Zhou, Yajun Ren, Wei Shi, Xin Li
Summary: Tension leg platform (TLP) is a cost-effective and high-performance support structure for floating offshore wind turbine (FOWT). This paper describes a newly proposed Braceless-TLP FOWT designed for a moderate water depth, and evaluates its performance under different weather conditions through numerical simulations.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Review
Engineering, Marine
Decao Yin, Elizabeth Passano, Fengjian Jiang, Halvor Lie, Jie Wu, Naiquan Ye, Svein Saevik, Bernt J. Leira
Summary: This study conducted a state-of-the-art review on influential VIM research, focusing on engineering practice, model tests, numerical calculation, and field measurement. Engineering gaps and potential research topics were identified for future work.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Thermodynamics
Hyebin Lee, Sunny Kumar Poguluri, Yoon Hyeok Bae
Summary: Vertical axis wind turbines (VAWT) have a lower center of mass due to the placement of mechanical systems at the bottom of the tower, resulting in more stable motions in offshore environments. However, torque effects lead to continuous loading of the tower, constant platform motions, and increased mooring tension. A contra-rotating VAWT is adopted to mitigate these effects by counterbalancing the torque produced by the two rotors.
Article
Engineering, Marine
Jian Zhang, Xiaobin Liu, Ming Zhan, Fang Wang, Xilu Zhao
Summary: This study examined the hydroforming and buckling of toroids with polyhedral sections and found that the hydroformed toroid can be employed in underwater vehicles. The results indicate that Jordan's equation can provide a conservative prediction of the ultimate allowable outer pressure of hydroformed toroids when the hydroforming pressure exceeds a certain threshold.
SHIPS AND OFFSHORE STRUCTURES
(2023)
Article
Acoustics
Lina Guo, Xiaosen Xu, Xinyan Zhang, Zhongyuan Chen, Ronghai He, Haile Ma
Summary: This study aimed to investigate the effect of ultrasound curing with various working modes and frequency combinations on the content of NaCl and tenderness of pork loins. The results showed that the NaCl content of samples cured by simultaneous ultra-sound with a frequency combination of 20, 40, and 60 kHz was higher than that of other ultrasound working modes. The physical qualities and microstructure of pork were also improved by simultaneous ultrasound treatment.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Oleg Gaidai, Yihan Xing, Xiaosen Xu
Summary: Two novel methods are proposed for spatiotemporal analysis of wind speeds and wave heights, contributing to global climate studies. A unique reliability approach is introduced for multi-dimensional structural and environmental dynamic system responses, and a novel deconvolution extrapolation technique is applied to a wide range of environmental and engineering applications. The study aims to evaluate the state-of-the-art approach that extracts essential information about the extreme responses from observed time histories.
SCIENTIFIC REPORTS
(2023)
Article
Multidisciplinary Sciences
Oleg Gaidai, Yihan Xing, Rajiv Balakrishna, Jingxiang Xu
Summary: This study proposes an innovative method for predicting extreme values in offshore engineering by considering environmental loads and structural reliability issues. The method differs from traditional approaches by not assuming any specific extrapolation function and relying on the intrinsic qualities of the data set. It has been demonstrated to be effective through the analysis of two wind speed data sets and comparison with the Naess-Gaidai method.
Article
Mechanics
Oleg Gaidai, Yubin Gu, Yihan Xing, Junlei Wang, Daniil Yurchenko
Summary: The paper investigates the stochastic dynamics of a two-degree-of-freedom system with a primary linear system connected to a nonlinear energy sink. The objective is to maximize the efficiency of energy transfer in the system. A surrogate optimization algorithm is proposed and applied to the stochastic framework. The results show clear trends in the coefficients of the nonlinear energy sink and demonstrate the impact of different cost functions on the optimal values of the nonlinear system's coefficients.
THEORETICAL AND APPLIED MECHANICS LETTERS
(2023)
Article
Green & Sustainable Science & Technology
Haibo Huo, Jiajie Chen, Ke Wang, Fang Wang, Guangzhe Jin, Fengxiang Chen
Summary: This paper deeply studies the mathematical mechanisms of cathode mass flow, anode mass flow, water content in PEM, and stack voltage of PEMFC. It further reports the dynamic output characteristics of PEMFC under the conditions of flooding and drying membrane and analyzes the influence of water content in PEM on the output performance of PEMFC. To effectively diagnose membrane drying and flooding faults, prolong their lifespan, and improve operation performance, this paper proposes the state assessment of water content in PEM based on GA-optimized BP neural network. Simulation results show that the GA-BP neural network has higher estimation accuracy compared to LS-SVM, laying a foundation for fault diagnosis, life extension, and control scheme design of PEMFC.
Article
Engineering, Marine
Oleg Gaidai, Jingxiang Xu, Vladimir Yakimov, Fang Wang
Summary: This research introduces a novel spatiotemporal reliability technique for high-dimensional structural systems. It enables the prediction of dynamic system failure risks based on in situ environmental load patterns. The authors apply this technique to 10-MW floating wind turbines and their dynamic responses, aiming to provide a state-of-the-art approach for the reliable study of offshore wind turbines.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Multidisciplinary Sciences
Jian Zhang, Oleg Gaidai, Hegang Ji, Yihan Xing
Summary: Due to climate change, the melting of Arctic glaciers has allowed trade ships to navigate in the summer. Even in the summer, there are still fragmented ice in the saltwater. The interaction between ships and ice is complex, and it is important to estimate high bow stresses accurately for proper vessel construction. This study utilizes a bivariate reliability approach to compute excessive bow forces encountered by oil tankers in the Arctic Ocean, taking into account ice thickness distribution.
Article
Multidisciplinary Sciences
Yihan Xing, Shuaishuai Wang, Anuraj Karuvathil, Rajiv Balakrishna, Oleg Gaidai
Summary: The global average size of offshore wind turbines has increased steadily from 1.5 MW to 6 MW from 2000 to 2020. Research has focused on larger 10-15 MW floating offshore wind turbines (FOWTs) due to their increased structural flexibility and complex responses. Accurate quantification of extreme dynamic responses is crucial for designing FOWT systems to withstand environmental conditions. The study explores the extreme responses of a 10 MW semi-submersible type FOWT under different operating conditions to guide future research on large FOWTs.
Article
Engineering, Multidisciplinary
Oleg Gaidai, Xiaosen Xu, Yihan Xing
Summary: A novel deconvolution method is proposed to accurately predict extreme hawser tensions during Floating Production Storage and Offloading (FPSO) operations. The predicted values obtained by the new approach are compared with those from the Naess-Gaidai method, and the results suggest that the deconvolution method provides a more robust and accurate forecast of excessive hawser stress. This method can be effectively used during vessel design to determine appropriate characteristics and reduce potential FPSO hawser stress.
RESULTS IN ENGINEERING
(2023)
Article
Engineering, Ocean
Jian Tan, Wei Tao, Antonio Jarquin Laguna, Henk Polinder, Yihan Xing, Sape Miedema
Summary: Wave-to-wire models are essential for understanding the operation of wave energy converters. The proposed spectral-domain wave-to-wire model significantly reduces computational load while maintaining good accuracy through stochastic linearization. Nonlinear effects in both hydrodynamic and electrical stages are considered. The model is validated against a nonlinear time-domain wave-to-wire model and shows good agreement with a relative error of around 2%.
APPLIED OCEAN RESEARCH
(2023)
Article
Engineering, Marine
Yu Wu, Chaohua Zhang, Fang Wang, Chao Yang
Summary: Currently, research on pressure hull safety focuses on constitutive models and evaluation models for fatigue life prediction, but neglects the methods for damage identification and quantitative evaluation of pressure hulls. This study introduces an eddy current thermal imaging method to detect micro-cracks in deep-sea spherical pressure hulls. A theoretical model is established using electromagnetic theory and heat transfer theory to analyze the temperature distribution around the cracks. A pulsed eddy current thermal imaging testing system is used to test a defective titanium alloy specimen with the same material and welding as the deep-sea spherical pressure hull. This paper discusses the possibility of using this method in pressure hulls for micro-crack damage identification and quantitative evaluation.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Marine
Kelin Wang, Oleg Gaidai, Fang Wang, Xiaosen Xu, Tao Zhang, Hang Deng
Summary: In this study, a method for predicting the power response of floating offshore wind turbines (FOWTs) using an artificial neural network algorithm is proposed. The method can accurately predict the extreme response statistics of FOWTs under realistic operating conditions by using a high-quality operational dataset and the inverse first-order reliability method.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Green & Sustainable Science & Technology
Oleg Gaidai, Fang Wang, Yihan Xing, Rajiv Balakrishna
Summary: Wind turbines and their associated parts are susceptible to various cyclic stresses, making research on the resilience of dynamic systems crucial. The method described in this study is beneficial for multidimensional structural responses. It accurately predicts the probability of system failure in the case of a measurable structural reaction, and offers a novel approach for structural reliability that doesn't require a multidimensional reliability function in numerical simulations.
ADVANCED ENERGY AND SUSTAINABILITY RESEARCH
(2023)
Article
Engineering, Marine
Oleg Gaidai, Yu Cao, Yihan Xing, Rajiv Balakrishna
Summary: The research investigates the motion response and hydrodynamic wave loads of a deep-water Tension Leg Platform (TLP), focusing on the effects of wave sum frequency on constrained modes of heave, roll, and pitch. The stochastic TLP structural response in a random sea state was accurately calculated using a Volterra series representation of the TLP corner vertical displacement. The wave loading was evaluated using the second-order diffraction code WAMIT and applied to a linear damped mass-spring model representing the dynamic system. A novel deconvolution approach was used to determine the platform displacement response at the design low probability level.
INTERNATIONAL JOURNAL OF NAVAL ARCHITECTURE AND OCEAN ENGINEERING
(2023)
Article
Engineering, Marine
Alba Ricondo, Laura Cagigal, Beatriz Perez-Diaz, Fernando J. Mendez
Summary: This research presents a site-specific metamodel based on the SWASH numerical model simulations, which can predict coastal hydrodynamic variables in a fast and efficient manner. The metamodel uses downscaled and dimensionality reduced synthetic database to accurately reproduce wave setup, wave heights associated with different frequency bands, and wave runup. This method has great potential in coastal risk assessments, early warning systems, and climate change projections.
Article
Engineering, Marine
Xiao Yu, Wangjun Ren, Bukui Zhou, Li Chen, Xiangyun Xu, Genmao Ren
Summary: This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s-1. The results showed that coral sand had significantly higher energy absorption capacity than silica sand due to its higher compressibility. The study findings suggest that using poorly graded coral sand can improve its energy absorption capacity.
Article
Engineering, Marine
Jingxi Zhang, Junmin Mou, Linying Chen, Pengfei Chen, Mengxia Li
Summary: This paper proposes a cooperative control scheme for ship formation tracking based on Model Predictive Control. A predictive observer is designed to estimate the current motion states of the leader ship using delayed motion information. Comparative simulations demonstrate the effectiveness and robustness of the proposed controller.
Article
Engineering, Marine
Yu Yao, Danni Zhong, Qijia Shi, Ji Wu, Jiangxia Li
Summary: This study proposes a 2DH numerical model based on Boussinesq equations to investigate the impact of dredging reef-flat sand on wave characteristics and wave-driven current. The model is verified through wave flume experiments and wave basin experiments, and the influences of incident wave conditions and pit morphological features on wave characteristics are examined.
Article
Engineering, Marine
Jayanta Shounda, Krishnendu Barman, Koustuv Debnath
Summary: This study investigates the double-average turbulence characteristics of combined wave-current flow over a rough bed with different spacing arrangements. The results show that a spacing ratio of p/r=4 offers the highest resistance to the flow, and the double-average Reynolds stress decreases throughout the flow depth. The advection of momentum-flux of normal stress shows an increase at the outer layer and a decrease near the bed region after wave imposition. Maximum turbulence kinetic energy production and diffusion occur at different layers. The turbulence structure is strongly anisotropic at the bottom region and near the outer layer, with a decrease in anisotropy observed with an increase in roughness spacing.
Article
Engineering, Marine
Meng Zhang, Lianghui Sun, Yaoguo Xie
Summary: The research proposes a method for online identification of wave bending and torsional moment in hull structures. For structures without large openings, the method optimizes sensor positions and establishes a mathematical model to improve accuracy. For structures with large openings, a joint dual-section monitoring method is proposed to simultaneously identify bending and torsional moments in multiple key cross sections.
Article
Engineering, Marine
Longming Chen, Shutao Li, Yeqing Chen, Dong Guo, Wanli Wei, Qiushi Yan
Summary: This study investigated the dynamic response characteristics and damage modes of pile wharves subjected to underwater explosions. The results showed that the main damaged components of the pile wharf were the piles, and inclined piles had a higher probability of moderate or more significant damage compared to vertical piles. The study also suggested that replacing inclined piles with alternative optimized structures benefits the blast resistance of pile wharves.
Article
Engineering, Marine
I. -C Kim, G. Ducrozet, V. Leroy, F. Bonnefoy, Y. Perignon, S. Bourguignon
Summary: Previous research focused on the accuracy and efficiency of short-term wave fields in specific prediction zones, while we developed algorithms for continuous wave prediction based on the practical prediction zone and discussed important time factors and strategies to reduce computational costs.
Article
Engineering, Marine
Hang Xie, Xianglin Dai, Fang Liu, Xinyu Liu
Summary: This study investigates the load characteristics of a three-dimensional stern model with pitch angle through a drop test, and reveals complex characteristics of pressure distribution near the stern shaft. The study also shows that the vibration characteristics of the load are influenced by the drop height and pitch angle, with the drop height having a greater effect on the high-frequency components.
Article
Engineering, Marine
Hangyuan Zhang, Wanli Yang, Dewen Liu, Xiaokun Geng, Wangyu Dai, Yuzhi Zhang
Summary: The deep-water bridge is more vulnerable to earthquake damage than the bridge standing in air. The larger blocking ratio has a significant impact on the added mass coefficient, which requires further comprehensive study. The generation mechanism of block effect is analyzed using numerical simulation software ANSYS Fluent. The results show that the recirculation zone with focus reduces the pressure on the back surface of the cylinder, resulting in the peak value of in-line force not occurring synchronously with the peak value of acceleration. The change in position and intensity of the recirculation zone with focus, as well as the change in water flow around the cylinder surface, are identified as the generation mechanism of the block effect, which has a 10% influence on the hydrodynamic force. The changing rule of the added mass coefficient with blocking ratio is discussed in detail, and a modification approach to the current added mass coefficient calculation method is suggested. Physical experiments are conducted to validate the modification approach, and the results show that it is accurate and can be used in further study and real practice.
Article
Engineering, Marine
Golnesa Karimi-Zindashti, Ozgur Kurc
Summary: This study examines the performance of an in-house code utilizing a deterministic vortex method on the rotation of circular and square cylinders. The results show that rotational motion reduces drag forces, suppresses fluctuating forces, and increases lift forces. The code accurately predicts vortex shedding suppression and identifies the emergence of near-field wakes in the flow over rotating square cylinders.
Article
Engineering, Marine
George Dafermos, George Zaraphonitis
Summary: The survivability of damaged ships is of great importance and the regulatory framework is constantly updated. The introduction of the probabilistic damage stability framework has rationalized the assessment procedure. Flooding simulation tools can be used to investigate the dynamic response of damaged ships.
Article
Engineering, Marine
Xuyue Chen, Xu Du, Chengkai Weng, Jin Yang, Deli Gao, Dongyu Su, Gan Wang
Summary: This paper proposes a real-time drilling parameters optimization method for offshore large-scale cluster extended reach drilling based on intelligent optimization algorithm and machine learning. By establishing a ROP model with long short-term memory neurons, and combining genetic algorithm, differential evolution algorithm, and particle swarm algorithm, the method achieves real-time optimization of drilling parameters and significantly improves the ROP.
Article
Engineering, Marine
Sung-Jae Kim, Chungkuk Jin, MooHyun Kim
Summary: This study investigates the dynamic behavior of a moored submerged floating tunnel (SFT) under tsunami-like waves through numerical simulations and sensitivity tests. The results show that design parameters significantly affect the dynamics of the SFT system and mooring tensions, with shorter-duration and higher-elevation tsunamis having a greater impact.
Article
Engineering, Marine
G. Clarindo, C. Guedes Soares
Summary: Environmental contours are constructed using the Inverse-First Order Reliability Method based on return periods. The paper proposes the use of the Burr distribution to model the marginal distribution of long-term significant wave heights. The newly implemented scheme results in different environmental contours compared to the reference approach.