bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Toolbox for Towing Dynamics Predictions for Floating Offshore Wind Turbines: Validation and Parametric Study
Authors: Davis Samuel , Verma Amrit , Viselli Anthony , Allen Christopher 
Published: August 2024

Abstract
The floating offshore wind industry is growing rapidly, with increased capacity goals and expanding commercial project opportunities in the coming years. An important marine operation related to floating offshore wind is towing. The safety and cost of a tow operation are highly dependent on the choice of a suitable tug and tow speed, as well as the forces expected to act on the towing system. In the presence of waves, significant dynamic towline tensions can be experienced that may cause the towline to break. Therefore, predicting the tensions in the towline is important for efficient design and planning of the towing system.
The present paper describes a methodology for towing dynamics predictions and is implemented into MATLAB as a toolbox for planning future tow operations. The proposed methodology is able to (a) estimate the bollard pull requirements and static towing forces crucial for planning the tow operation; as well as (b) predict the mean and dynamic towline tensions in the presence of a given sea state. Two separate analyses are performed. In the first analysis, the towline tension predictions from the toolbox are validated against measured towline tension data from the University of Maine’s VolturnUS 1:8 deployment together with the results from a time domain model developed in OrcaFlex. In the second analysis, a parametric study is performed using the toolbox. The results of the study show the toolbox was able to closely predict the measured static and dynamic towline tensions. In addition, the effect of propeller race interactions with the towed floating offshore wind turbine was shown to significantly impact the predicted towline tension.
Application of a Geometric Common Model Modeling Method Based on Skeleton Model in Lashing Bridge Design
Authors: Xu Sihao , Li Hairui , Tang Xiaoyang , Wang Deyu 
Published: August 2024

Abstract
The lashing bridge is considered one of the core technologies in container ships. It is used to secure containers above the main deck and transfer the loads generated by container stacking to the ship’s structure. Its design is influenced by various factors. Therefore, it faces challenges in terms of design changes and collaborative design. In addition, lashing bridge design not only requires generating drawings and bill of material (BOM), but also involves activities such as finite element analysis and virtual prototyping validation, all of which have different geometric requirements. This paper proposes a product structure built upon the concept of geometric common modeling, leveraging skeleton models within the CATIA V6. The study underscores the pivotal role of skeleton models in organizing and linking all design information, facilitating efficient interaction between different models. Practical lashing bridge applications illustrate the effectiveness of this methodology. Moreover. the product structure based on skeleton models also embodies the philosophies of top-down and concurrent engineering. This method not only achieves geometric common modeling but also holds promise for broader applications, offering valuable insights for integrated design and serving as a beneficial reference for complex product design methodologies.
Influence of Bag Shapes on the Hydrodynamics of Subsea Filter Unit in Power Cable Protection
Authors: Tong Feifei , Griffiths Terry , Draper Scott , An Hongwei , Cheng Liang 
Published: August 2024

Abstract
Filter units (FUs), which resemble cylindrical mesh bags filled with rock aggregates, are commonly used for scour protection and secondary stabilization of subsea infrastructure, such as subsea power cables in offshore wind farms. A key consideration in the stability design of the FUs is the assessment of hydrodynamic drag, inertia, and lift forces acting on the FUs. These forces’ magnitude is expected to be influenced by the as-laid geometric configuration of the FUs. This study explores a range of bag configurations to gain insights into the hydrodynamics of FU bags, which include (i) a configuration derived from field observations, (ii) a configuration generated from a 3D scan of a model-scale FU used in laboratory testing, an idealized hemisphere configuration and (iv) an idealized configuration of an ice hockey puck. The study also examines various flow conditions, including steady flow and oscillatory flow induced by surface waves. To enable a meaningful comparison, the same volume of the FUs with different configurations was used in the analysis. The findings indicate that the hemispherical FU experiences the least drag forces and is much less likely to roll under steady flow conditions. These results contribute novel insights into the understanding of hydrodynamic forces acting on FUs. It is expected that this understanding will enhance the stability design of FUs for various metocean conditions, consequently reducing the risks of subsea power cable damage resulting from cable-FU interactions.
Mechanistic Study on the Stabilization of CO2 Oil-Based Foam by a Novel Compound Surfactant
Authors: Wang Zhoujie , Li Songyan , Li Shaopeng , Li Minghe 
Published: August 2024

Abstract
The effectiveness of CO2 oil-based foam in conventional and unconventional oil and gas development, as well as CO2 storage, relies on its stability. This study delves into the gas-liquid surface properties and liquid film behavior of a compound surfactant FS oil-based foam system, with a focus on understanding the mechanisms influencing its stability. The investigation reveals that the viscoelastic modulus of the FS surfactant system initially rises and then stabilizes with increased concentration, reaching a peak of 15.43 mN/m at 1.5 wt%. In the FS oil-based foaming system, the inhibition of sliding between liquid molecules enhances resistance to external deformation, promoting stability. Observing the liquid film of FS oil-based foam, color transitions signify evolving film thickness. The film initially displays various colors, gradually shifting from cyan and purple to deep blue and brown. As the film stratifies, forming dark domains that expand and eventually lead to rupture, FS significantly prolongs thinning time and reduces film thickness. At 2 wt% FS concentration, the foam rupture time is maximized at 4550 s. The presence of surfactant molecules forming a molecular layer in the liquid film strengthens and toughens the film, enhancing durability against external forces. This research suggests that the FS oil-based foam system with a 2 wt% concentration exhibits superior stability. Insights gained from this study contribute to the strategic use of oil-based foam, offering potential benefits for enhancing oilfield development efficiency and supporting carbon reduction goals.
Sensitivity Analysis of Different Welding Parameters on the Vibration Characteristics of Butt-Welded Plates
Authors: Chen Ziheng , Lin Yongshui , Feng Xiliang , Gan Jin , Wu Weiguo 
Published: August 2024

Abstract
To investigate the sensitivity of different welding parameters on the vibration characteristics, this study employs a typical butt-welded plate structure for experimental testing and numerical analysis. A sensitivity analysis method for various welding parameters on vibration characteristics is also introduced to investigate the impact of welding parameters on plate structures. Initially, the accuracy of the numerical calculation method is validated by comparing the X-ray diffraction (XRD) measurements and modal tests of flat-plate butt structures with the numerical simulation results. Subsequently, the thermal elastic-plastic finite element (TEP-FE) method is utilized to calculate the welding residual stress of plate structures under different welding parameters. Finally, the vibration calculation of plate structures with different welding parameters is carried out based on the finite element method (FEM), and sensitivity analysis is applied to identify the primary influence parameter on vibration characteristics among the various welding parameters. The results demonstrate a stable range for transverse and longitudinal residual stress changes when welding parameters vary. It is possible to optimize welding parameters within this range. The varied welding parameters significantly affect the natural frequency and vibration characteristics of the plate structure, leading to the discovery of remarkable phenomena. As the order of the natural frequency increases, so does the amount of variation, with a maximum change rate of up to 10%. Through sensitivity analysis, the natural frequency is more sensitive to changes in welding voltage, while the sensitivity to changes in welding current should be noticed. The amount of variation and sensitivity coefficients of the total vibration acceleration level and amplitude of vibration acceleration increase with increasing welding parameters and are more sensitive to changes in welding voltage. Through sensitivity analysis, it is feasible to refine the vibrational qualities of the butt-welded plate structure by adapting relevant welding and numerical simulation input parameters. Consequently, considering the influence of welding, this study is a valuable resource for optimizing structural vibrations.
Fluid-Structure Coupling Study of Ship-Ice Interaction Based on a Mixed-Parameter Cohesive Method
Authors: Gu Zhuhao , Lu Yu , Zhu Xianghang , Zhang Lizhi , Zhang Shuoyan 
Published: August 2024

Abstract
Ship-ice interaction is an important engineering issue in the polar region. Choosing the appropriate sea ice simulation method in the simulation of ship-ice collision will have a greater impact on the collision force of the ship hull. Sea ice is a complex solid. If you want to truly Simulating actual sea ice properties presents significant challenges. In order to more accurately simulate the interaction of ship ice in actual navigation, this study uses the nonlinear explicit finite element method for calculation, and establishes a sea ice calculation model based on the piecewise linear plastic constitutive model. The cohesion is used as a calculation method for sea ice fracture, the hull uses an elastic-plastic constitutive model, and the ALE method is finally used to solve the complex fluid-solid coupling problem of the ship, water, and ice phases. By comparing the simulations of cohesive models with the same parameters and hybrid parameters, the calculation results show that during the ship ice fluid-solid coupling calculation process, the hybrid cohesive simulates the circumferential and longitudinal crack forms of sea ice better, and the ice load is consistent with The hull stress is closer to the empirical formula. This study provides a useful reference for improving ice operations and offshore structure design in Arctic shipping, and has great research significance for improving ship performance and safety.
Static Obstacle Avoidance With Path Following of ASVs by Using Twin Delayed Deep Deterministic Policy Gradients
Authors: Thirumurugan Vishnu , Rajendran Suresh , Somayajula Abhilash Sharma 
Published: August 2024

Abstract
In the field of autonomous surface vehicle (ASV) navigation, ensuring safety is paramount, necessitating an advanced collision avoidance system. This study focuses on the Twin Delayed Deep Deterministic Policy Gradients (TD3) algorithm, which operates in a continuous action space. We introduce an innovative epsilon-greedy exploration strategy for TD3, improving its performance by mitigating per-update errors and effectively balancing exploration and exploitation phases. The reward function is meticulously designed to reduce both cross-track and heading errors, exemplified using the L3 model of the KVLCC2 tanker, with an emphasis on minimizing rudder deflections. Error assessments are based on the Line of Sight (LOS) algorithm. The primary goal of this research is to enhance ASV navigation’s safety and efficiency by integrating collision avoidance of static obstacle with path-following capabilities through deep reinforcement learning. The developed model adeptly avoids collisions, continuously refining its policy to adapt to diverse conditions of static obstacles while prioritizing safety and optimal navigation. The study’s success lies in effectively developing, training, and testing a neural network architecture tailored for evading static obstacles, showcasing significant advancements in ASV navigational technologies.
Development Review of Open Water Economical Floating Photovoltaic Platform
Authors: Fu Qiang , Wang Wenping , Li Dejiang , Li Shumin , Chen Kuiying , Zheng Long , Wang Chuanwen , Chen Peng 
Published: August 2024

Abstract
Building up safe, reliable, green photovoltaic (PV) power generation plant has become one key national development direction among China new energy industry. Nowadays, the available land for deploying PV is getting shorter, plus, national restrictions on deploying PV in lakes, reservoirs and other freshwater areas are also announced to ensure further environmental protection. Therefore, deploying floating PV platform on the seashore open water is emerging as national level urgent needs.
A four body interconnected platforms (400kW) has been installed at 4km away from coastline of Yantai, China for concept proof and data collection purpose. One bamboo-based composite material floating platform is also installed nearby for material testing. Together with a bottom seating steel platform carrying various kind of testing equipment, the first Offshore PV Demonstration Base dedicated for PV testing under sea environment has been established by CIMC Raffles in China.
This paper is a project development review for our semi-submersible type floating platforms. It states our novel weight optimization concepts in various aspects. Special highlight is a fully coupled time-domain hydro-structure-mooring multi-body analysis workflow, including composite material modelling, has been used to give an accurate global strength analysis. In addition, bamboo-based composite material platform, a totally lightweight and low-carbon platform is briefly introduced.
Our illustrated experience covers design, fabrication, installation, and operation with field monitoring. This project review gives readers a project reference for assessment to any seashore floating PV platform. Our continuous research for developing a lightweight and low-carbon floating platform shall be one recommended option for future.
Dynamic Responses of the Tower and Blades on a Spar-Type Floating Wind Turbine Under Freak Waves
Authors: Li Yan , Li Haoran , Cui Yiwen , Su Ouming , Li Guoyan , Tang Yougang 
Published: August 2024

Abstract
A floating offshore wind turbine would be subjected to various abnormal waves. Among them, the freak waves which have high energy may suddenly enlarge the stress and deformation of the upper flexible structures such as the tower and blades. The numerical model of a Spar-type floating wind turbine is established, the freak waves are numerically generated and modulated. Fluctuated freak waves and elevated freak waves are obtained based on the phase angle modulation method. The dynamic performances of the wind turbine under the freak waves are simulated in the time domain, and the internal loads of the tower and blades are analyzed. The results of the tower load responses under the different freak waves show that fluctuated freak waves have a significant effect on the shear force and torque. When fluctuation rises by 15.0 %, shear force increases by 15.0 %, and torque by 9.3 %. Elevated freak waves have slight effects on the torque. The fluctuated freak waves have an obvious effect on the blades. When fluctuation increases by 15%, shear force increases by 8.72 %, and torque by 4.09 %. The torque moment of the blade root is not significantly affected by the change of different freak waves (less than 5%).
Development of Low Energy Consumption Motion Stabilized Platform for Offshore Wind Observations Floating Platform
Authors: Yamamoto Yusuke , Taniguchi Tomoki , Katayama Toru 
Published: August 2024

Abstract
It is necessary to obtain accurately actual wind state at the sea where offshore wind farm will be constructed, in order to guarantee its safety and profitability. In this study, it is proposed that motion of the non-restoring counter-weight type motion stabilized platform on a buoy is made smaller than that of the buoy by using a linear damper to get regenerative energy and skyhook spring and damper controlled by using the regenerative energy. Then, the energy consumption and motion reduction performance of the system is evaluated, and it is tried by system optimization that the energy balance becomes positive.
Application of Hierarchical Analyst Domino Evaluation System (HADES) in Floating Offshore Wind Farm (FOWF) Operation Stage
Authors: Li Yihong , Hu Zhen-Zhong , Li Binbin 
Published: August 2024

Abstract
In light of the escalating greenhouse effect and the increasing frequency of extreme weather events, the global spotlight has shifted towards the development of green energy solutions. Notably, Floating Offshore Wind Turbines (FOWTs) have gained prominence as a high-tech innovation in harnessing wind resources in deep-sea field. However, an expanded perspective that encompasses entire wind farms necessitates a more comprehensive approach to risk assessment and safety management.
This paper introduces the application of the Hierarchical Analyst Domino Evaluation System (HADES), originally designed for offshore oil and gas facilities decommissioning, to assess the domino risk of the Floating Offshore Wind Farm (FOWF) situated near the Wanning Sea area, Hainan, China. The assessment includes scenarios involving navigating vessels collisions, typhoons, storm surges, and large waves, which can lead to accidents such as capsizing, deviation, and structural damage. HADES offers a Quantitative Risk Assessment (QRA) framework that hierarchically models the development of domino accidents, providing a clear visualization of the accident progression. Unlike other domino risk assessment methods, HADES incorporates Frequentist Approach to reconstruct the trigger mechanisms and propagation logic of these accidents. HADES simplifies calculations and reduces the reliance on extensive historical data. Through the analysis of accident scenarios, probabilities, and consequences, this study aims to address the concerns of FOWF operators regarding the layout, operation, and monitoring of FOWTs. The results of the analysis indicate that due to the lower integration and density of equipment in FOWFs, domino incidents are unlikely to occur and propagate. The majority of domino events are caused by external structural failures of the FOWTs themselves and collisions with vessels within the wind farm area. The focus of research on domino accident assessment for FOWFs should be placed on the reliability of FOWT components such as blades, towers, floating foundations, and anchor chains, as well as on strategies to avoid collisions with vessels. This study enhancing our understanding and preparedness for potential accidents in this dynamic and critical sector.
Evaluation of a Multi-Turbine Floating Platform Concept Considering Wake Effect
Authors: Li Shen , Brennan Feargal 
Published: August 2024

Abstract
Floating offshore wind currently implements a one-turbine-one-platform strategy. A nominal offshore wind farm with 1GW capacity will require more than 60 floating platforms, 200 mooring lines and complex distributed power take-off infrastructure, leading to costly inspection and maintenance. Hence, upscaling the one-turbine-one-platform strategy to GW-scale floating offshore wind array represents a major challenge. A multi-turbine shared platform approach has the potential to reduce this complexity and cost. However, to space the turbines effectively and prevent turbine interference on power production due to wake effect, these structures need to be of unconventional size, i.e., Very Large Floating Structures (VLFS). The unprecedented size of VLFS imposes techno-economic challenges such as demanding structural integrity requirement and significant increase of material cost. In view of this, this paper evaluates the trade-off between the mitigation of wake effect and the cost-effectiveness of platform’s structural design. Constrained by structural integrity considerations, a multi-objective optimisation is completed in which the Pareto front of maximum power output and minimum total cost is evaluated. A Jensen’s single wake model is employed to assess the impact of turbine interference. Comparison with a previously developed reference design with 600 metres’ total length indicates the potential to extend the length by 200 metres, enhancing the power output without compromising cost-effectiveness.
Identification Modeling of Ship Maneuvering Motion Based on Echo State Gaussian Process
Authors: Liu Si-Yu , Zou Zao-Jian , Zou Lu 
Published: August 2024

Abstract
The mathematical model of ship maneuvering motion is a crucial foundation for both prediction of ship navigation state and automatic control of ship motion. This paper proposes a practical and robust nonparametric identification method based on echo state Gaussian process (ESGP) to establish the nonparametric model of ship maneuvering motion. The traditional echo state networks (ESNs) and basic Gaussian processes (GPs) have found successfully applications in nonparametric modeling and time-series forecasting. The proposed method combines the strengths of both ESN and GP approaches. On the one hand, it offers a more robust alternative to conventional reservoir computing networks; on the other hand, it can directly generate confidence intervals for prediction results. The KVLCC2 ship model is taken as the object of this research. The datasets collected from several standard and nonstandard zigzag maneuvers of free-running model, which are provided by SIMMAN 2008, are used as training and testing data. To assess the robustness and generalization ability of the established nonparametric model, the prediction results of the ESGP method are compared with the experimental data. It is shown that the ESGP method proposed in this paper can achieve high prediction accuracy and provide a measure of credibility for the output results, which makes it more practical and applicable for modeling and prediction of ship maneuvering motion.
An Experimental Investigation on Vortex-Induced Vibration of Double Risers in Tandem Under Bidirectionally Sheared Flow
Authors: Bai Yingli , Zhang Mengmeng , Fu Shixiao , Chu Yaopeng , Fu Xuepeng , Ren Haojie , Xu Yuwang 
Published: August 2024

Abstract
The interfering characteristics of vortex-induced vibration (VIV) responses for tandem double risers under the recently discovered bidirectionally sheared flow are unclear. To reveal the interfering VIV characteristics in bidirectionally sheared flow, a rotating test rig was built to simulate bidirectionally sheared flow in the ocean basin. A series of VIV experiments for two scaled riser models were carried out, which included a single riser and tandem double risers with two different center-to-center spacing (3D and 5D). Then the modal superposition method was used to reconstruct the VIV displacements in cross-flow (CF) direction and the drag displacement. Furthermore, the drag coefficient was identified and analyzed. Results indicate that the VIV frequency of tandem double risers remains consistent at same spacing. When the reduced velocity (Vr) is in range of 5.0 to 18.0, the VIV amplitude of tandem double risers is basically same, but slightly smaller than that of the single riser. However, the VIV amplitude of riser 2 is significantly higher than that of riser 1 at Vr &gt; 18.0. Moreover, it is found that the overall average drag coefficient in tandem double risers is lower than 1.38 of single riser, with values of 1.25 (S = 3D) and 1.33 (S = 5D) respectively.