bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring the Technical Boundaries in Upscaling Floating Offshore Wind Turbines
Authors: Janocha Marek Jan , Lee Chern Fong , Wen Xueliang , Ong Muk Chen , Raunholt Lars , Helgaland Larsen Ørjan , Søyland Svein 
Published: August 2024

Abstract
Recent advancements in offshore wind turbine technology have led to a rapid increase in the size of turbines. In the early 1980s, wind turbines had a relatively small power rating of 50 kW with rotor diameters of around 15 meters. This size grew significantly, reaching 18 MW with 260-meter rotor diameters currently under construction. The market is transitioning to even larger turbines, with a power rating expected to achieve 22 MW by 2025. This trend of increasing turbine sizes shows no signs of reaching its limit. However, it is anticipated that the cost curve will break at some point due to material limitations necessary to withstand increasing forces and moments from the environmental loads and exponentially increasing mass of the components. For floating offshore wind turbines specifically, the design complexity increases as these systems comprise of both a turbine and a floating foundation. Innovations in this area include using advanced composite materials for larger components such as blades and towers, high-fidelity numerical models for structural optimization to mitigate excessive dynamic response and employing unconventional solutions such as combined wind and wave energy conversion systems or multirotor wind turbines. Recent developments in wind turbine systems have also seen improvements in control systems and generator design, including direct-drive and multi-generator solutions. To further increase electrical energy production from wind turbines in the future, it is necessary to develop strategies that reduce costs through technological innovation, enhance performance and efficiency, and decrease maintenance, operation, and manufacturing costs. The evolution of wind turbine technology plays a pivotal role in the global wind power generation landscape, and the trend toward larger turbines is a significant aspect of this evolution. The present paper focuses on the theoretical technical limits of floating wind turbine upscaling and determining the optimal turbine size for minimizing energy costs.
A Simplified Formulation of the Linear Design VWBM Based on IACS Rec. No. 34 Rev.2
Authors: Mikulić Antonio , Ćorak Maro , Parunov Joško 
Published: August 2024

Abstract
A simplified formulation for the linear part of the design vertical wave bending moment (VWBM) at midship is proposed. The formulation is based on the computation of the long-term VWBM for 25 ships of diverse types, using assumptions embedded in the new IACS Rec. No. 34 Rev.2. Transfer functions of VWBM at midship are calculated using semi-analytical Closed-Form Expressions. Long-term probability distributions of VWBM are fitted by the two-parameter Weibull probability function. Weibull scale and shape parameters are then approximated by linear multiple regression analysis, where the main ship particulars are taken as the regression parameters. As the most probable extreme value according to the IACS Rec. No. 34 Rev.2 is determined for the return period of 25 years, the average zero crossing response period in the ship design lifetime is also subjected to the linear regression analysis. Design VWBM is then calculated as the most probable extreme value by the proposed formulation and compared to the results of the long-term distribution. The results indicate that the regression equations can accurately approximate the results of the long-term distribution. Although numerical comparison with the existing Rule formulation is not the aim of the study, results are nevertheless compared with the VWBM from IACS UR S11 and UR S11A. It was found that the design VWBM from this study is lower compared with the existing IACS rule formulations. The proposed approach can be considered as the rule formulation of design VWBM and as a surrogate model of extreme VWBM for ship structural reliability analysis.
Variational Autoencoders for Exteroceptive Perception in Reinforcement Learning-Based Collision Avoidance
Authors: Larsen Thomas Nakken , Barlaug Eirik Runde , Rasheed Adil 
Published: August 2024

Abstract
Modern control systems are increasingly turning to machine learning algorithms to augment their performance and adaptability. Within this context, Deep Reinforcement Learning (DRL) has emerged as a promising control framework, particularly in the domain of marine transportation. Its potential for autonomous marine applications lies in its ability to seamlessly combine path-following and collision avoidance with an arbitrary number of obstacles. However, current DRL algorithms require disproportionally large computational resources to find near-optimal policies compared to the posed control problem when the searchable parameter space becomes large. To combat this, our work delves into the application of Variational AutoEncoders (VAEs) to acquire a generalized, low-dimensional latent encoding of a high-fidelity range-finding sensor, which serves as the exteroceptive input to a DRL agent. The agent’s performance, encompassing path-following and collision avoidance, is systematically tested and evaluated within a stochastic simulation environment, presenting a comprehensive exploration of our proposed approach in maritime control systems.
Digital Twin for Wind Energy: Latest Updates From the NorthWind Project
Authors: Rasheed Adil , Stadtmann Florian , Fonn Eivind , Tabib Mandar , Tsiolakis Vasileios , Panjwani Balram , Johannessen Kjetil Andre , Kvamsdal Trond , San Omer , Tande John Olav , Barstad Idar , Christiansen Tore , Rishoff Elling , Frøyd Lars , Rasmussen Tore 
Published: August 2024

Abstract
NorthWind, a collaborative research initiative supported by the Research Council of Norway, industry stakeholders, and research partners, aims to advance cutting-edge research and innovation in wind energy. The core mission is to reduce wind power costs and foster sustainable growth, with a key focus on the development of digital twins. A digital twin is a virtual representation of physical assets or processes that uses data and simulators to enable real-time forecasting, optimization, monitoring, control and informed decision-making. Recently, a hierarchical scale ranging from 0 to 5 (0 - Standalone, 1 - Descriptive, 2 - Diagnostic, 3 - Predictive, 4 - Prescriptive, 5 - Autonomous has been introduced within the NorthWind project to assess the capabilities of digital twins. This paper elaborates on our progress in constructing digital twins for wind farms and their components across various capability levels.
Optimizing Aluminum Alloys for Dynamic Cables in Floating Wind Energy Transmission
Authors: Johanson Audun , Viespoli Luigi 
Published: August 2024

Abstract
Floating wind energy presents a promising opportunity to harness vast wind resources that remain inaccessible using today’s bottom-fixed offshore wind technology. Transmitting the electricity generated by floating wind turbines to shore lies in dynamic cables. However, the implementation of these cables is beset by technological and knowledge gaps, leading to increased costs compared to conventional static subsea cables. One significant challenge is the use of aluminum as a conductor material. Aluminum offers a more cost-effective alternative to copper, which can potentially reduce the overall cost of dynamic cables. High-conductivity aluminum grades like AA1350/70 exhibit excellent electrical properties but are hindered by low mechanical characteristics, especially in terms of creep and fatigue strength. Alloys that combine high strength and conductivity, such as AA6101 with appropriate aging treatment, offer a reasonable yield strength, but also 10–15 % reduced conductivity. and conductivity. In this study, we explore a subset of the AA1120 series aluminum alloy with tailored chemistry to improve fatigue strength while maintaining excellent conductivity. Our results reveal a significant enhancement in fatigue properties compared to AA1370, with the optimized alloy exhibiting fatigue characteristics akin to copper. These findings emphasize the importance of meticulous alloy and processing design for the safe and cost-effective integration of aluminum conductors into dynamic cable systems.
Numerical Investigation of Manoeuvring Performance of an Icebreaking Tanker in Ice-Prone Baltic Sea Environments
Authors: Panahi Saeid , von Bock und Polach Rüdiger Ulrich Franz , Abdel-Maksoud Moustafa , Oberhagemann Jan 
Published: August 2024

Abstract
The maritime trade and activities in regions with ice-covered waters such as the Arctic, Antarctica, the Baltic Sea, the Caspian Sea and the Great Lakes are expected to experience growth in the near future, mainly influenced by factors like: increased dry bulk and cargo freight in Arctic regions, rising tourism in Arctic and Antarctic waters, and increased exploitation and transport of oil and gas in Arctic areas.
Most importantly, global warming — particularly in the North Pole — is opening new navigation routes through ice melting, affecting susceptible ecosystems and making previously inaccessible areas more navigable [1]. This highlights the need for a deeper understanding of Ship-Ice Interaction (SII) and manoeuvring performance in ice-infested waters. For a vessel advancing in ice, the primary focus pertains to the prediction of the ice resistance; however, the transverse force and turning moment are also of significance contemplating the manoeuvrability aspect whilst in turning circumstance.
This paper focuses on developing a numerical model to simulate SII and ship manoeuvres in level ice. The model integrates existing semi-empirical formulas for calculating ice-pertinent forces and moments, and a coefficient-based model (by the Taylor series expansion) for hydrodynamic forces. Key findings indicate the Lindqvist method’s effectiveness in predicting ice resistance, and confirm the reliability of the turning circle manoeuvre (in open water) with the experimental data of Wolff [2]. Nonetheless, to improve the accuracy of the turning circle manoeuvre in ice, it is imperative to have access to all the characteristics of the model tests and ice distribution in the ice tank.
Design of Cement Sheaths in Offshore Oil Wells Based on Structural Reliability
Authors: Estrela Gabriela Alves , de Sousa Fernando Jorge Mendes , Lopes Guilherme Kronemberger , Sagrilo Luís Volnei Sudati , e Silva Ana Beatriz de Carvalho Gonzaga , Fairbairn Eduardo de Moraes Rego , de Andrade Henrique Conde Carvalho , Telles José Cláudio de Faria , de Siqueira Andréia Arenari , Reales Oscar Aurelio Mendoza , Carvalho Carlos Pessanha , da Silva Ingrid Ezechiello , Rocha José Marcelo Silva , Moreira Rafael Peralta Muniz 
Published: August 2024

Abstract
The design of cement sheaths in offshore oil wells is usually performed following a deterministic approach, which doesn’t consider explicitly the variability and uncertainties in material properties and loads. Cement properties can vary, for instance, due to the intrinsic nature of the cementation process. Load uncertainties are attributed to the random character of the loading environment or to inadequate knowledge of the physical phenomena associated with them.
The objective of this work is to present a reliability-based methodology for designing cement sheaths, which uses probability distribution functions to describe material properties and loads, obtained from several laboratory tests and from literature review, respectively. Reliability calculations were performed combining the FORM (First Order Reliability Method) and a dedicated structural analysis computer program developed at COPPE/UFRJ named as TENCIM-1D. The proposed methodology allows an easy determination of failure probabilities with low computational costs. The importance factors derived from FORM help to identify variables that deserve a better statistical description. These results will help the development of future research, setting priorities in new lab tests and field surveys. Additionally, this methodology can contribute to change the way cement sheaths are designed, considering explicitly the uncertainties in materials properties and loads.
Data Driven Identification and Model Predictive Control for a Catamaran Surface Vessel
Authors: Deogaonkar Vallabh , Ibrahim M. Mohammed , Vijayakumar Akash , Somayajula Abhilash 
Published: August 2024

Abstract
Autonomous Surface Vehicles (ASVs) have received increasing attention in various maritime applications over the years. Their ability to operate autonomously in complex and confined environments, such as narrow inland waterways, presents a unique set of opportunities and challenges. This paper presents a comprehensive study on the dynamics identification and subsequent development of a Model Predictive Controller (MPC) for a catamaran surface vessel. The catamaran surface vessel under investigation was fabricated in-house with a holonomic thruster configuration and a comprehensive sensor suite. This study focuses on experimental identification of a 3 degree of freedom maneuvering model of the fully actuated surface vessel. With a well-defined dynamic model in place MPC is designed for efficiently tracking a path while maintaing surge velocity. The MPC framework is chosen due to its ability to optimize control inputs over a finite prediction horizon, ensuring the catamaran follows desired trajectories while adhering to operational constraints and actuator constraints. This paper outlines a holistic study on the dynamics identification and MPC development of an ASV to impact a wide range of applications, from oceanographic research to coastal security, by providing a robust control framework that can navigate the challenges of dynamic marine environments.
Study on Fatigue Assessment Considering Mooring Chain Wear for Floating Offshore Wind Turbines
Authors: Takeuchi Takaaki , Kurokawa Kazuki , Nozoe Eisuke 
Published: August 2024

Abstract
For the achievement of a carbon-neutral society by 2050, floating offshore wind turbines (FOWTs) have high expectations, especially in regions deeper than a water depth of 60 m because of the vast potential in Japan. For station keeping of FOWTs, the application in such a region generally requires mooring chains. Since the reliability assessment of mooring chains is one of the key issues to ensure the integrity of FOWTs during the design life, the mooring design limit state shall be properly evaluated.
For investigation on the effect of wear and corrosion on fatigue damage, some researchers consider the only uniform decrease in chain diameter, which is insufficient to represent a change in the stress distribution due to local deformation. The local diameter loss could increase local stress and lead to the unexpected early failure of the mooring chain. In order to estimate the fatigue life accurately, it is necessary to estimate the local diameter loss due to the interlink wear considering the motion of floating structures. In this study, such fatigue assessment method is investigated by assuming the installation of UMaine VolturnUS-S reference platform developed for the IEA wind 15MW wind turbine at Ishikari Bay, Hokkaido, Japan. This is based on a method to estimate interlink wear quantitatively by finite element analysis considering the plastic deformation caused by the proof load test, and coupled dynamic analysis of a floating structure and mooring system using OpenFAST. As a result, the estimated wear amount at the fairlead has been much larger than the specified allowance. Additionally, from the estimated fatigue damage it has been found that mooring chains cannot withstand design life without replacement, and deterioration due to interlink wear and corrosion could lead to unexpected early failure of mooring chains.
High- and Mid-Fidelity Modeling Comparison for a Floating Marine Turbine System
Authors: Tran Thanh Toan , Ross Hannah , Wiley Will , Wang Lu , Sirnivas Senu 
Published: August 2024

Abstract
There is a lack of suitable numerical tools, particularly open-source tools, that can be used for designing and optimizing marine turbine systems. The National Renewable Energy Laboratory has added features to their widely used mid-fidelity wind turbine modeling code, OpenFAST, to enable modeling of axial-flow marine turbines. This necessitated the addition of several physical effects relevant to marine turbines that are neglected for wind turbines. These include buoyancy, added mass and inertial loads, wave-current superposition, and changes to the coordinate systems. This updated version of OpenFAST allows for the modeling of both fixed and floating marine turbines at a speed comparable to real time. While efficient for large sets of load cases and design studies, mid-fidelity codes make simplifying assumptions that may impact their accuracy. High-fidelity computational fluid dynamics (CFD) simulations can capture more flow effects with fewer assumptions and provide detailed body pressure mapping and flow-field information. It is important to compare predictions between mid-fidelity and high-fidelity codes, both to verify the models and to understand the limitations. A floating marine turbine system was modeled both with OpenFAST and with the commercial CFD code STAR-CCM+. The CFD model used a three-dimensional unsteady Reynolds-averaged Navier-Stokes solver for a volume-of-fluid numerical wave and current tank. The blade-resolved simulations used the sliding-interface technique for the spinning rotor and an overset grid to accommodate the rigid-body motion of the floating system. The mooring system was modeled with a custom coupling of the CFD solver with the open-source code MoorDyn. This improves upon the existing quasi-static catenary solver in STAR-CCM+, which lacks seabed contact or line-to-line connections. Simulation results for a floating marine turbine are compared between OpenFAST and CFD, highlighting the capabilities of the mid-fidelity code and identifying the areas where a high-fidelity approach is needed.
Vessel Motion During Side-By-Side Offloading: Comparison of Field Data and Numerical Model
Authors: Wang Yutao , Wolgamot Hugh , Zhao Wenhua , Draper Scott , Watson Phillip 
Published: August 2024

Abstract
The side-by-side (SBS) offloading operation is a conventional industry practice when an FLNG facility offloads liquid cargo onto carriers. There are several criteria for this operation to ensure safety and operability. Carrier motion during the SBS offloading has been studied extensively by either computational models or laboratory scaled models. Comparison between these results and full-scale measurements of vessel motions that are recorded during actual offloads has also been studied by JIPs and companies, but almost none of this is presently available in the public literature. This paper presents, for the first time, a vessel motion comparison between numerical model and field measurements. In particular, aspects which are challenging to model numerically, and therefore interesting to investigate in the comparison include roll motion, motions coupled to gap resonance, and motions coupled to sloshing.
Decision Support System for the Selection of Offshore Oil Wells Configuration
Authors: dos Santos Joaquim Rocha , León Chinchay Carlos Alberto , Martins Pereira de Abreu Danilo Taverna , Arguello Rodrigues Eric Tierre , Colombo Danilo , Ramos Martins Marcelo 
Published: August 2024

Abstract
Much of the hydrocarbon production in Brazil originates from offshore operations in pre-salt fields. The pre-salt fields are located more than 300 km from the coast, in water depths of around 2,000 meters, with reservoirs 7,000 meters from the sea surface. Operating in such conditions presents challenges regarding operational safety and keeping low downtime, guaranteeing a high financial return. A critical decision in developing these fields is choosing the best configuration for their wells, as in addition to the points already highlighted, maintenance in the pre-salt is also expensive. During oil well design, engineers suggest several configurations, leaving the field manager to choose the best options. An oil and gas operator is developing a decision support system to assist managers in this decision. This article deals with a software module — ReliaWell — that aims to calculate indicators of integrity (operations safety) and production equipment reliability (ensuring operation continuity). The article briefly presents the software requirements and the process of surveying the indicators to be considered, discusses the methodology adopted for the simulation models, and shows the system architecture and some screens, especially those for data entry and results output.
Development of Time Series Drilling Datasets for Stuck Pipe Prediction Using Volve Field Data
Authors: Bo Cao , Yu Song , Feng Xu , Fukang Peng 
Published: August 2024

Abstract
Numerous machine learning algorithms are applied in the oil and gas industry. However, the data used in these studies are difficult to obtain due to various limitations. Due to the lack of benchmark datasets, it is challenging to make performance comparisons across different algorithms. Volve field dataset was made public by Equinor, which provides raw data availability for the development of drilling and completion datasets.
In this paper, we utilize the time-based drilling data from the Volve drilling platform and transform it into time series datasets for stuck pipe prediction. Specifically, we introduce our concepts and principles for data development, the rules for selecting time intervals and attributes, the challenges encountered during the data development process and the methods for overcoming them. We discuss the applicability of these methods, the issues they bring, and their impact on data quality. Furthermore, we provide a well development case that includes complex data. The results indicated that our research shows promise in providing time series reference datasets for the application of machine learning algorithms in stuck pipe prediction.
We aim to provide a reference methodology for the development of raw data, reducing barriers to data utilization. We hope to provide data availability, possibly even serving as a reference benchmark dataset for the further applications of machine learning algorithms in the oil and gas sector. Our datasets are made publicly available on GitHub : https://github.com/promiseeee/Time-series-stuck-pipe-prediction.