bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparing fatigue and ultimate loads of two- and three-bladed 20 MW floating offshore wind turbines
Authors: Anstock Fabian , Ulrich Drechsel Klaus , Schorbach Vera 
Published: November 2024

Abstract
Two-bladed turbines could reduce costs in the whole turbine’s life cycle. Yet, the wind loads are less well distributed, and the rotor does not have the calm inertia of a rotating plate, like a three-bladed turbine. This paper should serve as a numerical basis to understand how different loads of large 20MW floating two- and three-bladed turbines actually are to enable a better estimation of implications from these loads. The most surprising finding is that the tower base bending loads do not increase for the floating two-bladed turbine compared to the floating three-bladed reference. The main tower excitation, known as the blade-passing frequency, happens two- instead of three times per revolution for a two-bladed turbine. For bottom-fixed turbines, an operation with the tower eigenfrequency close to this excitation causes severe loads, which is more likely for a two-bladed turbine. For most floating turbines, the tower eigenfrequency is much higher and happens to be in a bandwidth that serves two-bladed turbines better than three-bladed ones. However, it was also observed that the issue of tower resonance might, in general, be less critical for floating turbines due to a vast increase in tower damping. The highest increase in loads has been found at the tower top if no load alleviation concept, e.g. a teetering hinge or free-yaw, is utilized. Yaw and main bearing loads did not show any significant increase. The unique parked T-position exhibited a major benefit in storm conditions. The final results indicate that large floating two-bladed wind turbines may offer a valuable economic advantage when compared to three-bladed turbines of equal design maturity.
Applying triple collocation for verifying wind resource measurements and reanalysis data
Authors: Gottschall Julia , Moskal Angela 
Published: November 2024

Abstract
Dual comparisons or dual collocation, respectively, is a standard approach in wind data analysis, and particularly in the wind energy resource assessment context, for comparing and relating two time series from different sources describing the same quantity as e.g. the wind speed at a specific height over a certain period of time. This comparison can be used to validate a data source, or to derive a correction for one of the two datasets. Though being widely used, dual collocation comes with inherent flaws which are partly unknown or ignored. A major problem is that dual collocation requires the definition of a reference in advance. Triple collocation may instead allow for a more objective and comprehensive evaluation, where (three) suitable data sources are available, and possibly help to identify which datasets are most suited to represent the relevant wind resource. In this study, we apply the triple collocation methodology to two typical wind resource assessment test cases. Results are promising in providing more information on the analysed datasets and improving the use of different types of data for wind resource assessment in the future.
Hyperbox method: a design-oriented selection of fatigue load cases for offshore wind turbines
Authors: Pineau H. , Antonutti R. , Martin A. , Guinot F. 
Published: November 2024

Abstract
In offshore wind engineering, efficient and well-targeted environmental condition sampling is key to strike the best compromise between accuracy in load assessment and number of simulations. This is even more challenging for floating offshore wind, because of the increased sensitivity to environmental directionality and wind-wave misalignments compared to fixed-bottom. For the fatigue analysis, the selection of the Design Load Cases (DLCs) for a mastered design process should both capture the synthetic information from large amount of data and remain representative of the environment, considering insights from system responses. Since standards do not provide a detailed approach to achieve the representativity goal, a fatigue DLC selection method answering the above challenges is thus proposed, based on direct exploitation of environmental wind and wave long-term time series. It proceeds through a sequence of iterative binning steps to define an appropriate set of boxes in hyperspace, here called hyperboxes, i.e. discrete multidimensional bins in the environment’s descriptive parametric space. Representative metrics for each variable within the boxes can be either defined from conventional statistical indicators or determined as a function of the expected system fatigue responses. It ultimately produces a compact and representative fatigue DLC list for the integrated load analysis (ILA) task, accounting for system response sensitivities where relevant. Selection performance is assessed against the original distribution for a set of discretization choices, depending on the offshore wind turbine design characteristics. Project-wise, this method is flexible and adjustable for all design phases, allowing to make the most of a few tens up to several thousands of DLCs. Floating and fixed-bottom offshore wind system design iterations benefit from the presented approach from concept to detailed phases, increasing the efficiency of the engineering team and the chances of project success.
Sensor concepts for gear damage detection in wind power drives
Authors: Merkle L , Binanzer L , Häderle P , Dazer M 
Published: November 2024

Abstract
Gearbox failure in offshore wind turbines can be caused by fatigue damages like tooth fank fracture (TFF) or pitting damage. For damage detection in current applications, simple threshold values for vibration amplitudes are used to initiate a shutdown of the wind turbine. At this time significant damage to the gear is already present and an external maintenance is inevitable. The objective of this experimental study is to determine a better sensor concept for detection of gear damage in wind power drives during operation. The damage needs to be detected at a very early stage before the health condition of the gears becomes critical. Evaluation criteria for comparison of sensor concepts include the earliest possible detection of damage, robust and reliable detection under varying operating conditions, as well as practicality and cost-effectiveness. The test results show, vibration measurement in radial direction and in high frequency ranges is most suitable and most robust for pitting detection during operation. With the best sensor concept in place, it is possible to detect gear damage like pitting at a very early stage of 0.3 % pitting size.
Innovative Benchmarking of Offshore Wind O&M Strategies via AIS Data Analysis
Authors: Baumgärtner David , Kaczenski Jonas 
Published: November 2024

Abstract
By analyzing AIS data, this study provides independent insights into the diverse logistic concepts deployed by wind farm operators. The benchmarking framework developed herein facilitates the evaluation of logistic efficiency, resilience, and sustainability, thereby contributing to the identification of best practices in offshore wind operations and maintenance (O&M) logistics.
The methodology encompasses data collection, preprocessing, and analysis phases. By providing a transparent and data-driven mechanism for benchmarking offshore wind O&M logistics, this study aids in the identification of inefficiencies and the formulation of strategies to enhance logistic operations.
The results indicate significant variations in logistic efficiency across different offshore wind farms (OWF), suggesting that the adoption of best practices could lead to substantial improvements.
An analysis of floating wind turbine towing operations using OpenFAST
Authors: Ramachandran R. C. , Serraris JJ , de Ridder EJ , Desmond C. , Murphy J. 
Published: November 2024

Abstract
The floating wind industry is slowly entering the commercialisation phase and array-scale floating wind farms are imminent. Irrespective of the type of floater used, towing operations represent a crucial marine activity required during installation, major repairs and decommissioning phases. Numerical analysis of towing operations is vital for predicting hydrodynamic motions and towing loads, enabling the identification of metocean limits crucial for achieving optimised safe and efficient execution. This paper presents a unique approach to utilise OpenFAST for the examination of towing operations. Compared to other numerical analysis tools available in the market, OpenFAST stands out as a free, open-source tool specifically designed for wind turbine analysis. The study introduces and evaluates an analytical method using OpenFAST, demonstrating its efficacy in modelling towing dynamics, predicting forces and assessing motion responses of a semi-submersible floating wind turbine in varying wave conditions. The numerical simulations are compared against the results from an experimental campaign. The capability of the method in simulating towing dynamics and the prediction of motion responses are discussed.
Assessing the influence of nonlinear mooring restoring forces in the optimization and design of FOWT
Authors: Amaral Giovanni A. , Mas-Soler Jordi , Simos Alexandre N. 
Published: November 2024

Abstract
The design of mooring systems plays a pivotal role in the success of Floating Offshore Wind Turbine (FOWT) projects. This process naturally involves iterations, as design and analysis are intricately linked. Despite the inherent nonlinearity of mooring system restoring forces, many designers opt for employing an equivalent linear mooring system stifness matrix to expedite the optimization process in early design stages. This article aims to underscore the limitations associated with relying on the equivalent linear model when compared to accounting for nonlinear restoring forces during optimization processes. To illustrate this point, a case study was conducted using the reference semi-submersible platform VolturnUS-S. The study considered intermediate to large water depths and addressed three different mooring confgurations: catenary, semi-taut, and taut lines. The analysis focused on several critical aspects, including ofset watch circles, line tensions (including those at the anchors), and a cost estimate based on the different models. The findings indicate that, for catenary-based mooring systems, the linear model remains a good approximation, leading to no significant loss of accuracy in the context of early design stages. As the lines become tauter, however, the nonlinearities become more pronounced and the errors involved in the linear model can reach unacceptable levels.
Modeling of rain-induced erosion of wind turbine blades within an offshore wind cluster
Authors: Binsbergen Diederik van , Verma Amrit , Nejad Amir , Helsen Jan 
Published: November 2024

Abstract
This study investigates the influence of wind turbine wakes on the incubation period of leading-edge erosion in offshore environments within an offshore wind cluster. The analysis is performed on a cluster of 250MW+ offshore wind farms mainly consisting of wind turbines with over 5MW rated power. The incubation time of the leading-edge erosion is determined for each turbine from wind-and-rain statistics, coating properties, and tuned analytical wake models. The wind speed, wind direction, and conditional probability of the rain are determined using 25 years of ERA5 reanalysis data. Droplet size distributions are derived from Best’s analytical distribution, which provides a probability distribution of the rain droplet size for a given rainfall intensity. For each wind turbine, the inflow speed and rotor speed are calculated using the TurboGaussian wake model. In addition, an analytical surface fatigue model is used to estimate the short-term erosion damage rates. By multiplying the short-term erosion damage rate with their respective join probabilities, equivalent damage is obtained the inverse of which will indicate the coating lifetime. The results indicate that variability in the coating lifetime across the wind farms can reach up to 35%. Notably, turbines that are predominantly positioned upstream are found to have the shortest coating lifetimes.
Data-driven modeling of low-frequency hydrodynamic loads
Authors: Stamenov D , Abbiati G , Sauder T 
Published: November 2024

Abstract
This paper presents a data-driven approach for estimating the linear and quadratic transfer functions relating incoming waves to hydrodynamic loads on floaters. The procedure relies on constructing a nonlinear auto-regressive (NARX) surrogate model for forecasting the hydrodynamic loads and a harmonic probing algorithm for extracting the transfer functions of the system. The implemented harmonic probing method is of numerical nature and avoids the use of computationally expensive symbolic coding tools. The method was verified against synthetic data generated from a potential-flow-based numerical model of the INO WINDMOOR 12 MW floater. The main advantage of NARX models is the fexibility of their structure, meaning that they do not presuppose that the nonlinearity of the hydrodynamic load is quadratic, as it is commonly done.
Infrared thermal measurement in power system considering complex circumstances
Authors: Hao Fangzhou , Wang Shaohua , Ling Ying , Zeng Qi 
Published: November 2024

Abstract
Infrared thermal measurement is a vital tool in power systems for monitoring the temperature of electrical equipment without direct contact. This non-invasive technique helps detect hot spots, identify potential issues, and evaluate the performance of power system components. However, the accuracy of the thermal measurement for power system equipment suffers from complex situations and stochastic circumstances. This paper uses a machine-learning-based method to calculate the accurate surface temperature of equipment, which is mainly based on the feedforward network and backpropagation algorithm. At the same time, multiple regression algorithms are implemented and compared. The simulation results and the experiments show that the infrared thermal measurement based on the proposed method reduces the measurement error to 0.1%.
Analysis of heating performance of transverse magnetic inductor at different operating frequencies
Authors: Peng Yonglong , Wang Yiyang , Li Yabin , Wang Yuanhao 
Published: November 2024

Abstract
Traditional induction heating technology has problems such as uneven temperature distribution and the need to improve heating efficiency and accuracy. Horizontal magnetic flux induction heating technology is a new type of induction heating technology with the advantages of energy efficiency, environmental friendliness, and suitability for local workpiece heating. It is widely used in metallurgy, mechanical manufacturing, light chemical industry, and other fields, holding important economic value. This article studies the heating performance of transverse magnetic inductors at different operating frequencies, simplifies the heating process calculation using finite element analysis, selects stainless steel 405 as the heating material, and sets commonly used parameters such as conductivity and magnetic permeability as fixed values, with frequency as the control variable. Using SolidWorks software to establish a model and COMSOL Multiphysics for simulation, simulated three frequencies: 500Hz, 1kHz, and 5kHz. Analyzed the section temperature, current density distribution, and heating efficiency.
A study on the reduction of high-temperature in the high-pressure piping system of civil aircraft
Authors: Xuan Liming , Jiang Liangliang , Liu Jingxuan 
Published: November 2024

Abstract
For the study of the bleed air flow process in high-pressure pipelines, theoretical analysis and numerical simulation were used to investigate the temperature drop problem in the pipelines. The effect of bleed air and ambient temperatures on the performance of temperature drop in high-pressure pipelines was discussed in detail. The performance of pipeline insulation before and after applying the insulation layer was also discussed. The results show that the higher bleed air temperature and lower ambient temperature obviously cause a greater drop in the bleed air temperature drop. The entrance section of the pipeline is approximately five times the l/d range. Applying the insulation layer can effectively reduce the drop in pipeline temperature. Generally, the air insulation layer can reduce the temperature drop of high-pressure pipeline gas by 25%. If further reduction is required, the vacuum insulation layer can be applied.
A remote monitoring method for gateway electric energy meters based on electric energy, voltage and current conservation decomposition
Authors: Wang Chunyu , Liu Jia , Li Helong , Lu Da , Chen Hao 
Published: November 2024

Abstract
A remote monitoring technique for gateway electricity meters is introduced that leverages conservation principles of electric energy, voltage, and current. It aims to tackle issues related to errors in electric energy meters and transformers that are challenging to distinguish, as well as the high costs associated with on-site testing. The ridge regression is used to solve the formulas for bus power and current conservation to obtain gateway metering points’ error and current loops’ error. The voltage loop error is determined through an averaging method, which is then used to calculate the error in electric energy meters. The voltage consistency method is used to synchronize the time bias between gateway electricity meters, ensuring accurate calculations. The analysis results indicate that the proposed method effectively monitors the operating status of gateway electric energy meters and offers greater accuracy compared to benchmarks. This method can timely discover suspected inaccurate electricity meters, aiding in their maintenance and efficient operation.
Introduction to cross-arm T pole tower of 110kV transmission line and design verification of double circuit T pole tower
Authors: Li Chu , Gong Shijie 
Published: November 2024

Abstract
With the development of various fields in China, users have higher and higher requirements for power reliability. In order to improve the reliability of 110 kV transmission lines, a new type of cross-arm T-connection technology came into being. This paper introduces the characteristics of the original T-connection technology and the new T-connection mode of the new T-connection technology, as well as the design verification of the double-circuit T-connection tower, and draws the conclusion that the new T-connection tower model is reasonable and the force of the rod can be effectively configured.
A biomacromolecular additive based on pullulan polysaccharide to enhance the life of lead-acid battery packs in DC systems
Authors: Meng Xuanren , Wang Xiaoming , Lin Xiangyu , Dou Qian 
Published: November 2024

Abstract
With the rapid growth in demand for mobile power, lead-acid batteries still occupy a large market share due to their excellence in energy storage. However, their lifespan is affected by various factors, which limits the application efficiency and environmental friendliness. In this regard, this paper proposes a method to enhance the service life of lead-acid battery packs by applying biomacromolecule additives. A lead-acid battery pack modification method is investigated by introducing chitosan, a natural macromolecule with excellent electrical conductivity and biodegradation properties, into lead-acid batteries. So that the chitosan-modified material forms a stable and protective film on the surface of the battery electrode plate, thereby reducing the analysis of sulphate crystals on the electrode surface. The method of modification of lead-acid battery packs has been studied. Comparative analysis of the experimental data shows that the modified battery pack exhibits lower charge transfer impedance and better electrochemical stability than the traditional lead-acid battery during the cyclic charge/discharge test. Through the cycle charge/discharge test, the energy loss of the battery with biomolecules is 30% lower than that of the unmodified battery, and the number of charge/discharge cycles increases by 60%, which effectively prolongs the service life of the lead-acid battery. The progress of this paper not only has guiding significance for the performance improvement of traditional lead-acid batteries but also provides a significant theoretical and experimental basis for the development and application of environmental friendly battery materials.
Research on control strategy of electric vehicle thermal management system motor
Authors: Liu Chunhui 
Published: November 2024

Abstract
The low efficiency and difficulty in low-temperature heating are the challenges currently faced by the thermal management system of new energy vehicles. A multi-heat source vehicle thermal management system for waste heat cascade recovery and utilization was proposed, and the performance of the vehicle thermal management system was studied through a combination of component testing and one-dimensional simulation. Based on a one-dimensional simulation model, the characteristics of the motor waste heat source are analyzed. The increase in the inlet water temperature of the motor coolant will lead to enhanced heat dissipation of the motor to the air, resulting in a waste of motor waste heat. Based on the results of the analysis, an energy cascade management strategy is constructed. The optimal heating mode is selected by collecting temperature signals such as motors, and the cut-off valve is controlled through logic gates to achieve flexible switching of different modes. The system effectively reduces the energy consumption of thermal management systems, which is of great significance for developing thermal management systems for new energy vehicles.
An energy management method for combined load forecasting of fuel cell ships
Authors: Jiang Jundao , Zou Liang , Liu Xingdou , Pang Shuo , Zhang Li 
Published: November 2024

Abstract
The article proposes an energy management method (EMM) for fuel cell ships, which consists of two parts: load forecasting (LF) and real-time optimized scheduling (RTOS). LF is composed of Long Short-Term Memory neural networks, which are capable of being trained to predict future loads based on historical ship load information. RTOS consists of model predictive control and can allocate energy in real time. Initially, shiploads and battery status are collected in real time, and then LF passes the predicted load sequence to RTOS. RTOS optimizes real-time energy allocation based on the predicted load and the current operating status of two sets of batteries, while meeting system constraints and maintaining the battery SOC at a healthy level, to minimize operational cost consumption. The simulations demonstrate that the EMM can consistently maintain SOC at a healthy level and reduce fuel cell ship operating costs to some extent, thereby improving economic efficiency.
Introduction
Authors: Ballesteros Bernardo 
Published: November 2024

AbstractThe Introduction situates the main themes addressed in the book and outlines the limits of the study. It begins by contextualizing the book’s perspective on the question of early Greek indebtedness to Near Eastern poetry (§1). Next, it justifies a working definition of divine assemblies which is both flexible and minimalistic. They are poetic situations where a group of gods is portrayed together (§2). The sources’ oral and written dimensions have implications: early Greek and Babylonian poems can be studied as performance poetry, and divine assemblies as traditional typical scenes (§3). Approaches to the gods in relation to literature and religion are also introduced. Divine assemblies enhance comparative understanding of early Greek and Babylonian religious thought as expressed in poetry and myth (§4). Finally, the structure of the book is outlined: Part I is devoted to poetic technique and cross-cultural transmission, Part II to narrative theology and divine power (§5).