bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupling simulation of the cooling air duct and the battery pack in battery energy storage systems
Authors: Zhu Xinlong , Xu Xintian , Kong Benben , Wang Junyi , Shi Hong , Jiang Yanlong
Published: May 2023

The air-cooled battery thermal management system (BTMS) is a safe and cost-effective system to control the operating temperature of the battery energy storage system (BESS) within a desirable range. Different from the design of the air supply flow field of most BESSs in previous studies, this study proposes a novel calculation method that combines the cooling air duct and the battery pack to enhance the heat dissipation of the battery. Using computational fluid dynamics (CFD) models, potential problems with numerical calculations of cooling air duct and battery packs alone and coupled simulations of the two are investigated. The important factors influencing the uniformity of air supply are identified, and creative measures for improvement are proposed. The results in this paper show that the uniformity of the outlet air supply does not indicate that the temperature uniformity performance of the matrix battery meets the requirements due to the variation of the sub air duct outlet pressure, and the coupling simulation of the cooling air duct and the battery pack is an essential process for BESS. With the improvements proposed in this paper, the standard deviation coefficient of velocity is reduced from 60.3% to 12.6%. Furthermore, the innovative improvement of placing the partition in the connecting duct can regulates the battery temperature between 298.58 K and 311.73 K and ensures a maximum temperature difference of only 4.22 K for a single battery. Ultimately, the power consumption of the cooling system can be reduced by 6.9%. The results of the paper provide a guide for uniform heat dissipation in BESS.
Lyman-α polarization from cosmological ionization fronts. Part II. Implications for intensity mapping
Authors: Koivu Emily , Long Heyang , Yang Yuanyuan , Hirata Christopher M.
Published: May 2023

This is the second paper in a series whose aim is to predict the power spectrum of intensity and polarized intensity from cosmic reionization fronts. After building the analytic models for intensity and polarized intensity calculations in paper I, here we apply these models to simulations of reionization. We construct a geometric model for identifying front boundaries, calculate the intensity and polarized intensity for each front, and compute a power spectrum of these results. This method was applied to different simulation sizes and resolutions, so we ensure that our results are convergent.
We find that the power spectrum of fluctuations at z = 8 in a bin of width Δz = 0.5 (λ/Δλ = 18) is Δℓ ≡ [ℓ(ℓ + 1)C
ℓ/2π]1/2 is 3.2 × 10-11 erg s-1 cm-2 sr-1 for the intensity I, 7.6 × 10-13 erg s-1 cm-2 sr-1 for the E-mode polarization, and 5.8 × 10-13 erg s-1 cm-2 sr-1 for the B-mode polarization at ℓ = 1.5 × 104.
After computing the power spectrum, we compare results to detectable scales and discuss implications for observing this signal based on a proposed experiment. We find that, while fundamental physics does not exclude this kind of mapping from being attainable, an experiment would need to be highly ambitious and require significant advances to make mapping Lyman-α polarization from cosmic reionization fronts a feasible goal.
Bootstrapping multi-field inflation: non-Gaussianities from light scalars revisited
Authors: Wang Dong-Gang , Pimentel Guilherme L. , Achúcarro Ana
Published: May 2023

Primordial non-Gaussianities from multi-field inflation are a leading target for cosmological observations, because of the possible large correlations generated between long and short distances.
These signatures are captured by the local shape of the scalar bispectrum. In this paper, we revisit the nonlinearities of the conversion process from additional light scalars into curvature perturbations during inflation.
We provide analytic templates for correlation functions valid at any kinematical configuration, using the cosmological bootstrap as a main computational tool. Our results include the possibility of large breaking of boost symmetry, in the form of small speeds of sound for both the inflaton and the mediators.
We consider correlators coming from the tree-level exchange of a massless scalar field.
By introducing a late-time cutoff, we identify that the symmetry constraints on the correlators are modified. This leads to anomalous conformal Ward identities, and consequently the bootstrap differential equations acquire a source term that depends on this cutoff.
The solutions to the differential equations are scalar seed functions that incorporate these late-time growth effects.
Applying weight-shifting operators to auxiliary “seed” functions, we obtain a systematic classification of shapes of non-Gaussianity coming from massless exchange.
For theories with de Sitter symmetry, we compare the resulting shapes with the ones obtained via the δN formalism, identifying missing contributions away from the squeezed limit. For boost-breaking scenarios, we derive a novel class of shape functions with phenomenologically distinct features in scale-invariant theories.
Specifically, the new shape provides a simple extension of equilateral non-Gaussianity: the signal peaks at a geometric configuration controlled by the ratio of the sound speeds of the mediator and the inflaton.
Pressure-driven membrane inflation through nanopores on the cell wall
Authors: Zhong Qi , Wu Chen-Xu , Ma Rui
Published: May 2023

Walled cells, such as in plants and fungi, compose an important part of the model systems in biology. The cell wall primarily prevents the cell from over-expansion when exposed to water, and is a porous material distributed with nanosized pores on it. In this paper, we study the deformation of a membrane patch by an osmotic pressure through a nanopore on the cell wall. We find that there exists a critical pore size or a critical pressure beyond which the membrane cannot stand against the pressure and would inflate out through the pore and further expand. The critical pore size scales linearly with the membrane tension and quadratically with the spontaneous curvature. The critical pressure is inversely proportional to the pore radius. Our results also show that the fluid membrane expansion by pressure is mechanically different from the solid balloon expansion, and predict that the bending rigidity of the membrane in walled cells should be much larger than that of the mammalian cells so as to prevent membrane inflation through the pores on the cell wall.
Creation mechanism of electron–positron pair on equally spaced multiple localized fields
Authors: Li Chuan-Ke , Lin Nan-Sheng , Zhou Xian-Xian , Jiang Miao , Li Ying-Jun
Published: May 2023

We investigate the electron–positron creation process from multiple equally spaced distributed oscillating electric fields. The computational quantum field theory (CQFT) is applied to analyze the effect of the number of local fields, the distance between them, and their potential height on the created particle number. It is found that whether adjacent electric fields overlap plays an important role. The creation rate exhibits a direct linear relationship with the number of fields when they do not overlap, but exceeds the sum of the rate when the fields alone. They exhibit a distinctly nonlinear relationship when they overlap, and in particular exhibit a quadratic relationship when the fields completely overlap. These phenomena corroborate that the particle pair creation in the interaction region is non-uniform and influenced by the strength of the central strongest electric field.
Single crystal growth and electronic structure of Rh-doped Sr3Ir2O7
Authors: Wang Bingqian , Peng Shuting , Ou Zhipeng , Wang Yuchen , Waqas Muhammad , Luo Yang , Wei Zhiyuan , Huai Linwei , Shen Jianchang , Miao Yu , Sun Xiupeng , Yin Yuewei , He Junfeng
Published: May 2023

Ruddlesden-Popper iridate Sr3Ir2O7 is a spin–orbit coupled Mott insulator. Hole doped Sr3Ir2O7 provides an ideal platform to study the exotic quantum phenomena that occur near the metal–insulator transition (MIT) region. Rh substitution of Ir is an effective method to induce hole doping into Sr3Ir2O7. However, the highest doping level reported in Sr3(Ir1−x
Rh
x
)2O7 single crystals was only around 3%, which is far from the MIT region. In this paper, we report the successful growth of single crystals of Sr3(Ir1−x
Rh
x
)2O7 with a doping level of ~ 9%. The samples have been fully characterized, demonstrating the high quality of the single crystals. Transport measurements have been carried out, confirming the tendency of MIT in these samples. The electronic structure has also been examined by angle-resolved photoemission spectroscopy (ARPES) measurements. Our results establish a platform to investigate the heavily hole doped Sr3Ir2O7 compound, which also provide new insights into the MIT with hole doping in this material system.
Transition state performance optimization of propfan engine based on DDPG algorithm
Authors: Zheng Hua , Yang Zhao-xing , Wang Ya-fan , Zhao Dong-zhu
Published: May 2023

As the “heart” of an aircraft, aero-engines work in harsh environments of high temperature and high pressure for a long time. In order to ensure that the engine can operate safely and reliably within the entire flight envelope, a large safety margin needs to be reserved in the design of the control system. This design idea limits the full play of the engine performance, so it is necessary to carry out the research on the performance search control (PSC) of aero-engine. This paper studies the performance optimization control of propfan engine based on deep reinforcement learning algorithm. The Deep Deterministic Policy Gradient (DDPG) algorithm, which is more suitable for continuous action space, is used to optimize the acceleration process of the propfan engine. The simulation results show that, compared with the unoptimized adjustment process, the transition state adjustment time of the engine is reduced by 32.5% under the action of the optimal adjustment law obtained by the DDPG algorithm. Therefore, the DDPG algorithm can be applied to the performance optimization of the engine acceleration process, and has a good transition state performance optimization effect.
Study on conjugate heat transfer characteristics of flexible structure of solid motor nozzle based on multiple working conditions
Authors: Wang Shengxiong , Li Yingkun , Xu Jinsheng
Published: May 2023

In order to study the influence of the deformations of the nozzle’s flexible sections on its inner wall’s heat transfer, this research uses the two-dimensional axisymmetric model and the k − ω SST turbulence model to numerically analyze the tail flow field of the flexible-extendible nozzle under multiple working conditions. The flow field and the inner wall’s heat transfer of the flexible sections with and without deformations are simulated and analyzed. The simulation results show that when the flexible sections are deformed, new shock waves will be generated in the tail flow field of the nozzle; the temperature and the heat flux of the first half of each flexible section decrease, while those at the end of each flexible section increase, and the deformations’ effect on temperature and heat flux diminishes over time. The research shows that the deformations of the flexible sections will make the inner wall’s heat transfer of the flexible sections uneven, and the inner wall’s ablation at the end of each flexible section may be aggravated, while that of the front half may be alleviated.
Effect of leading-edge parameters of multi-element airfoil on aerodynamic characteristic
Authors: Cai Jinyang , Luo Jiaming
Published: May 2023

Studying the effect of leading-edge parameters of 30P30N on aerodynamic characteristic was carried out. Effect of changing the gap and overlap of the slat of the airfoil were mainly investigated. Numerical simulation was applied to obtain aerodynamic characteristics, results show that: the lift coefficient in the linear segment basically does not change with the gap, the drag coefficient decreases with change of the gap. The overlap and gap of slat have obvious effect on the lift-to-drag ratio. The smaller the gap between slat and fixed wing, the greater the lift-to-drag ratio is achieved. With the increase of overlap between slat and fixed wing, lift to drag ratio increases.
A universal and simple method to solve the velocity / acceleration of parallel mechanism
Authors: Wang Rui , Guo Xiangyu , Zhong Shisheng , Ge Yuhao , Zhang Faqian
Published: May 2023

The velocity/ acceleration analysis is an important part of the kinematic analysis, which is of great significance to establish a universal and simple velocity / acceleration analysis model to realize the precise control of parallel mechanism. In this paper, according to the differential relationship among position, velocity and acceleration, the velocity / acceleration mapping formula between the driving branch and the position and attitude parameters of the moving platform is established. Moreover, in order to ensure the accuracy of calculation, the characteristic value correction iteration method is used to solve the singular and ill-conditioned of Jacobian matrix and Hessian matrix which may be generate under some special attitudes. The principle of the method is universal and easy to understand, moreover, the experiments show that the method can realize the velocity / acceleration solution of hybrid drive mechanism.
Numerical simulation of the effect of different impeller structural parameters on the lift and thrust of a new impeller thruster
Authors: Chen H , Wang S , Wang Z X , Wang X Y , Qiu Z Z
Published: May 2023

The Half-Rotating impeller thruster(HRIT) based on the Half-Rotating Mechanism is a new type of impeller thruster. Its impeller motion principle is different from the fixed impeller of the ordinary impeller thruster. In order to obtain better aerodynamic force in working, it is necessary to explore the HRIT in different structural parameters. The influence of the radius of the rotating arm, the width of the blade is calculated and analyzed in detail by numerical calculation method. The calculation results show that the radius of the rotating arm is the main factor affecting the lift and thrust of the HRIT. The aerodynamic characteristics of the thruster under different blade widths are also different. The aerodynamic characteristics of the thruster under different blade widths are also different, the lift reaches its peak value when blade widths d=30mm, and the thrust reaches its peak value when d=35mm; The blade lengths also has a great influence on the aerodynamic force of the thruster, and the lift and thrust both increase with the increase of blade lengths. At the same time, compared with the fixed impeller thruster, the HRIT has relatively balanced aerodynamic performance.
Dynamics Research and Analysis of landing on the surface of Asteroid
Authors: Chen Danhe , Li Chuangyi , Su Zhou
Published: May 2023

Asteroid detection has been the main research field of deep space exploration, and even in the future years. Countries have carried out missions to flyby and landing on the surface of asteroids, the sampling can help human explore the origins of small bodies, as well as origin of the solar system. While the particular environmental factors such as small size and low gravity of asteroids make the landing more difficult, this paper designs a four-legged inverted triangle soft lander, supplemented by thrust reversers and rope anchors for stable landing. A mathematical model of the lander landing on the surface of target asteroid is established, and the motion and dynamic response of lander in different landing modes is studied, conditions and safe landing range is well defined. Results of the analysis have demonstrated the effectiveness of dynamic landing model for the proposed lander.
Finite element dynamic modeling and attitude control for a slender flexible spacecraft
Authors: Huang Wenke , Li Linfeng , Dong Wenye , He Liwen , Feng Taoming , Xiao Jun
Published: May 2023

This paper aims to study the dynamic modeling and attitude control of a kind of slender flexible spacecraft. The basic structure of this kind of spacecraft is different from the traditional structure of a center rigid body with flexible appendages, but rigid bodies at both ends, which are connected by a flexible truss structure. Firstly, the finite element modeling method is adopted to establish the dynamic model of this kind of spacecraft, and the vibration frequency and damping of the flexible structure are obtained. The unconstrained modes of the flexible spacecraft are obtained through mathematical analysis, finite element analysis and frequency domain analysis. In addition, a nonlinear sliding surface with angular velocity constraint is designed. On this basis, an adaptive sliding mode (ASM) controller is proposed, stability of the close-loop system under the controller is proved, and the dynamic model is verified through mathematical simulation.
Optimal trajectory planning technology for the cooperative flight of unmanned aerial vehicles
Authors: Feng Kai , Nan Ying
Published: May 2023

In the face of a complex battlefield environment, a multi-dimensional dynamic planning algorithm is proposed to solve the trajectory planning problem of the cooperative flight mission process of unmanned aerial vehicles. Under the constraints of aircraft kinematics, the collision between aircraft and space-time cooperation, and under the influence of random wind field, threat area, and other interference factors, the algorithm can make the UAV group pass through the mission points as much as possible, and at the same time, smooth the track points to make the trajectory reach the optimal solution. Finally, the simulation results of the program written in C++ and MATLAB show that the algorithm can meet the global optimization, and can calculate in real-time and online. It has strong engineering application value.
Research on modelling analysis and design method of helicopter operation requirements based on MBSE
Authors: Sun L , Gao F , L L Q , Lou B C
Published: May 2023

Helicopters are characterized by complex missions, high risk, high cost, high reliability and long lead times. In order to adapt to the more complex operational requirements in the future, the thesis addresses the problems of long iterative cycles, low efficiency and model duality in the traditional helicopter operation requirements analysis process, the theory of model-based systems engineering (MBSE) is introduced into operation requirements analysis for helicopter. A modelling analysis and design method for helicopter operation requirements analysis is proposed based on MBSE. The overall framework for helicopter operation requirements analysis based on the model is designed. On this basis, a modelling design method and key implementation process of requirements analysis is established, which provides theoretical and technical support for the positive design of helicopter operation requirements demonstration.
Attitude control of a moving mass-actuated fixed-wing UAV based on LADRC
Authors: Zheng Jingzhong , Selezneva Maria Sergeevna , Yi Jianfeng , Zhu Liangliang
Published: May 2023

This paper concerns attitude control of a moving mass-actuated fixed-wing unmanned aerial vehicle (MFUAV). Unlike conventional roll motion of UAV, which is controlled by ailerons, this MFUAV uses the movement of mass block inside the wing to generate roll moment. It is difficult to design a suitable attitude controller for it due to the strong non-linearity and coupling of the MFUAV dynamics. Linear active disturbance rejection control (LADRC) proved to be a simple and effective alternative to conventional PID control. LADRC is able to eliminate disturbances with the help of extended state observer (ESO) and does not depend on the accurate mathematical models of particular systems. Finally, simulation results show that the attitude tracking control of MFUAV is well achieved with robustness. This shows that the designed method is easy to adapt and implement during the actual flight of the MFUAV.
Optimized relative phase maintenance for heterogeneous area-to-mass ratio microsatellite constellations
Authors: Liu Siyang , Meng Tao , Jin Zhonghe
Published: May 2023

Long-term maintenance missions present a challenge for low-orbit heterogeneous area-to-mass ratio (AMR) microsatellite constellations due to inconsistent fuel consumption and carrying capacity. Based on the idea of cooperative control, the fuel consumption of fuel-rich satellites is properly increased in this paper to assist fuel-starved satellites in saving fuel, so as to optimize the fuel consumption balance of each satellite and extend the controllable lifetime of the constellation. The evolution of the relative phase under J2
and atmospheric drag perturbation is analyzed. The target configuration and the strategy of maintenance are modeled and optimized based on the principle of fuel consumption balance. The traditional absolute phase maintenance method for heterogeneous AMR constellation is devised. On this basis, the orbit altitude is optimized with the simulated annealing algorithm to improve the fuel consumption balance. Based on the relative phase maintenance method, the maintenance strategy is optimized with the genetic algorithm to further reduce fuel and enhance the fuel consumption balance. Finally, the three methods are contrasted.
Integrated flutter test of a horizontal-tail model in the large-scale continuous transonic wind tunnel
Authors: Han Jiangxu , Liu Nan , Huang Yanxin , Yang Ximing , Wang Song
Published: May 2023

Wind tunnel test is a critical way to investigate flutter characteristics of aircraft, particularly in identifying the transonic dip phenomenon in the aeroelastic design. The continuous wind tunnel has advantages over the blow-down wind tunnel in long running time, wide bandwidth of dynamic pressure, and stable flow field. Thus, the continuous wind tunnel is more suitable for transonic flutter tests. Flutter test techniques are studied for FL-62 wind tunnel, the first large-scale continuous transonic wind tunnel in China. A protection system and a real-time signal processing are developed to ensure the safety and efficiency. Flutter boundaries of a horizontal-tail model are investigated in FL-62 wind tunnel in the Mach number regime between 0.65 and 0.98. In the test, structural vibrations are measured via strain gauges, deformations and pressure distributions are measured via non-contact optical techniques, and flutter boundaries are predicted via a modal identification method.
Experiment research on instantaneous characteristics of variable-thrust hybrid rocket motor by reconstruction techniques
Authors: Wei Tianfang , Cai Guobiao , Tan Guang
Published: May 2023

The firing test of variable-thrust Hybrid Rocket Motor (HRM), operated with Hydrogen Peroxide (HP) and Polyethylene (PE), based on closed-loop thrust control, has been carried out in this paper. The experiment research on instantaneous characteristics of HRM is conducted based on reconstruction techniques. A post-processing software has been developed to reconstruct the instantaneous performance parameters during the burning stage of HRM. Meanwhile, the formula of regression rate is fitted by reconstruction results through a single firing test, which is a significant advantage compared with traditional method. The averages of instantaneous parameters calculated by reconstruction techniques accord well with experimental data summarized by traditional consumption weight loss method, and the accuracy of reconstruction calculation is better than 1%. This paper is designed to achieve the reconstruction for instantaneous parameters and research the instantaneous characteristics during the variable-thrust firing test of HRM. The reconstruction techniques have the better accuracy, and also provide a critical method for the research on instantaneous characteristics of hybrid rocket motor.
Parameter sensitivity analysis under failure condition of lifting device mechanism
Authors: Feng Yunwen , He Zhiyu , Li Shuai , Xue Xiaofeng , Cao Mingyue
Published: May 2023

The sensitivity of each influencing parameter in the selected range of the complex multi-hinge space flap mechanism under typical fault conditions is studied, and the influence degree of each parameter and its dispersion on the driving torque of the mechanism is determined. Firstly, the rigid-flexible coupling dynamic model of the mechanism is established considering the flap deformation, and then the influence of four parameters that may cause mechanism failures, such as hinge friction, aerodynamic load, driving speed and assembly error, on the driving torque of the mechanism is explored. Then, the drive torque of the mechanism under each parameter value is given, finally, the sensitivity of each selected parameter is obtained by the direct de rivation method. The results show that the parameters are positively correlated with the driving torque, the aerodynamic load coefficient and hinge friction parameters are the most sensitive to the driving performance of the mechanism, while the driving speed is the smallest. After the aerodynamic load increased by 30%, the maximum driving torque of the inner mechanism increased by 28.8%; when the hinge friction parameter was in the range of 0~0.05, the maximum torque of the inner and outer mechanisms increased by 8.6% and 8.4% respectively. In engineering applications, the lubrication of each spherical hinge should be increased, the driving speed should be reduced, and the manufacturing and assembly accuracy should be improved.To a certain extent, it can prevent failures and improve the reliability of the flap mechanism.
Review on vibration test and fault analysis of rv reducer
Authors: Xuan Liang , Hong WenXiong , Wan ZeFu , Lin Zhuang
Published: May 2023

As the core component of industrial robot RV reducer, its health condition determines the life and accuracy of the robot. The main reason that restricts the long-term stable operation of industrial robots. This paper analyzes and compares the advantages and disadvantages of various technologies from three aspects: state detection, signal processing and fault diagnosis. The problems of developing real-time online evaluation are also discussed. Deep data mining and exploring new methods of RV reducer condition monitoring are the research difficulties in this field. It provides a reference for further research in the field of RV reducer.
Influence of panel oscillation on the shock flow field in isolator under complex background wave system
Authors: Wang Tiexiang , Li Yingkun , Zhu Min , Zhou Changsheng
Published: May 2023

In this paper, a self-developed solver is used to numerically simulate the isolator section under complex inlet conditions, and the influence of forced panel vibration on the shock flow field in the isolator under complex inlet conditions is investigated. The results show that the forced vibration of the panel has a certain influence on the shock flow field in the isolator under complex inlet conditions.
Pattern mining based data fusion for wind turbine condition monitoring
Authors: Chesterman Xavier , Verstraeten Timothy , Daems Pieter-Jan , Nowé Ann , Helsen Jan
Published: May 2023

The profitability of wind turbine energy production is for an important part determined by the operation and maintenance costs of wind turbines. An important driver of these costs is currently the premature failure of components due to excessive wear. If it would be possible to accurately predict these failures, preventive maintenance can be made more effective, which should result in less downtime and expensive unexpected failures. This in turn should lower the operational and maintenance costs. The research presented here is a contribution to the research on condition monitoring and failure prediction for wind turbines. To this end, a methodology for failure prediction is designed that combines (fuses) multiple information sources (i.e. SCADA and status log data). The novelty of this research lies in the fact that pattern mining techniques are used to identify relevant rules for a rule-based failure classifier. The methodology is validated on generator bearing failure cases from a real operational wind farm. The results show that the methodology is able to predict generator bearing failures accurately well in advance. The rules on which the predictions are based are interpretable and correspond in general to expert knowledge on the matter.
Social acceptance “in my backyard” - What drives social acceptance of renewable energy projects?
Authors: San Martin O
Published: May 2023

This paper aims to present a general overview of the social acceptance of wind energy developments in Europe and identify influential social acceptance factors. First, we show social acceptance levels for renewable energy (onshore wind) projects in selected European countries and how it varies across and within countries. In addition, we produce regional maps showing within country variations in social acceptance indicators. Second, using an econometric model, we study how different factors influence social acceptance levels. Our investigation assesses social acceptance of renewable energy developments using primary data from two comprehensive opinion surveys. The first opinion survey-conducted in September/October 2021-contains more than 16 000 observations from 8 European countries and allows us to assess how social acceptance is affected by the distance to the wind parks. The second opinion survey – conducted in June 2022 - contains more than 18 000 observations from 9 European countries and allows us to assess-through an econometric model how social acceptance is affected by a set of relevant influential factors, including perceptions, preferences towards energy suppliers, preferences for community benefits schemes, and demographic factors among others. The analysis of the information gathered for this investigation shows variations across European countries and within each of the countries covered by this study. The findings from this study might be helpful to take into consideration during the planning and development of renewable energy projects and improve targeting the work towards community engagement aiming to obtain the social license to build and operate renewable energy projects.
New insights into the influence of turbines on the behaviour of migrant birds: implications for predicting impacts of offshore wind developments on wildlife
Authors: Robinson Willmott J , Forcey G , Vukovich M
Published: May 2023

Knowledge of the movement and behaviour of birds and bats around turbines in the offshore marine environment is critical for assessing the environmental impacts of offshore wind developments in the eastern USA. To address the problem of gathering high-quality, long-term data on these species in this remote environment, we designed a multi-sensor system that was recently deployed for 6 months in 2021 and 2022. Two Acoustic and Thermographic Offshore Monitoring (ATOM™) systems were deployed on wind turbines 23 nautical miles off the coast of Virginia, USA. The systems were operational during the day and night and recorded 1,581 detections of birds and bats, with 99% of detections occurring in the fall. Most detections were of birds, including 5 shorebird species, 3 gull species, 1 tern species, 3 raptor species, 1 woodpecker species, and 18 passerine species. Skuas, corvids, and swallows were also observed. There were 521 detections of bats. Differences between species detected and identified in each sensor confirms that a multi-sensor approach for monitoring is beneficial. There were no observed collisions; two individuals (1 bird and 1 bat) suffered air displacement, causing them to fall, but they recovered and continued flying. ATOM also collected novel data on insects, tracking over 7,000 insects around the turbine rotor swept zone and revealed foraging behaviour in 596 of the 1,581 bird and bat detections. Offshore wind turbines thus provide potential sites for perching and foraging. Although these turbine sites provide a new opportunity to feed, which may be beneficial for insectivores and omnivores in enabling them to reach migration destinations in better condition, the consequences of a potentially delayed arrival are unknown (positive, negative, or neutral). Overall, our approach produced the first detailed insights into terrestrial land bird and bat activity around offshore turbines, providing novel information on changes in behaviour when turbine blades are moving and during higher wind speeds. Moreover, our data show that foraging activity appears to be conducted with an awareness of the moving blades and in safe zones close but parallel to blade movements. We recorded 113 observations of activity within 10 m of the moving blades and 70 observations where interactions with moving turbine blades were within 1 m; we call these latter avoidance measures nanoavoidance. No collisions were observed.
Sustainable end-of-life value chain scenarios for wind turbine blades
Authors: Fayyaz S , Lund K W , Khoshnevisan B , Madsen E S , Birkved M
Published: May 2023

This study presents a sustainable end-of-life (EoL) value chain scenario assessment framework for decommissioned wind turbine blades (WTBs) to address the challenge of increased volumes of WTBs reaching their EoL. Findings from the previous studies highlight that WTBs EoL scenarios and their upscaling are yet to be addressed environmentally and economically. The scenarios investigated herein are mechanical shredding, pyrolysis, and cement co-processing that can be industrially upscaled. Together with the industrial partners, end-of-life scenario value chains are identified, to assess their sustainability through material flow analysis (MFA), life cycle assessment (LCA), and techno-economic assessment (TEA). A prospective consequential LCA model is proposed for scenarios with different technology readiness levels (TRL) expected to be commercialized at different timeframes. IPCC’s Shared Socio-economic Pathways (SSPs) will be used to describe foreground and background systems in 2030, 2040, and 2050. More specifically, SSP1 (i.e., green road), SSP2 (i.e., middle road), and SSP5 (i.e., fossil-fueled development) will be employed and quantified based on integrated assessment models (IAM). Furthermore, environmental impacts, economic criteria, Social sustainability, and circularity cannot directly be compared to evaluate the scenarios. Thus, this research proposes multi-criteria decision-making (MCDM) method to evaluate the three end-of-life scenario value chains considering a prospective scheme and addressing the key challenges related to the assessment of emerging technologies. Furthermore, a full conceptual framework of the methodology is presented.
Assessment of turbulence intensity estimates from floating lidar systems
Authors: Kelberlau Felix , Neshaug Vegar , Venu Anish
Published: May 2023

In the pre-construction phase of offshore wind energy projects floating lidar systems (FLS) are used for wind site assessment. Their measurements of mean wind speed and direction have proven to be accurate according to existing standards. But for the assessment of turbulence intensity (TI), a widely-accepted procedure and acceptance criteria are missing. This study investigates different evaluation methods, namely linear regression analysis and the key performance indicators (KPIs) presented by the Consortium for Advancing Remote Sensing (CFARS). The assessment is based on data from an offshore trial of the Fugro SEAWATCH Wind Lidar Buoy (SWLB) against the meteorological mast and a collocated fixed profiling wind lidar at Blyth, UK. The results show that the accuracy of TI estimates from FLS can be evaluated well, when the KPIs mean bias error (MBE) and representative TI error suggested by CFARS are used. We propose best-practice acceptance thresholds of ±1% for MBE and ±1.5% for the representative TI error. The motion-compensation approach of the SWLB works well and after compensation, its TI data are similar to the data from the fixed reference lidar. The impact of lidar-specific effects is minor in the analyzed data set and near-to-zero biases are found for all measurement elevations and wind speed bins in comparison to mast data.
Analysis of the systematic errors of energy yield assessment in the context of wind farm repowering
Authors: Mazoyer P , Duc T , Bechmann A , Kariniotakis G
Published: May 2023

The repowering of wind farms is a rapidly developing area of research and is expected to represent 40 GW of wind projects by 2030 in the European Union. This has led to the emergence of energy yield assessment methods that incorporate operational data from existing farms with the aim of surpassing traditional methods that rely solely on physical modelling and onsite measurements. The current literature on repowering relies upon the assumption that learning from operational farm data applies to the future farm. Indeed, calibration and adjustment methods assume that physics-driven models (PDMs) have spatially and temporally correlated errors. This study investigates this assumption by analysing PDM errors for 25 pairs of nearby wind projects. A statistically significant correlation is observed. We discuss whether it is reasonable to utilise operational data from existing farms, which possess different characteristics, to improve the long-term production prediction of a repowered farm.
Wind fields from atmospheric turbulence measurements
Authors: Friedrich Jan , Peinke Joachim
Published: May 2023

We present recent advances in the modeling of wind fields and their reconstruction from real-world atmospheric turbulence measurements. The proposed wind field model provides a statistically coherent framework for modeling the empirically observed occurrence of extreme atmospheric events. Furthermore, we demonstrate that the model is general enough to enmesh real-world measurement points, e.g., from meteorological masts or LIDAR, and thus provides a rather convenient method for the reconstruction of highly resolved, three-dimensional wind fields. Our methodology is based on the so-called superstatistics of Gaussian-distributed (or Mann-type) velocity fields with fluctuating covariances and exactly reproduces higher-order statistics due to extreme small-scale wind fluctuations. Therefore, it could lead to more realistic inflow conditions and might potentially enhance the current design standard of wind turbines. We further discuss potential applications of the wind field model in the context of LIDAR measurements as well as for wake situations.
Data-driven characterization of performance trends in ageing wind turbines
Authors: Murgia Alessandro , Cabral Henrique , Tsiporkova Elena , Astolfi Davide , Terzi Ludovico
Published: May 2023

The precise quantification of wind turbine long- and short-term performance is crucial to assess the health state of ageing turbines and to evaluate the benefit of maintenance activities. Indeed, during its lifetime, wind turbines can experience a decay in terms of performance (e.g. due to wear) or improvement (e.g. due to technology optimizations). For this reason, we developed an integrated data-driven methodology to characterize the long- and short-term performance trends and performance variability in turbines. The methodology is validated on a synthetic dataset with imposed decay and then tested on a real wind farm operated by Engie Italy and composed of seven turbines for which ten years of SCADA data are collected. We show how this methodology accurately captures the evolution of a turbine’s performance and how it is capable of quantifying the impact of the controller update.
Effect of wind speed distribution and site assessment on pitch bearing loads and life
Authors: Rezaei Ashkan , Nejad Amir R.
Published: May 2023

In this paper, the wind speed distribution at thirteen onshore and offshore wind sites has been studied. Different probability distributions are used to estimate the wind speed distribution. Several goodness-of-fit indicators were used to assess the suitability of the fitting. The highest results were achieved by Kernel distribution in both onshore and offshore wind sites. Onshore wind sites did not fit well compared to offshore wind sites. Rayleigh distribution results at onshore wind sites were worse than at offshore wind sites. Onshore and offshore wind distributions result in various load duration distributions in pitch bearing. The concept of life ratio was introduced to compare the long-term fatigue life of the pitch bearing in different wind speed conditions. It is observed that the fatigue life of the pitch bearings in some wind sites is less than that of related IEC classes, and the risk of failure of the pitch bearing before the end of its expected designed fatigue life exists.
Geomorphological mapping and landform characterization of Semeru volcano after the eruption in 2021
Authors: Bachri S , Fathoni M N , Sumarmi  , Masruroh H , Wibowo N A , Khusna N , Billah E N , Yudha L
Published: May 2023

The eruption of the Semeru volcano in 2021 has diverse impacts on the landscape and surroundings. It is essential to detect recent landscape features to promptly evacuate personnel and property near the volcano and take emergency treatment measures in case of sudden danger. This study presents a detailed geomorphological map on a 1:50.000 scale for the Semeru volcano after the eruption in 2021. The analysis of the hybrid approach and the on-screen image interpretation (OSII) method on DEM data, optical satellites, and lithology units was carried out to obtain morphological, morphochronological, and morphoarrangement information. While, morphoprocess information was obtained through field observations. We used DAS Rejali for our study area. The results of identifying geomorphological conditions divide the Rejali watershed area into 32 landforms consisting of landform units from volcanic, structural, fluvial, and marine processes. Twenty-three land units in the research location are landforms from volcanic processes. This condition causes morphological conditions, material availability, and processes that dominantly reflect the characteristics of an active volcano. In addition, the landform units from the fluvial process in the Rejali watershed area were identified as many as six units in the form of floodplains of lahar flows along the main river. Landforms with structural genesis were placed in Mandalika formation and diorite rock breakthrough. The structural formation in the Rejali watershed has retention and rock structures that are not easily eroded by water. It becomes a bottleneck formation as a barrier between the upstream and middle areas
Rural waste management model in creating an inclusive economy
Authors: Rahmawati Emma , Mujianto  , Amir Azhar , Sukarno Taufan Daniarta , Suprapedi
Published: May 2023

Waste is a common problem faced in various regions, a lot of waste has not been handled especially in the rural areas. The percentage of waste generated in villages is higher than in the urban areas, mostly due to the larger number of residents in villages. But behind the waste problem, there is an economic opportunity if the village can manage it well. Currently, there are villages that have succeeded in managing their waste that can realize an inclusive economy inside their villages. Therefore, the purpose of this research is to develop a village waste management model in implementing an inclusive economy. This research method used descriptive qualitative data collection through in-depth interviews, FGD’s and observation. The results showed that the village waste management model includes a management team, processing plan, technology, financing, utilization and collaboration. This village waste management model involves various parties and the participation of village communities inclusively proven to reduce poverty and stunting in the village.
Measuring opportunities: Transforming Indonesia’s economy through utilizing natural resources for sustainable development through green economy indicators
Authors: Anggraeni V , Achsanta A F , Purnomowati N H
Published: May 2023

Many countries with low to medium incomes need a long time to recover from the economic downturn caused by Covid-19. The impact of Covid-19 affects the main development priorities in Indonesia, such as poverty alleviation, the achievement of sustainable development, and the transformation of the green economy. The economic and fiscal constraints facing Indonesia need attention, and the Indonesian economy needs to establish policy criteria. The purpose of this article is to analyze the environmental problems in Indonesia and then identify the government policy related to sustainable development programs to release them. The Ministry of Finance has an essential role in the SDGs by allocating National Budget to environmental programs. Sustainable development is Indonesia’s commitment to the international community to reduce the use of carbon emissions to promote a green economy. The green economy indicators that we elaborate in supporting SDGs programs are low-carbon development, resource efficiency, and socially inclusive.
Mapping the Semeru lahar-flood hazard of Supiturang Village using the analytical hierarchy process (AHP) method
Authors: Irawan L Y , Prasetyo W E , Wahyu H Z P , Devy M M R , Yusuf A M , Hartono R , Purwanto
Published: May 2023

Supiturang is one of the villages in Kecamatan Pronojiwo, Kabupaten Lumajang that sits on the lahar flow path of Semeru Volcano. The village constantly faces a lahar-flood hazard, inevitably impacting the local community. Therefore, this paper aims to map the lahar-flood hazard of Supiturang village using the analytical hierarchy process (AHP) method. The main parameters are 1) slope (%), 2) distance from drainage (m), 3) elevation (m ASL), 4) rainfall (mm), and 5) land cover (water body/bare land/forest/grassland/plantation/ricefield/mixed agriculture/built-up area). This research is a descriptive-quantitative study that used survey and geographic information system (GIS) approaches. The result showed that the lahar-flood hazard class of Supiturang varies from very low, low, moderate, high, to very high. The very high hazard class is distributed near the lahar flow path. Despite most settlements being in the moderate hazard class, some are in the high and very high hazard class. The findings from this research can advantage the further improvement and development of evacuation routes, assembly points, refuges, observatory stations, and other related Semeru Volcano disaster risk mitigation actions.
Effect urban development on urban heat island in Depok Subdistrict, Sleman Regency, Yogyakarta
Authors: Irawati D , Noviani R , Rindarjono M G
Published: May 2023

Urban development follows population growth caused by various factors, both natural and non-natural. The increasing number of residents in Depok Subdistrict makes the demand for land also increase. Residential land that continues to develop can cause temperature conditions in Depok Subdistrict to increase or known as Urban Heat Island. This study purpose to determine how the influence of urban development on the Urban Heat Island phenomenon and to analyze the Urban Heat Island and land surface temperatures. This study concludes that there has been an urban heat island in Depok Subdistrict in 2014 with a distribution area of 49% of the total area of Depok Subdistrict and 51% non-UHI with a UHI threshold of 26.18°C. Meanwhile, in 2019 there was a decrease in UHI. to 30% of the total area and 70% are in non-UHI areas with a UHI threshold of 27.18°C. Although there is a decrease in UHI, the surface temperature of the soil has increased from 29.78°C to 31.10°C. In Depok Subdistrict population density does not affect the UHI value but the surface tribe value does affect the UHI index value.