bluuebunny/crossref_metadata_2025_split huggingface dataset:
Life Cycle Environmental Impact of Wind Turbines: What are the Possible Improvement Pathways?
Authors: Guilloré A , Canet H , Bottasso CL 
Published: June 2022

Abstract
This study explores the effect of different technology choices on the life cycle Greenhouse Gases (GHG) emissions of wind turbines. It aims at identifying possible improvement pathways and quantifying potential benefits. First, an automated Life Cycle Assessment (LCA) model is developed and validated against other studies. The breakdown of the resulting Impact Of Energy (IOE) by life stages, components and materials is presented for a selected reference turbine. Sensitivity analyses are conducted on the different hypotheses to model the turbine life cycle. The model is then applied to analyze the potential effect of turbine size, foundation type, tower type, drivetrain technology, carbon-fiber blades and thermoplastic polymer resin for the blades. The tower type (especially wooden tower) and the thermoplastics (allowing to recover materials at the end-of-life) are identified to have the biggest potential to reduce the life cycle environmental impact of wind energy.
Case study on the benefits and risks of green hydrogen production co-location at offshore wind farms
Authors: He Wei , Zheng Yi , You Shi , Strbac Goran , Therkildsen Kasper T. , Olsen Gudmund P. , Howie Aaron , Byklum Eirik , Sharifabadi Kamran T. 
Published: June 2022

Abstract
Abstract Advances in large-scale green hydrogen production (LGHP) create commercial opportunities for enhancing rapid offshore wind farm (OWF) development. This study investigates whether LGHP co-location at OWF sites improves those OWF’s economic outlooks under potential electrical grid capacity bottlenecks towards 2050. Eight cases have been studied using measured annual OWF power production series and cost estimation integrated with offshore engineering experience: i) two base cases: 2 GW OWFs with HVAC and HVDC transmission infrastructure showing that the levelized cost of electricity (LCOE) increases, and ii) six LGHP co-location cases demonstrating that the calculated levelized cost of hydrogen (LCOH) reduces when the LGHP capacity increases from 20% to 50%, and 100% of 2 GW. Furthermore, three economic improvement factors studied are: i) utilizing existing gas pipelines reducing LCOH by 7.5%, ii) hydrogen for offshore customers changing “no-go” projects to “go”, and iii) scaling-up from 2 to 4 GW reduced the LCOH by 17%. This study shows that LGHP co-location is effective at maintaining OWF full production, but has higher risks including i) LGHP co-location safety at OWFs, ii) high costs to cover more operational conditions and iii) running LGHP operations using high, fluctuating OWF power. Further R&D of LGHP co-location are recommended.
A comparison of wind turbine blade parametrization schemes for planform design optimization
Authors: Iori Jenna , McWilliam Michael K. 
Published: June 2022

Abstract
This work compares nodal, spline and interpolation parametrization schemes for wind turbine blade planform design. The comparison is done on a power coefficient maximization problem, where the aerodynamic properties of the blade are computed using the Blade Element Method. The problem is solved using a gradient-based interior-point method with analytic gradients. We show the variation in planform design for each parametrization scheme when the degrees of freedom of the parametrization varies. We compare how the power coefficient converges with increasing degrees of freedom for each scheme. Our results shows that the B´ezier spline, the Piecewise Cubic Hermite Interpolation Polynomial (PCHIP) and Lagrange interpolation schemes present the best grid convergence out of all studied schemes.
An open-source framework for the uncertainty quantification of aeroelastic wind turbine simulation tools
Authors: Verdonck H , Hach O , Polman J D , Braun O , Balzani C , Müller S , Rieke J 
Published: June 2022

Abstract
The uncertainty quantification of aeroelastic wind turbine simulations is an active research topic. This paper presents a dedicated, open-source framework for this purpose. The framework is built around the uncertainpy package, likewise available as open source. Uncertainty quantification is done with a non-intrusive, global and variance-based surrogate model, using PCE (i.e., polynomial chaos expansion). Two methods to handle the uncertain parameter distribution along the blades are presented. The framework is demonstrated on the basis of an aeroelastic stability analysis. A sensitivity analysis is performed on the influence of the flapwise, edgewise and torsional stiffness of the blades on the damping of the most critical mode for both a Bladed linearization and a Bladed time domain simulation. The sensitivities of both models are in excellent agreement and the PCE surrogate models are shown to be accurate approximations of the true models.
Comparison of a mid-fidelity free vortex wake method to a high-fidelity actuator line model large eddy simulation for wind turbine wake simulations
Authors: Houck D R , deVelder N , Kelley C L 
Published: June 2022

Abstract
The need for mid-fidelity wind turbine simulations is increasing due to their balance of accuracy and computational efficiency. A common form of mid-fidelity code is the free wake vortex method (FVWM), but these are known to inaccurately represent the far-wake depending on their implementation. Herein, we compare CACTUS, a FVWM code, to Nalu-Wind, an actuator line model large eddy simulation (ALM-LES) code with particular focus on the far wake. Specifically, we compare one CACTUS simulation, which necessarily has steady and uniform inflow, to three Nalu-Wind simulations using a steady and uniform inflow, a low turbulence inflow, and a high turbulence inflow. The comparison reveals interesting parallels between CACTUS and all Nalu-Wind cases, but ultimately demonstrates that CACTUS is not an appropriate tool for the simulation of the far-wake of a wind turbine.
Employing Bayesian Quadrature to Improve Fitting of Surrogate Models to Wind Turbine Loads
Authors: Caterina Clark Anna , Clark Caitlyn E. 
Published: June 2022

Abstract
Stochastic, high-fidelity simulations are increasingly used to estimate wind turbine and plant loads and performance. While these simulations are more accurate, they are prohibitively computationally expensive. Surrogate models can be used to replace direct simulation for lower computational cost; for stochastic surfaces, a Gaussian Process (GP) is appropriate for random variables that follow Gaussian distributions, such as turbine loads and performance.
In this study, we employ an advanced surrogate modeling technique to estimate the loads, reliability, and energy production of wind turbines in a wind plant, based on mid-fidelity aero-elastic simulations. Specifically, we use Bayesian Quadrature (BQ) to produce a training data set that, for a given size, minimizes the variance over the entire domain of a GP surrogate model to estimate rotor torque load on a waked turbine. When applied to a GP that was trained with aero-elastic simulation data, the BQ-enabled algorithm reduced variance—a measure of predictive uncertainty—over the entire GP to < 0.3 with 30 samples. When compared to a uniform sampling approach with the same solution space, the BQ method reduces computational time by 99.88%, or over 590 simulation evaluations.
Assessment of a heterogeneous computing CFD code in wind farm simulations
Authors: López B , Guggeri A , Draper M , Usera G 
Published: June 2022

Abstract
The use of heterogeneous architectures, based on CPU-GPU processors, has led to a significant increase in the performance of parallel computing applications. In recent years, this approach has been implemented in various computational fluid dynamics (CFD) codes to take advantage of the compute capability of the GPU graphics cards. The objective of this work is to assess the performance of a general purpose CFD open-source code in wind energy applications, running in a heterogeneous architecture. To this aim, a numerical wind turbine model was migrated from a CPU-based Fortran program to the CFD code. Several timing tests were performed on a local computing station, while running simulations of well-documented wind tunnel experiments. The results obtained show a significant reduction in computational time and resource required, indicating a great potential of the GPU-accelerated CFD code to be used in large wind farms simulations or in real-time applications.
Towards the development of an advanced wind turbine rotor design tool integrating full CFD and FEM
Authors: Cozzi Lorenzo , Bellucci Juri , Giovannini Matteo , Papi Francesco , Bianchini Alessandro 
Published: June 2022

Abstract
Large, highly flexible wind turbines of the new generation will make designers face un-precedent challenges, mainly connected to their huge dimensions. To tackle these challenges, it is commonly acknowledged that design tools must evolve in the direction of both improving their accuracy and turning into holistic, multiphysics tools. Furthermore, the wind turbine industry is reaching a high level of maturity, and ever more accurate and reliable design tools are required to further optimise these machines. Within this framework, the study shows the development of an integrated platform for blade design integrating 3D CFD flow simulations and 3D-FEM structural analysis. Artificial intelligence techniques are applied to develop an optimization procedure based on the proposed tool. The potential of the new platform has been tested on the well-known test case of the MEXICO rotor, for which an optimization of the blade design has been carried out. Exploring a design space sampled with 2000 CFD and FEM computations, increases in blade torque have been obtained at each of the three tip-speed ratios (TSR) investigated, ranging from 6% at the nominal TSR to 14% at the lowest one, while stresses on the blade are kept almost unaltered.
Multidisciplinary aeroelastic optimization of a 10MW-scale wind turbine rotor targeting to reduced LCoE
Authors: Serafeim G. , Manolas D. , Riziotis V. , Chaviaropoulos P. 
Published: June 2022

Abstract
In the present paper, multidisciplinary optimization (MDAO) is applied with the aim to reduce the levelized cost of energy (LCoE) of the DTU-10MW Reference Wind Turbine (RWT) rotor. As application paradigm, the widely applied in the literature passive load control method of Bend Twist Coupling (BTC) is considered. The integrated optimization framework combines in a common loop, rotor aerodynamic and full wind turbine structural elasto-dynamic analyses, aiming at determining the optimum rotor diameter, the planform of the blade in terms of twist and chord distributions, the offset ply angle for BTC and the inner structure of the blade with cost function directly the LCoE. It is based on an in-house servo-aero-elastic analysis tool for determining the ultimate loads along the span of the blades and the power yield, whereas a cross-sectional analysis tool is employed for acquiring structural properties of the modified blade and stresses distributions over the blade sections. A cost model of the overall wind turbine is implemented by combining existing in the literature models and open data. The new rotor design is found to have a reduced LCoE by 0.71% and to produce 2.4% higher energy annually due to its increased by 3.7% diameter.
Unsteady aerodynamic modelling for dual-rotor wind turbines with lifting surface method and free wake model
Authors: Chen Jiajia , Yin Fanfu , Li Xinkai , Ye Zhaoliang , Tang Wei , Shen Xin , Guo Xiaojiang 
Published: June 2022

Abstract
A time-marching aerodynamic model for dual-rotor wind turbines (DRWT) is presented with the lifting surface method and free wake model. The performance of a reference DRWT by two axial connected NREL 5MW wind turbines is calculated to verify the algorithm. The output converges with remarkable oscillation. Free wakes swell under the coupling effect. The accumulated power of DRWT outranges single-rotor wind turbine (SRWT) by a limited extent under certain operating conditions. The front rotor (FR) produces the major portion of the power, especially for low inflow velocity. The unsteadiness of performance and spanwise load is further investigated, and the result shows that the power output of the rear rotor (RR) undergoes greater fluctuation than FR. The rotor-rotor induction strengthens both the rotors’ performance before they align and weakens it when they rotate away. The additional disturbance caused by FR’s tip vortices acts negatively on RR’s torque by upwashing the blade tip.
Experimental proof-of-concept of an energy ship propelled by a Flettner rotor
Authors: Elie B , Bognet B , Boileau T , Weber M , Gilloteaux J-C , Babarit A 
Published: June 2022

Abstract
The energy ship is a new concept for offshore wind energy capture. It consists of a wind-propelled ship that generates electricity using water turbines attached underneath its hull. Since it is not grid-connected, the generated energy is stored aboard the ship (for instance, using batteries or through conversion to hydrogen using an electrolyser). This concept has received little attention until today. In this paper, a proof-of-concept of an energy ship propelled by a Flettner rotor is presented. The experimental results are compared to numerical simulations. A very good agreement is obtained, which validates previous numerical simulations that indicate that a full-scale energy ship equipped with Flettner rotors can lead to positive net energy production.
Multi-Timescale Wind-Based Hybrid Energy Systems
Authors: Stanley Andrew P. J. , King Jennifer , Barker Aaron , Guittet Darice , Hamilton William , Bay Christopher , Fleming Paul , Sinner Michael 
Published: June 2022

Abstract
This paper focuses on the design of wind-based hybrid power plants that operate at different timescales ranging from seconds to days. Traditionally, renewable power plants have been designed to maximize the amount of energy produced. As the energy system transitions to higher amounts of renewables, hybrid power plants may be asked to provide baseload or peaking plant services that have been traditionally been serviced by coal and natural gas power plants. This paper demonstrates that considering these types of plants and their corresponding objects, that operate at different timescales, result in different solutions and should be considered in the design phase of hybrid power plant development.
Optimal Planning of Co-Located Wind Energy and Hydrogen Plants: A Techno-Economic Analysis
Authors: Li Honglin , Rahman Jubeyer , Zhang Jie 
Published: June 2022

Abstract
Green hydrogen produced using renewable electricity could play an important role in a clean energy future. This paper seeks to analyze the techno-economic performance of integrated wind and hydrogen systems under different conditions. A co-located wind and hydrogen hybrid system is optimized to reduce the total system cost. We have adopted and improved a state-of-the-art techno-economic tool REopt, developed by the National Renewable Energy Laboratory (NREL), for optimal planning of the integrate energy system (IES). In addition to wind and electrolyzer components, we have also considered battery energy storage, hydrogen tank, and hydrogen fuel cell in the IES. The results show that (i) adding electrolyzers to the grid-connected wind energy system could reduce the total system cost by approximately 8.9%, and (ii) adding electrolyzers, hydrogen tank, and hydrogen fuel cells could reduce the total system cost by approximately 30%.
Atmospheric Irrigation with Wind Turbines
Authors: Jauch C , Emeis S 
Published: June 2022

Abstract
In this paper, atmospheric irrigation with wind turbines is proposed. This technology addresses the problem of water scarcity by enhancing the natural water circuit in the atmosphere with wind turbines. There are three different operating modes conceivable for this technology. In two of these the wind turbines interact with the ground in their near wake. The third operating mode is the one which is discussed in this paper, and it aims at transporting water potentially over long distances. The basic working principle, the utilized physical phenomena and the basic design of the technology are introduced. The equations governing the hydraulic and the hydrological effects are presented. The goal of this paper is to quantify the necessary power and the necessary amount of water when wind turbines humidify a certain volume of air in the atmosphere. For this purpose, the power and water demand are assessed, both in a generalized manner and for a realistic scenario. It is concluded that the proposed system can achieve the objective in most wind speed conditions. However, the required amount of water is substantial. Therefore, an alternative source of fresh water has to be found when the system is used on a comparably large scale.
The emergence of supersonic flow on wind turbines
Authors: De Tavernier Delphine , Terzi Dominic von 
Published: June 2022

Abstract
The future generation of wind turbines will be characterised by longer and more flexible blades. These large wind turbines are facing higher Reynolds numbers, as a consequence of longer chord lengths and increased relative wind speeds. Higher tip speeds, however, also result in an increased Mach number. Although the maximum tip speed in steady design conditions may remain (well) below the critical value, the presence of turbulence, wind gusts, blade deflections, etc. in combination with the flow acceleration over the airfoil surface, may cause a significant increase in the velocity perceived over the blade surface. We have evaluated the operational conditions of the IEA 15MW reference turbine using OpenFAST in normal design and off-design conditions to demonstrate that, if unabated, near-future wind turbines will be at risk of suffering from local supersonic flow. The driving factor is identified to be inflow turbulence, however, the tip airfoil is also of major importance. Local supersonic flow conditions may lead to severe lifetime degradation.
Aeroelastic modelling of tail fins for small wind turbines
Authors: Hammam Mohamed M , Wood David H 
Published: June 2022

Abstract
Many small upwind turbines use a tail fin to align the rotor with the wind. Despite the importance of a well-designed fin for efficient operation and in generating ultimate and fatigue loads, the aeroelastic modelling of tail fins is not well developed. This work extends the previous linearized analyses by including nonlinear effects and the difference between the yaw angle and the angle of attack. The analysis is based on unsteady slender body theory, but includes the vortex lift generated at high angles of attack and the effects of vortex bursting. The model predicts with reasonable accuracy the yaw behaviour of delta-shaped tail fins (without a rotor) released at 45° in a wind tunnel, provided allowance is made for the viscous friction in the yaw bearings. The difference in the response frequency between the linear and nonlinear model increases at the higher yaw angle of 80° for which no wind tunnel measurements are available. As a first step towards simplifying the nonlinear model, the difference in yaw angle predictions from the linear model is estimated. The maximum difference is a function of initial yaw angle and is large for yaw angles of magnitude greater than 45°.
Design Guidelines for Deployable Wind Turbines for Defense and Disaster Response Missions
Authors: Naughton B , Houchens B , Summerville B , Jimenez T , Preus R , Reen D , Gentle J , Lang E 
Published: June 2022

Abstract
Access to on-site electrical energy is critical to ensuring a successful military or humanitarian response to conflicts and disasters. These missions typically rely on access to liquid fuel that could be vulnerable to disruption or attack during transport. Generating power on location with wind technology—whether at a contingency base or disaster response coordination point—can reduce this risk and enhance mission reach by diversifying energy sources. Common characteristics of these missions are short planning and execution time horizons and a global scope of potential locations. Compared to conventional wind turbine applications, defense and disaster response applications place a premium on rapid shipping and installation, short-duration operation (days to months), and quick teardown upon mission completion. These design drivers depart from features found in conventional distributed wind turbines, thus necessitating unique design guidance. The supporting information for this guidance comes from available relevant references, technical analyses, and input from industry and military stakeholders. This paper serves as a summary of the full report, Design Guidelines for Deployable Wind Turbines for Military Operational Energy Applications (Sandia report SAND2021-14581 R [1]), which presents the best currently available design guidance for deployable wind turbines to facilitate the effective development and acquisition of technology solutions to support mission success.
Effect of tip speed ratio on the aerodynamic noise of a small wind turbine: An optimization study
Authors: Pourrajabian Abolfazl , Dehghan Maziar , Rahgozar Saeed , Wood David 
Published: June 2022

Abstract
A dual-objective optimization study was carried out to illuminate how the tip speed ratio of a small wind turbine affects the aerodynamic noise as well as the blade geometry. A 0.75 kW three-bladed small horizontal axis wind turbine was selected as the case study. Two important goals were considered in the study: maximization of the output power and the minimization of the aerodynamic noise. The former was calculated by the well-known blade-element momentum theory while a validated semi-empirical model was adopted for the computation of the latter. A combination of these goals defined the objective function and the weighted-sum approach was employed to find the optimal values for the design variables of the optimization including the distributions of the chord and the twist angle along the blade together with the tip speed ratio. The extracted power was calculated at the rated wind speed of 10 m/s while the noise was computed at lower wind speeds of 5 and 7.5 m/s. The genetic algorithm technique was adopted for the muti-objective optimization. The results revealed the importance of the blade tip region in producing the emitted aerodynamic noise. Specifically, an increase in the chord and twist values near the tip results in the reduction in the emitted noise. Results also show that a good compromise between the two goals is achievable such that a noticeable reduction in the emitted aerodynamic noise is attainable in exchange for a very small drop in the power coefficient. The optimization results also indicated that the noise could be adequately reduced at the smaller value of the tip speed ratio without a large reduction in output power which is due to the decrease in the rotational speed of the turbine.