Showing papers on "Turbine blade published in 2019"
119 citations
TL;DR: A comprehensive review of alloying effects in nickel-based single-crystal superalloys for turbine blades and vanes operating in a very aggressive environment of stress, oxidation and corrosion is presented in this paper.
Abstract: A comprehensive review of alloying effects in nickel-based single-crystal superalloys for turbine blades and vanes operating in a very aggressive environment of stress, oxidation and corrosion is p...
116 citations
TL;DR: The environment-friendly energies are wind, solar, wave and marine current power as mentioned in this paper, and the researchers moved to computer simulation from the experimental and numerical analysis in the recent period.
Abstract: The environment-friendly energies are wind, solar, wave and marine current power. In the recent period, the researchers moved to computer simulation from the experimental and numerical analysis. Th...
101 citations
TL;DR: A review of the existing protection solutions is presented in this paper, where a design that can account for the stiffness mismatch between an integrated metallic erosion shield and the blade may then reveal the solution to leading edge erosion.
Abstract: The offshore wind industry's pursuit of greater blade lengths and higher tip speeds, as well as a move to new markets with monsoonal climates, has caused leading edge erosion to progress from an issue that only affects a small number of turbines in the most extreme environments to a major problem that affects entire wind farms. Leading edge erosion results in reduced turbine efficiency that requires expensive repairs and tip speeds to be limited to protect blade edges. A review of the existing protection solutions is presented. The production and application of both gelcoats and flexible coatings relies heavily on manual procedures, leaving the coatings vulnerable to defects that can act as initiation points for erosion. Leading edge tapes are manufactured autonomously in a controlled environment and are consequently relatively free of defects. When applied effectively, the tapes possess very good erosion resistance. However, poor application can result in the formation of air pockets and wrinkles that reduce the adhesion of the bond, resulting in the tape disbonding from the blade. Metallic erosion shields have been shown in accelerated rain erosion tests to possess a lifetime greater than that of an offshore wind turbine blade. However, differences in stiffness between the blade and the metallic shield introduces a risk of the shield detaching under loading and as a result, the reliance on the adhesive is high. Integrating a metallic erosion shield into the blade mould would remove an additional manufacturing process and alleviate any aerodynamic concerns caused by a profile step on the leading edge of the blade. A design that can account for the stiffness mismatch between an integrated metallic erosion shield and the blade may then reveal the solution to leading edge erosion.
91 citations
TL;DR: Based on the increasing number of end-life wind turbine blades and the emphasis on resource conservation and environmental protection, more and more attention has been paid to the recycling and reuse of wind turbines as discussed by the authors.
Abstract: Based on the increasing number of end of life wind turbine blades and the emphasis on resource conservation and environmental protection, more and more attention has been paid to the recycling and ...
81 citations
TL;DR: A penalty approach for coupling adjacent patches that requires only a single, dimensionless penalty coefficient for both displacement and rotation coupling terms, alleviating the problem-dependent nature of the penalty parameters is presented.
76 citations
TL;DR: In this article, a short overview of main repair techniques for wind turbine blades and the related problems of computational mechanics is presented, including the leading edge erosion of wind turbine blade, injection repair and viscous flow, patch/scarf repair as well as curing and adhesive development.
75 citations
TL;DR: In this article, an ice sensor integrated with an ice mitigation system is required to prevent ice formation on wind turbine blades, which can lead to turbine shutdown, power loss and damage to turbine components.
Abstract: The capacity of installed wind power is growing rapidly in cold climate regions; however, turbine blades are susceptible to ice accumulation. The aerodynamic properties of turbine blades are highly sensitive to ice accretion, which can significantly impair aerodynamic performance. Ice accretion on the blades of a wind turbine can lead to turbine shutdown, power loss and damage to turbine components. To prevent ice formation on wind turbine blades, an ice sensor integrated with an ice mitigation system is required. The ice sensor can be used with a de-icer on the blade surface. However, the current ice sensing and de-icing technologies are inefficient and integrated systems need appreciable improvement. This paper reviews ice sensing and active mitigation techniques for a wind turbine blade surface, which are categorized based on several key parameters. Furthermore, this paper investigates the conceptual design of integrating ice sensing and mitigation systems. The advantages and disadvantages of the integrated systems are presented to provide valuable insights on ice prevention for wind turbines operating in ice prone locations.
71 citations
70 citations
TL;DR: In this article, a solution to reduce the metallurgical issues at higher temperatures by using ultra-high temperature ceramics was proposed, where hafnium diboride was selected to examine its feasibility for the fabrication of gas turbine stator blades.
70 citations
TL;DR: The paper proposes a fast and accurate method for the calculation of the constantly changing Angle of Attack (AOA) based on the velocity flow field data at two reference points upstream the turbine blades without the need for extensive post-processing for efficient turbine aerodynamic analysis and optimisation.
TL;DR: In this paper, the authors analyse and compare end-of-life options for wind turbine blade materials (mainly glass fiber reinforced plastic and carbon fibre reinforced plastic) in terms of environmental impact (focusing on energy consumption), using their own data together with results gathered from the literature.
TL;DR: In this article, the authors focused on entropy generation and exergy destruction of condensing steam flow in turbine blade with the roughness and established the governing equations including entropy transport equation combined with condensation model, transition SST model and roughness correlation.
TL;DR: In this article, the authors proposed a systematic scheme combining mechanical recycling and 3D printing to recycle the valuable constituents of the scrap blades and reuse them in a Fused Filament Fabrication (FFF) process with the aim of improving the mechanical performance of 3D printed components.
Abstract: The wind energy industry is one of the fastest-growing application sectors of composites, where reinforcement fibers are used in the manufacturing of light rotor blades. Considering the limited lifetime of turbine blades, a growing number of wind turbines will start to be decommissioned. Turbine blades are generally landfilled at their end-of-life, which highly impacts the environment. This paper proposes a systematic scheme combining mechanical recycling and 3D printing to recycle the valuable constituents of the scrap blades and reuse them in a Fused Filament Fabrication (FFF) process with the aim of improving the mechanical performance of 3D printed components. Mechanical grinding integrated with a double sieving mechanism is utilized to recover the reinforcement fibers. Tensile test specimens with 5 wt% fiber content are fabricated from the recycled fibers and plastic pellets and their mechanical properties as well as internal microstructure are investigated. The results demonstrate an improvement of 16% and 10% in the elastic modulus and ultimate strength of the reinforced composite filament as compared to the commercially available pure PLA filament. As well, a Young's modulus of 3.35 GPa was observed for the FFF fabricated samples, which is an 8% increase relative to pure PLA samples.
TL;DR: In this paper, the aerodynamic performance of NACA 4412 airfoil with sandpaper which was used as an alternative control device instead of vortex generators was investigated, especially considering how the sandpaper affected the growth of the separation bubble.
TL;DR: A novel and economic optical technique based on three-dimensional digital image correlation (3D-DIC) is described for monitoring the health of wind turbine blades and a fault detection method is proposed based on the relative deformation of the turbine blades during operation.
TL;DR: A new paradigm for design and fabrication of wind blades is demonstrated by 4D printing process, which combines several beneficial attributes in one blade that can show reversible bend-twist coupling (BTC) and lead to eco-friendly wind turbines.
TL;DR: In this paper, a hybrid anti-icing strategy that combines minimized electro-heating at the blade leading edge and a superhydro-/ice-phobic coating to cover the blade surface was explored for wind turbine icing mitigation.
TL;DR: In this paper, the effect of natural gas-hydrogen blended fuel on the combustion performance of a Rich/Quench/Lean (RQL) can combustor was investigated, and a reduced GRIMECH 3.0 mechanism was adopted as the reaction scheme of the combustion process.
TL;DR: The main failure modes of turbines are reported, and the existing monitoring techniques for these components, with their own particular advantages and disadvantages, are summarised in this review.
Abstract: The need for non-destructive testing/structural health monitoring (SHM) is becoming increasingly important for gas turbine manufacturers. Incipient cracks have to be detected before catastrophic events occur. With respect to condition-based maintenance, the complex and expensive parts should be used as long as their performance or integrity is not compromised. In this study, the main failure modes of turbines are reported. In particular, we focus on the turbine blades, turbine vanes and the transition ducts of the combustion chambers. The existing monitoring techniques for these components, with their own particular advantages and disadvantages, are summarised in this review. In addition to the vibrational approach, tip timing technology is the most used technique for blade monitoring. Several sensor types are appropriate for the extreme conditions in a gas turbine, but besides tip timing, other technologies are also very promising for future NDT/SHM applications. For static parts, like turbine vanes and the transition ducts of the combustion chambers, different monitoring possibilities are identified and discussed.
TL;DR: In this article, the authors investigate fusion joining of wind turbine blades manufactured using thermoplastic resins, which can reduce cycle times and energy consumption during manufacturing and facilitate end-of-life recycling and on-site manufacturing.
TL;DR: In this article, the main issues for the wind industry in the experimentation with respect to erosion are examined and a review focusing on the rain erosion on the leading edge of the wind turbine blades giving prominence to (1) the rain simulations, (2) experimental erosion facilities, and (3) variables to characterize erosion.
Abstract: Developments in the wind industry reveal intricate engineering challenges, one of them being the erosion on the leading edge of the wind turbine blades. In this review work, the main issues for the wind industry in the experimentation with respect to erosion are examined. After a historical and general overview of erosion, this review focuses on the rain erosion on the leading edge of the wind turbine blades giving prominence to (1) the rain simulations, (2) experimental erosion facilities, and (3) variables to characterise erosion. These three factors have to be improved to establish a research field enabling the prediction of erosion behaviour and providing useful information about how the rainfall affects the leading edge of the wind turbine blades. Moreover, these improvements in the experimentation of the erosion would be a first step to understand and predict the erosion damage of the wind turbine blades. Finally, this review work also will help to cope with experimental investigations and results in the rain erosion on the leading edge with a deeper critical thinking for future researchers.
TL;DR: In this paper, a largeeddy simulation of a laboratory-scale horizontal axis turbine operating over an irregular bathymetry in the form of dunes is performed and the results demonstrate the need for studying in detail the flow and turbulence characteristics at potential tidal turbine deployment sites and to incorporate observed large-scale velocity and pressure fluctuations into the structural design of the turbines.
Abstract: A large-eddy simulation (LES) of a laboratory-scale horizontal axis tidal stream turbine operating over an irregular bathymetry in the form of dunes is performed. The Reynolds number based on the approach velocity and the chord length of the turbine blades is approximately 60,000. The simulated turbine is a 1:30 scale model of a full-scale prototype and both turbines operate at very similar tip-speed ratio of λ ≈ 3. The simulations provide quantitative evidence of the effect of seabed-induced turbulence on the instantaneous performance and structural loadings of the turbine revealing how large-scale, energetic turbulence structures affect turbine performance and bending moments of the rotor blades. The data analysis shows that wake recovery is notably enhanced in comparison to the same turbine operating above a flat-bed and this is due to the higher turbulence levels generated by the dune. The results demonstrate the need for studying in detail the flow and turbulence characteristics at potential tidal turbine deployment sites and to incorporate observed large-scale velocity and pressure fluctuations into the structural design of the turbines.
TL;DR: The experimental results reveal that the proposed method is able to not only adaptively extract valuable fault features from the complex SCADA data, but also obtains higher detection accuracy and generalization capability compared with conventional machine learning models and individual deep learning model.
TL;DR: In this paper, an experimental study was conducted to characterize aerodynamic performance degradation of wind turbine blades induced by dynamic ice accretion process, and the aerodynamic degradation was found to be a strong function of the angle of attack of the blade model with more significant degradations at lower angles of attack.
TL;DR: Computational results demonstrate that the proposed approach can successfully identify both the blade crack locations and crack contours in UAV-taken images.
Abstract: A two-stage approach for precisely detecting wind turbine blade surface cracks via analyzing blade images captured by unmanned aerial vehicles (UAVs) is proposed in this paper. The proposed approach includes two main detection procedures, the crack location and crack contour detection. In locating cracks, a method for extracting crack windows based on extended Haar-like features is introduced. A parallel sliding window method is developed to scan images and the cascading classifier is developed to classify sliding windows into two classes, crack and noncrack. Based on detected windows containing cracks, a novel clustering algorithm, the parallel Jaya K -means algorithm, is developed to assign each pixel in crack windows into crack and noncrack segments. Crack contours are obtained based on boundaries of crack segments. The effectiveness and efficiency of the proposed crack detection approach are validated by executing it on a personal computer and an embedded device with UAV-taken images collected from a commercial wind farm. Computational results demonstrate that the proposed approach can successfully identify both the blade crack locations and crack contours in UAV-taken images.
TL;DR: In this paper, a miniaturized remote-wireless-controlled actuating power supply and dielectric barrier discharge plasma actuator based on car-sticker technology were developed in order to control the airfoil dynamic stall, reduce the strength of the dynamic separation vortex, and increase the aerodynamic efficiency.
TL;DR: In this paper, the effects of the leading edge slat on the aerodynamic performance of the S809 airfoil and the Phase VI blade were investigated and the effect of the geometric parameters were considered.
TL;DR: In this article, the authors presented mathematical modelling of an energy harvester that converts slow mechanical rotation into piezoelectric vibration using a small disk and a pair of magnets for large scale machinery monitoring applications such as wind turbine blades.
Abstract: This paper presents mathematical modelling of an energy harvester that converts slow mechanical rotation into piezoelectric vibration using a small disk and a pair of magnets, for large-scale machinery monitoring applications such as wind turbine blades The harvester consists of a piezoelectric cantilevered beam, a gravity-induced disk, and magnets attached to both the beam and the disk The energy method is used to derive the three coupled equations that describe the motion of the disk, the vibration of the beam, and the harvester voltage output The equations are solved using ODE45 in MATLAB software and verified by the corresponding experimental study The result shows varied energy harvesting performance by blade rotational speed At low blade speed, the harvester generates power by regularized magnetic excitation per blade revolution At high blade speed, however, the disk behavior becomes chaotic to increase excitation force and power generation The results show that the model can quantify power as a function of blade speed, and the proposed harvester can generate a considerable amount of power for self-sustainable sensing and monitoring of wind turbine blades
TL;DR: A novel design method of a direct-drive permanent magnet vernier generator (PMVG) is proposed for a gearless, high-power, and lightweight wind turbine system and the performance characteristics are analyzed with finite-element simulations and compared with analytically predicted results.
Abstract: In this study, a novel design method of a direct-drive (DD) permanent magnet vernier generator (PMVG) is proposed for a gearless, high-power, and lightweight wind turbine system. Once the maximum power requirement is given, the base and maximum speeds of the generator are first obtained from aerodynamic characteristics of the wind turbine blade. Then the necessary electrical circuit parameters of the generator are scoped with consideration of the maximum torque per ampere control scheme of a permanent magnet generator. To determine the generator geometries satisfying the scoped parameters, the correlations between the parameters and geometries of a PMVG with concentrated windings are deduced. Using the deduced correlations and the obtained parameters, a systematic design procedure of a PMVG is proposed. For a case study, a 5-kW DD-PMVG with the outer rotor is designed through the proposed method. The performance characteristics of the designed generator are analyzed with finite-element simulations and compared with analytically predicted results. Finally, the experimental results are provided.