Papers by Keyword: Blade

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Authors: Lei Lu, Li Da Zhang
Abstract: To quickly and easily get a smooth and accurate 3D model of blades, This paper was based on the two-dimensional wooden patterns of the existing francis turbine blades in "AutoCAD", by importing UG software platform, directly translating two-dimensional lines to get three-dimensional wooden patterns, without calculating the spatial coordinates of distribution points on the blade section lines, obtaining the optimized smooth pressure sides and suction sides of the blades by characteristic surface intersecting lines, after partial rounding and sewing the sheets, the process of three-dimensional modeling of blades was finally completed. This takes a solid foundation for hydraulic performance prediction and CFD numerical simulation analysis of the francis turbine. The blade modeling method described in this article has some reference value.
Authors: Wei Cong, Shi Ping Song
Abstract: In this paper, the main design parameters of 750 kw horizontal-axis wind turbine wheel are computed based on simplified theoretical design model; The airfoil coordinates of the blade derived from Profili are spatial switched in Excel, then the spatial coordinates of every foline are obtained; In SolidWorks, the curves of foline outlines are drawn on the basis of former coordinates. Eventually, the 3D model of the blade is created by loft surfacing according to the foline outlines. The blade model created in this paper could be used in the coming finite element analysis.
Authors: G. X. Qi, Rui Bin Mei, F Wang, L Bao
Abstract: In order to predict the microstructure evolution and grain size of GH4169 alloy blade in finish forging process and optimize the parameters, a coupled simulation between thermal mechanical and microstructure evolution was realized through embedding the developed user subroutines into the DEFORM-3D software. The temperature, equivalent strain, dynamic recrystallization fraction, average grain size and grain size distribution were predicted and discussed. The experimental results of microstructure under the same forging condition were investigated. The average grain degree in the blade rabbet and body are 8 and 10 respectively. The calculated results of microstructure have a good agreement with the measured value from experimental data and the prediction error of average grain size is less than 6.7%. The developed program is reliable and the accuracy is satisfying. The distribution of grain size along the blade body is decreased from the middle to the leading and back edge. The shape and microstructure after finish forging under the condition of technology parameters meet the user’s requirement. Keywords: Blade, GH4169 alloy, Numerical simulation, Microstructure, Forging
Authors: Jian Jie Zhang, Wen Lei Sun
Abstract: This paper on wind generator set blades had a simple introduction, and the modal analysis was used on the blades dynamic analysis, the conclusion that blades the different stage in the direction of the force and deformation was drawn, it can be concluded: the first three-order natural frequency at, the blades are expressed as a pure bending vibration. It can be seen from the blade vibration figure: a frequency of blades waving in the direction of the first natural frequency, first natural frequency of the second-order frequency blades shimmy direction, three frequencies for the blades waving direction of the second-order natural frequency, torsional frequency of fourth order for the direction of the shimmy, five order of frequency of blades placed waving direction of the three natural frequencies. According to the theory of vibration, the vibration in the process of energy is concentrated in bands 1 and 2, so the first stage waving vibration (bending vibration) is the main vibration of the wind generator set blades; 4 and 5 vibration modes performance for bending dominated accompanied shimmy and torsional vibration. Visible, the shimmy vibration and torsional vibration in high-end part is still not the main vibration.It provides the theoretical basis so as to improve the quality of the design of wind turbine blades. Blade is one of the wind generator set key components, many aerodynamic problems are faced, the aerodynamic efficiency of the blades is to be considered an important factor in the blade design, and their job security is more important factor. The wind turbine power source is the natural randomness of strong wind, the blades often run in the stall condition, the system has a strong stochastic dynamic process, the transmission of abnormal is irregular power input, the main structural components to withstand higher than normal rotation mechanical fatigue loading several times, forming a unique wind turbine dynamics. Wind generator set blades as a flexible structure, the load acting on has a cross and random variability, which is an inevitable occurrence of vibration, the vibration characteristics of their study is very necessary. Blades the structure and strength of the wind generator set reliability plays an important role. With the emergence of high-power wind generators, finite element numerical analysis of the theories and methods have been applied to the structural design of wind generator set. Modern wind generator set blades shape and internal structure complex calculations,it is necessary to study the exact dynamics model and the analysis of blades structure [. The institutional dynamics is to constitute the institutional elements of the inertia and institutions in the rigid parts caused by the vibration of a subject. The kinetic analysis features include: regular modal complex eigenvalue analysis, frequency and transient response analysis, (noise) acoustic analysis, random response analysis, the response and the impact of spectrum analysis, power sensitivity analysis. Here only the blade to vibrate and modal to be analysed [.
Authors: Ka Tian, Shi Ming Wang, Chao Lv
Abstract: Used a new type horizontal wave flow turbine ocean energy device as a prototype for the tank experiment, theoretically analyzed the fluid dynamics and energy capacitation of its key component turbine. Through analyzing the data of the tank experimental of the key component turbine, we found the feasibility of this kind of power device. Besides, the experiment proved a particular characteristics of the turbine of maintaining the same rotational direction whatever the directions of the incoming flow of this kind of turbine. The feature of the turbine can eliminate the complicated steering mechanism, which helped the whole device with the advantage of simple structure. The tank experiment not only provided a practical foundation for optimizing the generating device, but also gave a reference method to solve the similar engineering problems.
Authors: Bo Zhou, Chang Zheng Chen, Yan Ling Gu, Hao Zhou
Abstract: Abstract. To extract the AE signal feature effectively, an automatically operating blind source separation method is presented. The blind deconvolution algorithm is discussed for the non-stationary AE signals to eliminate the noise through minimizing the mutual information to get the separating matrix. Finally, the experimental result is indicated that the mixing noise of the AE signals in the collecting process can be eliminated by this method, and the individual extensional and flexural wave modes can be separated, which can provides the theory analysis basis for the crack recognition of wind turbine blade.
Authors: Lei Zhang, Xiao Dan Tan, Qiang Yuan, Shi Jun Ji
Abstract: An adaptive planning method for measuring points of blade section line is presented due to the less distribution of measuring points along the blade edge specified by chordal tolerance method which results in the edge information loss. Based on the chordal tolerance method, the adaptive planning method provides the number and distribution of measuring points along the blade section line on condition of the given initial number of measuring points and threshold value of chordal tolerance. A simulation system based on MATLAB is developed to compare the adaptive planning method with the chordal tolerance method. The measuring tests of blades are carried out according to the measuring points specified by chordal tolerance method and by adaptive planning method respectively. The simulation and measuring results indicate that the distribution of measuring points along the blade edge specified by adaptive planning method is more reasonable than those by chordal tolerance method and that the total number of measuring points is reduced considerably and the measuring efficiency is increased by adaptive planning method.
Authors: Guang Hua Chen, De Tian, Ying Deng
Abstract: With 3MW composite blade wind turbine blade as an example, according to the momentum blade element theory, optimized the design of aerodynamic shape, established the Three-dimensional model of blade through coordinate conversion, and made the stress check of structure and modal analysis using the finite element method, and more detailed description of the design methods and techniques of large composite wind turbine blades
Authors: De Tian, Guang Hua Chen, Qi Li
Abstract: Take maximum power output of blade element as design target, establish a optimization model of variable pitch wind turbine blade. Using the adaptive genetic algorithm to search for to overcome the shortcomings of early maturity and poor stability, it can reach more close to the global optimum than the classical genetic algorithm. Use this method to design a 3MW variable pitch wind turbine blade, the results show that this optimization model is correct and the method is practical.
Authors: K. Shirvani, Amir Firouzi
Abstract: The diffusion aluminide coatings are widely used in the air-cooling passages to protect their surfaces against high temperature corrosion. In this study plain and Si-modified aluminide coatings were applied by slurry technique on internal surfaces of Ni-base GTD-111 superalloy cylindrical specimens derived from a gas turbine air-cooled blade. The slurries containing Al or Al plus Si powders were applied on internal surfaces by injection method. Then, the samples were heated to high temperature (800-1000°C) to form the coatings. Optical, SEM-EDS, and XRD were utilized for characterizing microstructures and phase compositions of the coatings. The thicknesses of applied coatings on internal surfaces were in the range of 30-50 μm that meets specifications for diffusion coatings in such application (i.e. 25-756m). The examinations demonstrated that both coating types were contained β-NiAl phase as the matrix. The uniformities of coatings applied on different surface positions of passageway were determined. In addition, the effects of time and temperature of coating process as well as mass of dried slurry on the coating thickness were also discussed.
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