Papers by Keyword: Blade

Abstract: A passive control method is proposed for the performance enhancement of a 2D wind turbine blade using the aeroelastic coupling of locally flexible structure (LFS). An aeroelastic model of LFS airfoil is presented using the theory of shallow arch with large deformation. After the verification of numerical algorithm, the interaction between flow and LFS airfoil on the performance is studied with various elastic stiffness. The results show that the unsteady interaction between fluid and structure has a great potential to improve the aerodynamic performance of the airfoil. The lift-drag ratio of the airfoil is enhanced significantly at proper structural parameters, compared with the rigid airfoil. The idea for locally flexible structure can be considered as a smart structure for enhancing the aerodynamic performance of the wind turbine blade.

Abstract: In order to evaluate the separation efficiency of each module in this type of novel combined separator, by PDPA(Phase Doppler Particle Analyzer) we find that under different conditions in 6 combinations, combination 6 (including cyclone + stabilizer + blade+ baffler) has the highest separation efficiency, and there are relatively efficiency valley region in all the 6 combinations. Under the same conditions, the average separation efficiency of the baffler is higher than the blade, and then the blade and baffler have their own advantages in different flowrate. To use stabilizer can effectively improve the flow field inside the separator, restrain and reduce vortex and backmixing, more conductive to the gas-liquid separation.

Abstract: The paper presents a case study on the original solution of a flange shaft as part of the root area of a 5 kW wind turbine blade. There were analyzed the causes that led to the shaft breakage under wind loadings in extreme weather conditions, and consequently technical solutions have been searched in order to improve the shaft design making it more reliable as mechanical strength at extreme wind loadings. The flange shaft is a welded subassembly that keeps the blades attached to the rotor hub. The first part of the paper consists in an analysis referring the loading status, the materials used for blade manufacturing, the identification of critical areas where the breaking was initiated and also the causes for which the materials assumed and specified in the technical design and manufacturing technology failed under loading at wind gusts of about 30 m/sec. Based on this preliminary analysis, the second part of the paper presents the technical solutions which were considered in reference to the materials and the improved design concept aiming to provide the right mechanical strength necessary to withstand specific wind loadings in extreme weather conditions.

Abstract: The effects of high-altitude wind shear of wind speed should be considered, the appropriate number of distribution group should be determined and the distribution of wind speed hybrid model parameters and solving should be loaded onto the blades. When the stress of rotor blade is analyzed, the elastic deformation of the blades and the effects of the vibration of oscillating flow field on reaction of the blades must be considered during the operation. Thus the laws of blade load distribution and the corresponding deformation can be accurately calculated to analyze the interplay between deformation vibration airflow and paddle, to determine the law of deformation of rotor blades, the surface pressure distribution, stress distribution and blade design safety factors. When wind load changes with the wind speed, the adaptive blades are powered by aeroelastic, the law of wielding and flapping of the blade will be studied. The torsion coupling effects of adaptive blade, blade bending ,the law of torsional deformation variation of the angle of attack and the impact on aeroelastic blades structural strength will be explored. The results of this study design will be optimized as the power factor, improving the stability of the design of wind turbine power output, reducing material consumption blades absorb vibration and reducing wind load maneuvering to avoid blade stall achieve pitch control. Thus it provides a theoretical basis for optimal design of strength and stiffness of the elongated paddles.

Abstract: Wind energy technology is an integrated technology, which involves aerodynamics, structural dynamics, meteorology, mechanical engineering, electrical engineering, control multiple disciplines technology, materials science, environmental science and other areas. This paper studies the structural dynamics of the wind turbine. On one hand, modern wind turbine is composed of various interacting components and subsystems, and its aerodynamic rotor design technique involves controlling a wide range of areas systems, mechanical systems, electrical systems. On the other hand, the wind turbine has characteristics different from the usual mechanical systems. Wind turbine power source is natural randomness of strong wind, The leaves are often run in a stall condition. The system has a strong stochastic dynamic process. The transmission system irregular power input is abnormal . The main structural components exposed to several times higher than normal rotating mechanical fatigue loading. Thus the unique characteristic of dynamics of the wind turbine is formed . Analysis of wind turbine blade load dynamics of basic research carried out in this article by means of an appropriate structure coordinates.

Abstract: Gas turbine is a type of rotary engine that consists of compressor, combustion chamber, and turbine sections. This type of engine works in the Brayton Cycle principle that is compression of atmospheric flow, combustion of air-fuel mixture and expanding high temperature combustion flow to generate power output from turbine. The aim of this study is to determine the duct geometry and flow conditions of the gas turbine blades having the internal cooling ducts that acquire highest heat transfer on turbine blades. For different design of internal duct geometries and flow conditions, Fluent solver is used and solutions are validated with Han’s experimental results.

Abstract: As the foundation work of the damage identification for the blade, the purpose of this paper is to determine which parts of the blade are more sensitive to the damage and how serious damage could affect the dynamic response of the blade structure. Several damage states are simulated using the magnets, and then the distributed fiber Bragg grating sensor system is used to measure the dynamic strain response of the blade under the random excitation. The dynamic strain time domain signal is first analyzed, and then the different damage states are identified. In order to eliminate the adverse affect of the environmental and operational variations, the Hilbert-Huang Transform method is used to extract the damage-induced signal component. Lastly the damage index based on the autoregressive model and Mahalanobis distance method is constructed to detect damage. Some conclusions are obtained from the experimental results.

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.

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.

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.