Optimized Design of Bio-Inspired Wind Turbine Blades

To enhance the aerodynamic performance of wind turbine blades,this study proposes the adoption of a bionic airfoil inspired by the aerodynamic shape of an eagle.Based on the blade element theory,a non-uniform extraction method of blade elements is employed for the optimization design of the considered wind turbine blades.Moreover,Computational Fluid Dynamics(CFD)is used to determine the aerodynamic performances of the eagle airfoil and a NACA2412 airfoil,thereby demonstrating the superior aerodynamic performance of the former.Finally,a mathematical model for optimizing the design of wind turbine blades is introduced and a comparative analysis is conducted with respect to the aerodynamic performances of blades designed using a uniform extraction approach.It is found that the blades designed using non-uniform extraction exhibit better aerodynamic performance.

The Design of Stall-Regulated Wind Turbine Blade for a Maximum Annual Energy Output and Minimum Cost of Energy Based on a Specific Wind Statistic

The design of a stall-regulated wind turbine to achieve a maximum annual energy output is still a formidable task for engineers. The design could be carried out using an average wind speed together with a standard statistical distribution such as a Weibull with k = 2.0. In this study a more elaborated design will be attempted by also considering the statistical bias as a design criterion. The wind data used in this study were collected from three areas of the Lamtakong weather station in Nakhonratchasima Provice, the Khaokoh weather station in Phetchaboon and the Sirindhorn dam weather station in Ubonratchathani, Thailand. The objective is to design a best aerodynamic configurations for the blade (chord, twist and pitch) using the same airfoil as that of NREL Phase VI wind turbine. Such design is carried out at a design wind speed point. Wind turbine blades were optimized for both maximum annual energy production and minimum cost of energy using a method that take into account aerodynamic and structural considerations. The work will be carried out by the program “SuWiTStat” which was developed by the authors and based on BEM Theory (Blade Element Momentum). Another side issue is the credibility of the Weibull statistic in representing the real wind measurement. This study uses a regression analysis to determine this issue.

Analogy Theory and Application of Pressure Difference of Wind Turbine Blade Profile

This paper aims to design an optimized blade for Horizontal Axis Wind Turbine(HWAT).Since airfoil is a basic component of blade design,an optimized airfoil(referred as SJX)was proposed based on the line theory through the weight analogy to pressure distribution of air flow.Its lift,drag,lift⁃to⁃drag ratio were compared with those NACA2409⁃34,NACA2410,and RK40 airfoils by using Profili software at fixed wind velocity and under different angles of attack.The NACA2409⁃34 airfoil was found to be greatly similar with the SJX airfoil.Based on the Wilson method,blades using SJX and NACA2490⁃34 airfoils were developed and different performance parameters such as velocity distribution,pressure distribution,and power were compared under variable wind velocities and different angles of attack ranging from-4°to 6°at different radius from the center of rotor using computational fluid dynamics(CFD)in ANSYS FLUENT.Results of the study suggested that the performance of the SJX based airfoil and blade was much more optimized.

Performance Investigation of Three Combined Airfoils Bladed Small Scale Horizontal Axis wind Turbine by BEM and CFD Analysis

The present work is based on the comparative study between “Blade-Element- Momentum” (BEM) analysis and “Computational-Fluid-Dynamics” (CFD) analysis of small-scale horizontal axis wind turbine blade. In this study, the pitch is considered as fixed and rotor speed is variable. Firstly, the aerodynamic characteristics of three different specialized airfoils were analyzed to get optimum design parameters of wind turbine blade. Then BEM was performed with the application of the open source wind turbine design and performance computation software Q-Blade v0.6. After that, CFD simulation was done by Ansys CFX software. Here, k-ω “Shear-Stress-Transport” (SST) model was conducted for three-dimensional visualization of turbine performance. However, the best coefficient of performance was observed at 6o angle of attack. At this angle of attack, in the case of BEM, the highest coefficient of performance was 0.47 whereby CFD analysis, it was 0.43. Both studies showed good performance prediction which was a positive step to accelerate the continuous revolution in wind energy sector.

Criterion of aerodynamic performance of large-scale offshore horizontal axis wind turbines

With the background of offshore wind energy projects, this paper studies aerodynamic performance and geometric characteristics of large capacity wind turbine rotors （1 to 10 MW）, and the main characteristic parameters such as the rated wind speed, blade tip speed, and rotor solidity. We show that the essential criterion of a high- performance wind turbine is a highest possible annual usable energy pattern factor and a smallest possible dimension, capturing the maximum wind energy and producing the maximum annual power. The influence of the above-mentioned three parameters on the pattern factor and rotor geometry of wind turbine operated in China＇s offshore meteoro- logical environment is investigated. The variation patterns of aerodynamic and geometric parameters are obtained, analyzed, and compared with each other. The present method for aerodynamic analysis and its results can form a basis for evaluating aerodynamic performance of large-scale offshore wind turbine rotors.

Design of Wind Turbine Blade for Solar Chimney Power Plant

Aiming at the global efficiency of solar chimney power plant(SCPP), we design a wind turbine generation device to elevate its electricity generating efficiency. Based on wind power utilization theory, a new method is proposed to design a type of wind turbine blade for SCPP. The lift and resistance coefficients on different Reynolds numbers of NACA4418 airfoil, which is suitable for experimental solar electricity generation system, are determined by Profili-V2.0 airfoil design software, a program written in Matlab to calculate chord length of the airfoil. The optimization is conducted by class-shape-transformation(CST) parameterization method and Xfoil software. An airfoil design program is designed on the basis of blade element theory and attack angle with the highest lift coefficient to iteratively determine the inflow angle and setting angle. Prandtl's tip-loss factor is applied to correct the setting angle, after the airfoil data are input into AutoCAD to build an airfoil model which is then imported into Solidworks to draw blades. A new way is put forward to design wind turbine blades in SCPP.

Optimization design of spar cap layup for wind turbine blade

Based on the aerodynamic shape and structural form of the blade are fixed,a mathematical model of optimization design for wind turbine blade is established.The model is pursued with respect to minimum the blade mass to reduce the cost of wind turbine production.The material layup numbers of the spar cap are chosen as the design variables;while the demands of strength,stiffness and stability of the blade are employed as the constraint conditions.The optimization design for a 1.5 MW wind turbine blade is carried out by combing above objective and constraint conditions at the action of ultimate flapwise loads with the finite element software ANSYS.Compared with the original design,the optimization design result achieves a reduction of 7.2%of the blade mass,the stress and strain distribution of the blade is more reasonable,and there is no occurrence of resonance,therefore its effectiveness is verified.

Study on the Rotor Design Method for a Small Propeller-Type Wind Turbine

Small propeller-type wind turbines have a low Reynolds number,limiting the number of usable airfoil materials.Thus,their design method is not sufBciently established,and their performance is often low.The ultimate goal of this research is to establish high-performance design guidelines and design methods for small propeller-type wind turbines.To that end,we designed two rotors:Rotor A,based on the rotor optimum design method from the blade element momentum theory,and Rotor B,in which the chord length of the tip is extended and the chord length distribution is linearized.We examined performance characteristics and flow fields of the two rotors through wind tunnel experiments and numerical analysis.Our results revealed that the maximum output tip speed ratio of Rotor B shifted lower than that of Rotor A,but the maximum output coefficient increased by approximately 38.7%.Rotors A and B experienced a large-scale separation on the hub side,which extended to the mean in Rotor A.This difference in separation had an impact on the significant decrease in Rotor A's output compared to the design value and the increase in Rotor B's output compared to Rotor A.

基于Qblade和Matlab的风力机叶片设计与气动性能分析

首先使用Qblade计算翼型的气动参数,将数据进行处理后,利用Wilson设计模型,结合Matlab编程软件对某小型风力机叶片进行设计。再基于叶素动量理论,利用Qblade对所设计的叶片进行气动性能计算,并根据weibull风速分布模型计算风力机的性能。计算结果表明:编写的程序正确,Qblade风力机性能计算软件能正确反映叶片气动模型,并在保证计算结果准确的同时节省风力机叶片设计前期计算的时间。

气动翼型涡流发生器与风力机翼型同步优化设计

针对目前风力机叶片翼型与涡流发生器相互独立的串行设计方法,导致不能最大限度的设计出气动性能最佳的风力机新叶片加装新型涡流发生器。这里提出带气动翼型的涡流发生器与风力机叶片翼型同步设计方法,利用B样条函数分别表达叶片翼型与涡流发生器气动形状,以最大升阻比及失速前最大升力系数为多目标函数建立优化数学模型,结合CFD技术与粒子群算法对原始叶片翼型DU97-W-300与CLARKY翼型涡流发生器进行同步优化,优化结果表明:相比原始叶片翼段加装CLARKY翼型涡流发生器,优化后的升力系数为2.378,提高了9.3%,升阻比为63.335,提高了7.5%;且对优化前后的流线图及涡量云图进行了对比分析,说明优化后叶片加装涡流发生器翼型可产生更大的诱导涡,能够有效抑制叶片表面流体分离。这里研究对于叶片与涡流发生器的设计及应用具有很好的参考与借鉴意义。

神经网络正逆预测结合的风力机叶片强度可靠性研究

针对风力机叶片在各基本随机变量相互影响下强度极限状态难以界定的问题,提出广义回归神经网络正逆预测结合的风力机叶片强度可靠性分析方法。通过神经网络逆预测模型估算叶片失效时各随机变量状态,利用有限元分析法校核后作为强化样本用于神经网络正预测模型的训练。将该方法构建的神经网络模型与通过更多随机样本构建的模型进行比较。结果表明:前者的学习样本数量减少26%,测试集均方误差降低48.19%,平均绝对百分比误差降低58.24%,因此通过该方法构建的神经网络模型在叶片失效边界区域具有更好的预测性能。利用该模型计算叶片的强度可靠性,进一步验证了该方法的有效性。

风电叶片内窥机器人结构设计与运动仿真

针对风电叶片前缘空间不规则、直径变化范围大的特点,文中制订了内窥机器人设计要求,提出以履带式行走机构和剪叉式变径机构为基础的设计方案,分别建立两种不同的内窥机器人三维模型,详细介绍了两种内窥机器人结构及各部件功能。机器人主要由行走模块、变径模块和支撑模块构成,具有大范围变径、小范围随形支撑和差速转向能力。机器人本体配有可移动电源并可进行无线控制,搭载检测设备可以对前缘空间进行检测。最终对机器人变径机构进行运动仿真,结果表明:机器人工作直径为395~1492 mm,满足设计要求。

风力发电机组叶片疲劳失效的研究进展

提升风力发电机组叶片的抗疲劳性能对风电机组的长寿命服役与可靠性运行具有重要意义,已成为当前的研究热点。本文较全面地综述了风力发电机叶片的抗疲劳技术相关研究,总结了叶片疲劳载荷的计算方法,分析了影响叶片疲劳性能的各种因素,介绍了叶片疲劳探伤技术,阐述了叶片寿命预测和叶片优化设计的相关研究进展。叶片疲劳载荷分析是评估风力机叶片疲劳失效的重要手段,该分析能为制定针对性的维护计划和改进设计提供关键依据;叶片材料、褶皱、外界环境等因素对叶片抗疲劳性能的影响巨大;叶片疲劳探伤技术在叶片健康监测和维护中起着至关重要的作用;基于Palmgren-Miner线性理论的疲劳寿命预测可有效提高叶片的可靠性;通过采用先进的设计方法和结构改进,可以降低叶片的疲劳应力,提高叶片的强度和使用寿命。

风电叶片主梁结构的多尺度可靠性优化设计

针对风电叶片大型化所引起的材料性能不足以及可靠性难以保证等问题,研究了碳纤维复合材料在风电叶片中的应用和主梁结构的优化设计。基于复合材料的多尺度特征,使用代表体积单元(RVE)的均匀化方法预测其等效弹性属性;建立一个主梁结构的参数化有限元分析模型,对其在挥舞和摆振两个加载工况下进行分析;将位移、应力、等效塑性应变等响应作为约束函数,建立以轻量化为目标的可靠性优化模型。结果表明,经过可靠性设计优化后的风电叶片主梁结构满足可靠性和轻量化的要求,且其各部分材料的性能得到了充分的发挥。

水平轴风力机叶片的逆向设计与分析

作为一个专用程序,PROPID在水平轴风力机叶片的逆向设计与分析中有许多独特的优点。本文在介绍PROPID程序的同时,选取一风力机叶片为计算模型,使用PROPID进行重新优化设计和分析。通过分析比较发现,PROPID程序在叶轮的功率计算、外形几何尺寸设计、最佳安装角和转速的确定方面均有较好表现,并能正确反映风机叶轮的气动理论,是一种很实用的风力机叶轮逆向设计和分析程序,对提高风力机的气动设计水平、缩短设计周期有很大帮助。

一种水平轴风轮叶片的气动设计方法

发展了两种先进的水平轴风轮叶片气动计算和设计方法—— PROPGA和 PROPID。PROPGA是基于最优化方法的遗传算法 ,用于最初的叶片选择和几何设计 ;PROPID是一种基于反问题的叶片气动设计方法 ,用于最后的叶片造型和性能预估。给出了两个实例 ,一个是以基础科学研究为目的的实验探索用全新风轮 ,另一个则是用于商业生产的小型风轮。在实际风轮设计中的成功使用证明 ,PROPID和 PROPGA是一种强有力的设计工具 。

海上风电装备产业基地生产设施设计

以某大型海上风电智能化装备产业园为例,概述风电产品的主要参数、风电机组和叶片的生产能力规划与特点,并据此分析其工艺流程和生产设施,拟定机组总装车间和叶片制作车间的工艺区划方案。在此基础上,基于工时计算确定工序工位数,结合工位尺寸形成车间的工艺布置,完成生产设施设计,为我国海上风电装备产业基地的规划建设提供参考。

基于多岛遗传算法和动量叶素理论的风力机叶片外形优化设计研究

通过调整标准NACA翼型的控制参数建立风力机叶片翼型,采用加权平均法定义优化目标函数,建立叶片外形优化模型。采用多岛遗传算法对优化模型进行求解,获得优化后翼型参数。采用Fluent软件对优化前后的风力机叶片压力梯度、气动性能进行仿真,结果表明,优化后风力机叶片的输出功率与风能利用系数增大,叶根处的弯矩减少。

一种实用的风力机叶片气动设计方法研究

提出了水平轴风力机叶片的优化设计模型,该模型以风轮平均年能量输出最大为设计目标,并将风速的概率分布考虑进来。为了获得较好的优化结果,首先采用PROPID程序对叶片进行反设计,获得较好性能的叶片几何,在此基础上,运用遗传算法进行搜索寻优,这样不仅减小了搜索的范围,也降低了搜索的时间。对叶片面积附加约束,以获得符合实际的叶片,采用5阶贝塞尔函数在设计点之间进行插值,以获得光滑的几何外形。利用该方法优化设计了600kW风力机叶片。与已有叶片相比,优化结果显示了明显的优越性,验证了该优化方法的有效性和实用性。

风力机叶片的形状优化设计

在风力机优化设计过程中,考虑法向力和切向力的叶尖损失,基于一维的动量叶素理论及传统的风力机空气动力学原理,推导并给出新的风力机轴向和周向因子的计算模型。探讨风力机成本和输出能量之间的关系,得到风力机成本及其年输出能量的计算模型,进而建立风力机单位输出能量成本的数学模型,以其为优化设计目标,以叶片的形状参数弦长、扭角和相对厚度为优化设计变量,提出叶片的优化设计数学模型。最后,应用该优化模型对某2MW风力机叶片进行优化设计,并对优化结果进行比较分析,验证了优化叶片的工作性能,很好地实现了风轮单位能量成本的降低。研究成果为大功率风力机叶片的设计开发提供了理论依据,奠定了风力机叶片的研究和工业应用前景。