共查询到19条相似文献,搜索用时 890 毫秒
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大型水平轴风力机叶片气动性能优化 总被引:2,自引:0,他引:2
为提高风力机将风能转化为机械能的效率,根据我国西北地区的风频风能曲线,用最优设计攻角沿叶片轴线的非线性分布修正传统Wilson算法,优化设计大型水平轴风力机叶片的气动性能. 该优化设计利用Matlab优化工具箱,优化速度干涉因子的迭代计算,提高计算效率;考虑多翼型和变攻角等因素对叶片外形优化的影响,从结构及加工工艺角度修正翼型. 通过对1.2 MW 风力发电机组叶片外形的气动性能计算和优化设计,结果表明该优化设计的有效性和可行性,可为风力机叶片外形设计提供参考. 相似文献
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改善风力机叶片气动性能,提高叶片刚度、稳定性,已成为大型风力机叶片设计迫切需要解决的问题。生物体独特的外部形状、功能、结构、材料的完美统一,高超的环境适应能力,也为风力机仿生设计提供了不竭灵感。仿生过程是一个分析综合创新的过程,运用TRIZ产品进化理论对风力机叶片技术所处发展阶段进行研究,有助于更清楚地了解风力机叶片的发展趋势和创新的必要性,使研究工作更具系统性和规律性。应用TRIZ产品进化理论,对风力机叶片技术的相关专利数据进行统计并绘制曲线图,通过与标准曲线的区段比较找出风力机叶片所处的发展阶段和接下来的发展趋势与对策。将鱼鳍作为仿生对象进行建模与力学分析,得到仿生模型的力学指标。 相似文献
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本文针对风力机叶片气动外形的设计现状,采用Schmitz设计模型,结合小型叶轮设计实例,提出了风力机叶片的三维设计方法。利用图形几何变换原理求解叶片各截面叶素的空间坐标,运用三维设计平台进行叶片三维实体建模,设计过程交叉组合,提出了三种设计方法,并分析了各自的特点。方法具有普适性,有助于提高叶片的设计质量和设计效率,为叶片气动外形的三维快速设计提供了参考。 相似文献
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针对目前风力机叶片缺陷检测方法检测精度低、危险系数大、设备价格高等问题,提出一种基于LabVIEW+无人机的风力机叶片缺陷检测系统,实现了硬件平台搭建和系统软件设计,对图像处理算法进行研究,针对传统二值化算法中不同颜色风力机叶片阈值不同的问题,提出了应用边缘提取的检测方法。通过理论分析和实验对比了LabVIEW中边缘提取缺陷检测算子及组合算子的检测效果,并最终确定Sobel算子应用于本风力机叶片缺陷检测系统。实验表明,该系统能够实现不同颜色风力机叶片缺陷的自动、低成本检测,检测精度高达93%。 相似文献
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针对传统水平轴风力机叶片气动外形建模与结构特性分析,大多采用不同的基函数,从而使叶片可动边界及结构分析模型存在较大误差,进而影响计算精度与求解效率等问题,利用等几何分析法将叶片几何形状与结构模型无缝连接,直接将叶片气动外形的非均匀有理B样条(NURBS)控制向量作为叶片结构控制参数,通过与有限元方法对比,两种方法得出位移最大值偏差为6.133%,应变最大值偏差为6.277%,最大值点位移与应变随时间变化趋势都呈线性变化,直线斜率K值近似相同,验证了等几何分析的正确性与可行性。 相似文献
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在额定风速以上时,为保证风电机组的安全稳定运行,需要降低风力机捕获风能,使风力机的转速及功率维持在额定值,基于微分几何反馈线性化方法,提出变桨距风力发电机组恒功率控制策略.建立了风力机的仿射非线性模型,采用微分几何反馈线性化变换实现全局精确线性化;根据新的线性化模型,以风力机转速为输出反馈变量,叶片桨距角为输入控制变量,设计桨距角控制器;在风速高于额定值时调节风力机维持在额定转速,从而实现额定风速以上的恒功率控制.仿真结果表明,所提控制策略能较好地解决变桨距风力发电机组额定风速以上的恒功率控制问题,控制方法具有较好的适应性和鲁棒性. 相似文献
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针对大型风力机叶片在静止和变速运转工况下,振动模态计算分析方法和转速对频率的影响进行了研究.建立了叶片有限元模型,静力分析时采用耦合加载方式;采用分块Lanczos法分析了叶片的模态,考察了叶片固有频率对预应力效应的敏感程度及稳定性,探讨了转速对叶片频率的影响程度,分析了预应力效应产生的原因.结果表明:叶片主要以挥舞和摆阵振动形式为主;预应力效应对叶片的固有频率产生了较大影响,随转速的不断增大叶片的固有频率也随之增大,且预应力效应对叶片挥舞刚度的影响程度大于摆阵刚度的影响. 相似文献
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M. Z. Dosaev L. A. Klimina B. Ya. Lokshin Yu. D. Selyutskiy 《Journal of Computer and Systems Sciences International》2014,53(3):402-409
A wind turbine with a horizontal rotation axis is considered in the stationary airflow. A problem of choosing the law of change of the setting angle of the cross section of the wind turbine blade and the value of the angular speed so that the wind energy utilization coefficient is maximal is discussed. Maximization of the respective functional is considered as a variational problem with a priori unknown parameter. Once it is solved numerically or analytically, the optimal value of this parameter is determined, with the sought variables given by rather simple formulas. The results are analyzed on a qualitative level. In particular, the setting angle is found to change monotonically along the blade, which is confirmed by practical wind turbine design. Examples of using the proposed approach to wind turbine blade design are considered. 相似文献
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A viscous lift theorem is derived from a momentum balance and Stokes’ theorem around one section of a wind turbine blade. The theorem is a generalization of the classical Kutta–Zhukovsky lift theorem for the viscous near-field and is validated for 2-D attached and separated flow. The application of the viscous lift theorem within a coupled Navier–Stokes/vortex-panel solver gives insight into the complex 3-D aerodynamics pertinent to wind turbines. 相似文献
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变桨距风力机在不同风速下具有不同的运行状态和输入输出关系.文章根据空气动力学理论研究了风力机静动态特性;探讨了不同风速下,变桨距风力机的控制方案及运行状态;根据变桨距风力机不同的运行状态,设计了发电机特性和桨距角控制方案;在matlab/simulink环境下,建立了适应变桨距风力机全状态的模拟系统;在匀速风、阵风、渐... 相似文献
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《Computers & Structures》2007,85(11-14):1072-1079
The vortex method has been extended to account for blade flexibility, which is a potential source of unsteadiness in the flow past a wind turbine rotor. The code has been validated previously under the assumption of rigid blades. The aerodynamics method is based on the Goldstein model, which distributes the flow vorticity on rigid helicoidal surfaces defined uniquely by the flow parameters (tip speed ratio and average power extracted by the rotor) and the blade geometry (maximum radius and root lengths). The structure is treated as a beam with degrees of freedom in bending and torsion. The high twist of the wind turbine blades is responsible for induced velocities in the plane of the rotor as well as out of plane. A modal decomposition has been shown to be the most accurate and efficient approach for an implicit coupling of the structural and aerodynamics equations. Results for a homogeneous blade are presented for a low speed of 5 m/s and yaw angles of 0°, 5° and 10° and compared with rigid blade results and experiments of the National Renewable Energy Laboratory (NREL). The nonhomogeneous NREL blade has also been modeled and results are presented for V = 8 and 10 m/s at zero yaw that include the effect of the tower on the blade loading. 相似文献
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Srdjan Jovi 《Engineering with Computers》2020,36(2):597-602
Horizontal-axis wind turbines (HAWT) have the constant rotor speed, while the blade tip speed changes continuously. This could reduce power performance of the wind turbine. In this paper, the accuracy of soft-computing technique was employed for aerodynamics performance prediction based on continuously variable-speed horizontal-axis wind turbine with optimal blades. The process, which simulates the $$\varphi$$ (relative wind angle), BEP (blade element parameter), SP (solidity parameter), CPtot (total power coefficient), CPl (local power coefficient), and CT (local thrust coefficient), with adaptive neuro-fuzzy inference system (ANFIS) was constructed. The inputs were local speed ratios λr and different values of drag-to-lift ratio ε. The performance of proposed system is confirmed by the simulation results. The ANFIS results are compared with the experimental results using root-mean-square error and coefficient of determination and Pearson’s coefficient. The experimental results show that an improvement in predictive accuracy and capability of generalization can be achieved by the ANFIS approach. The effectiveness of the proposed strategies is verified based on the simulation results. 相似文献
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超声速飞行器外表具有大量的蒙皮壁板结构,其在巡航过程中会受到气动、热、声及机械等载荷的联合作用.本文针对超声速气流中的复合材料壁板结构,基于一阶剪切变形理论(First-Order Shear Deformation Theory,FSDT)和超声速活塞理论,推导得到了复合材料壁板的气热弹动力学的能量泛函,并运用Hamilton原理变分求得系统的控制方程,利用牛顿迭代法结合Newmark法,求解获得了壁板的临界颤振动压和时域动力学响应.通过变参数计算,分析了不同参数对于壁板动力学响应的影响.最后,应用非线性能量阱(Nonlinear Energy Sink,NES)对复合材料壁板的动力学响应进行颤振控制,结果表明,NES可以有效降低壁板的颤振极限环振幅,从而极大提高超声速飞行器的可靠性和寿命. 相似文献
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搭建小型风机叶片振动检测实验平台,采集风机叶片振动响应数据,利用自互功率谱法辨别叶片损伤前后的模态参数,通过实验数据对比风机叶片损伤前后固有频率的变化,当风机叶片发生损伤时,其各阶固有频率会下降,且随着损伤程度的增加,各阶固有频率的下降幅度越大,并利用轴向振型差法对叶片损伤进行了定位,在实验室条件下完成了风机叶片结构损伤的识别。 相似文献