2MW风力发电机轮毂优化设计

优化设计是一种为了让自己的设计材料最省、支出最小的一种技术。通常,在设计中,会有许多的设计方案以供选择,如何从众多的方案中选择一个最好的方案,就需要有较好的设计方法。优化设计的方法有很多,而拓扑优化又称结构布局优化,是一种根据优化目标、载荷及约束而寻求结构材料最佳分配的优化方法。针对2MW风力发电机轮毂进行了拓扑优化,对比分析了优化前后轮毂的质量、及联合工况下的应力和变形,结果表明,联合工况下的应力及变形减小,动态应力最大值减小,动态强度提高;并在三维软件中重建模型,验证优化后模型进行工程实践的可行性。     

风力发电机组轮毂有限元分析与优化

采用叶素动量理论进行风力机气动力学的载荷计算,得到轮毂上的载荷,应用大型通用有限元分析软件MSC系列软件做设计分析平台,对某MW级大型风力发电机组轮毂进行静强度分析、疲劳强度分析,并采用NASTRAN提供的优化程序对轮毂壁厚进行优化设计,探索出了一套轮毂优化设计的方法,并得出一组在一定的工作环境下可以安全工作的轮毂壁厚分布,大大减轻了轮毂重量,降低了加工成本.     

基于拓扑优化的轮毂电机壳体结构轻量化研究

轮毂电机为电动汽车驱动系统核心部件,其结构、强度特性对整车运行稳定性与可靠性具有重要影响,直接决定整车动力性与安全性。根据某电动汽车轮毂电机壳体结构参数、工况及结构特征,建立壳体结构三维力学模型。在对壳体结构系统进行模态分析与静力学分析的基础上,以质量优化为目标,对壳体结构非承载区域进行拓扑优化与结构设计。为验证分析结果,对优化后壳体结构进行模态及静力学分析。结果表明,壳体结构系统质量降低5.5%,系统部分固有频率提高,轮胎轮毂安装螺栓根部局部应力集中得到改善。     

大型风力发电机组轮毂强度分析

轮毂是风力发电机组中受力情况最复杂,且可靠性要求最高的关键部件之一,其强度直接关系到风力发电机组的安全性能。本文根据GL规范,利用有限元方法对轮毂进行静强度和疲劳强度分析,并且给出了轮毂材料S-N曲线的详细拟合过程。有效解决了风机轮毂强度计算问题,为轮毂结构优化奠定基础。     

面向汽车轮毂轻量化设计的组合优化方法

为了达到汽车轮毂轻量化目的,提出了一种将轮毂的概念设计和详细设计相结合的轻量化设计方法。在概念设计阶段,建立三维几何模型和数学优化模型,以轮毂的柔度最小（刚度最大）为目标,体积分数作为约束,利用变密度拓扑优化方法得到轮毂材料的最优结构;在详细设计的阶段,对拓扑优化后的轮毂结构进行二次设计,对二次设计后的轮毂进行有限元仿真验证和尺寸优化。尺寸优化时,为了解决计算量大和优化效率低的难题,引用拉丁方实验采样和多项式响应面技术,在满足轮毂许用强度的前提下建立轮毂的近似模型。最后利用改进的进化算法寻优得到轮毂的最终结构参数并对其进行强度仿真验证。结果表明,经过两次优化后的轮毂在满足强度的条件下,质量减少了20.94%。     

摩托车镁合金轮毂结构优化技术研究

优化摩托车镁合金轮毂不合理的辐板结构,即调节幅板倾角、增加幅板与轮圈的过渡圆角半径,对结构优化前后的镁合金轮毂在相同工况下进行有限元服役应力分析对比。结果表明,结构优化后应力集中主要出现在幅板与轮圈的连接部位,最大应力值从27.1MPa降低到23.1MPa,降幅14.8%,应力集中程度降低较大,应力分布变得缓和,可靠性得到提高。试生产的再设计镁合金轮毂通过了有关权威部门性能检测。结论为轮毂的结构再设计提供了力学依据。     

MW级风力发电机组轮毂连接螺栓接触强度分析

根据认证(GL)规范,运用有限元分析软件,对某MW级风力发电机组轮毂与叶片螺栓连接、轮毂与主轴螺栓连接进行了接触分析.分析了该轮毂连接螺栓在预紧力工况和实际工作工况下的接触强度.总结了基于GL规范对螺栓接触强度分析的方法.     

铝合金轮毂的结构优化及试验分析

针对铝合金轮毂有限元分析模型中的应力集中和强度富余情况,利用ANSYS软件对其进行结构优化,使其应力分布更加合理,达到了提高材料的利用率和减轻自重的目的.优化后的轮毂通过了弯曲疲劳试验、径向疲劳试验和冲击试验,且试验结果与有限元分析结果基本吻合,从而论证了该轮毂研发途径的可行性.     

基于全局优化进行局部优化叠加的大型结构拓扑优化方法研究

针对现有的拓扑优化方法对所指定的设计域内的变量进行全局拓扑优化,从而导致对大型构件拓扑优化时局部区域最佳拓扑结构分布信息丢失的问题,提出一种基于局部结构特性扩散映射的全局拓扑优化方法。该方法首先对设计域内的局部区域进行拓扑优化,得到设计域内局部的优化信息,然后对得到的局部区域优化信息进行整合,得到全局整体的拓扑结构。通过与现有的商业软件ANSYS Workbench和全局优化方法做实验对比,结果表明所提出的优化方法相较于现有的优化方法具有两个优点：第一,所提出的拓扑优化方法可以较好的保留在设计域的局部拓扑结构信息;第二,所提出的拓扑优化方法可以对优化的结构进行尺寸控制。     

Mw级风力发电机轮毂有限元分析

轮毂是风力发电机组中的一个重要部件,载荷情况较复杂,因此对其进行有限元分析显得尤为重要.文童以2MW风力发电机的轮毂为研究对象,通过有限元分析确定了各个部位的应力分布情况和各阶振形,从中得出最危险的部位,为轮毂设计提供了有效的依据.     

大型风力机叶片的耦合优化方法

为了降低兆瓦级风力机叶片的制造成本,通过耦合叶素动量理论与复合材料欧拉伯努利梁强度设计理论,综合考虑风能效率和成本,以叶片的风能效率成本最小化为优化目标,提出了大型风力发电机叶片的多学科优化设计方法。并基于该方法,对某50 m风力机叶片进行了优化设计。研究结果表明,该方法能够找到风能效率与成本的平衡设计点,叶片风能效率成本比传统设计方法设计的叶片减少了8.84%。     

Integrated aero-structural optimization design of pre-bend wind turbine blades

In the optimization design of a pre-bend wind turbine blade, there is a coupling relationship between blade aerodynamic shape and structural layup. The evaluation index of a wind turbine blade not only shows on conventional ones, such as Annual energy production (AEP), cost, and quality, but also includes the size of the loads on the hub or tower. Hence, the design of pre-bend wind turbine blades is a true multi-objective engineering task. To make the integrative optimization design of the pre-bend blade, new methods for the blade’s pre-bend profile design and structural analysis for the blade sections were presented, under dangerous working conditions, and considering the fundamental control characteristics of the wind turbine, an integrated aerodynamic-structural design technique for pre-bend blades was developed based on the Multi-objective particle swarm optimization algorithm (MOPSO). By using the optimization method, a three-dimensional Pareto-optimal set, which can satisfy different matching requirements from overall design of a wind turbine, was obtained. The most suitable solution was chosen from the Pareto-optimal set and compared with the original 1.5 MW blade. The results show that the optimized blade have better performance in every aspect, which verifies the feasibility of this new method for the design of pre-bend wind turbine blades.

     

风力机齿轮箱布局的多目标可靠性优化设计

针对风力机齿轮箱布局设计中存在的问题,采用多目标可靠性优化设计方法,以风力机齿轮箱的箱体体积和齿轮体积最小化为设计目标,建立了风力机齿轮箱布局的多目标可靠性优化设计模型,分析比较了3种常见传动方案对风力机齿轮箱布局的影响,以某型号1.5 MW风力机齿轮箱为例进行了优化分析。研究结果表明,采用该设计方法得到的齿轮箱箱体体积和齿轮体积加权和值比以齿轮体积为目标的单目标设计方法更低。同时,分析结果表明,提高输入转速可大大降低齿轮箱成本。     

Design optimization of wind turbine blades for reduction of airfoil self-noise

To reduce airfoil self-noise from a 10 kW wind turbine, we modified the airfoil shape and planform of a wind turbine blade. To obtain the optimal blade design, we used optimization techniques based on genetic algorithms. The optimized airfoil was first determined based on a section of the rotor blade, and then the optimized blade was designed with this airfoil. The airfoil self-noise from the rotor blades was predicted by using a semi-empirical model. The numerical analysis indicates that the level of the airfoil self-noise from the optimized blade is 2.3 dB lower than that from the baseline blade at the rated wind speed. A wind tunnel experiment was also performed to validate the design optimization. The baseline and optimized rotors were scaled down by a factor of 5.71 for the wind tunnel test. The experimental results showed that airfoil self-noise is reduced by up to 2.6 dB.     

Enhancement of wind turbine aerodynamic performance by a numerical optimization technique

Sectional aerodynamic design optimization was performed to enhance the aerodynamic performance of horizontal axis wind turbine rotor blades based on a computational fluid dynamics technique. The proposed sectional optimization framework consists of airfoil section contour modeling by the PARSEC shape function and a modified feasible direction search algorithm. To enhance the aerodynamic performance of wind turbine rotor blades, the objective of the design framework was set to maximize the lift-over-drag ratio for each design section. A two-dimensional Navier-Stokes flow solver coupled with a transition turbulence model was used to evaluate the aerodynamic performance during the iterative design optimization procedure. The sectional flow conditions were extracted from the flow of a three-dimensional rotor blade configuration. The design framework was applied to the National Renewable Energy Laboratory Phase VI rotor blade. The design optimization was conducted at nine spanwise sections of the rotor blade. To validate the present methodology, the aerodynamic performances of the original baseline rotor and the rotor after the design optimization were compared by using a three-dimensional Navier-Stokes flow solver. It was found that approximately 11% of torque enhancement was achieved after the aerodynamic shape design optimization.     

基于IABC算法的风力机叶片参数优化

为了降低风力机叶片的单位输出能量成本,改善风能利用情况,将风力机叶片的弦长、扭角和相对厚度参数作为设计变量,建立了叶片单位输出能量成本最小的目标函数,运用改进人工蜂群算法(IABC算法)对风力机叶片不同截面进行参数优化,并对叶片单位输出能量成本进行分析和验证。研究表明,某2MW的风力机叶片经优化后,年输出能量增加了0.5%,叶片成本减少了1.9%,叶片单位输出能量成本降低了2.4%。     

A model for yawing dynamic optimization of a wind turbine structure

A novel design optimization model for placing frequencies of a wind turbine tower/nacelle/rotor structure in free yawing motion is developed and discussed. The main aim is to avoid large amplitudes caused by the yawing-induced vibrations in the case of horizontal-axis wind turbines or rotational motion of the blades about the tower axis in case of vertical-axis wind turbines. This can be a major cause of fatigue failure and might severely damage the whole tower/nacelle/rotor structure. The mathematical formulation considers a single pole tower configuration having thin-walled circular cross section with constant taper along the tower height. The nacelle/rotor combination is modeled as a rigid mass elastically supported at the top of the tower by the torsional spring of the yawing mechanism. Adequate scaling and non-dimensionalization of the various parameters and variables are given in order to make the model valid for a variety of wind turbine configurations and types of the material of construction. The resulting governing differential equation of motion is solved analytically by transforming it into a standard form of Bessel's equation, which leads to the necessary exact solutions for the frequencies and mode shapes. Several cases of study are examined for different values of the yawing stiffness and inertia parameters by considering both conditions of locked and unlocked yawing mechanism. Useful design charts are developed for placing the frequencies at their needed target values with no penalty of increasing the total structural weight of the system. In all, the developed model guarantees full separation of the system frequencies from the critical exciting yawing frequencies by proper choice of the optimization design parameters.