基于VB的风力机叶片外形优化设计

为了实现风力发电机风轮叶片外形的优化设计,以风场风速分布为基础提出了综合优化目标;以片条理论为基础提出了以展弦比为关键参数的修形约束条件的气动优化目标,建立了叶片外形优化设计的数学模型.采用枚举法和循环结构,选用Access数据库,应用Visual Basic编制程序实现叶片外形的优化设计.针对内蒙古某地区设计了1.5MW风力机叶片,与国外同功率某通用叶片进行了对比分析.结果表明,两种叶片外形基本吻合,而且文中设计的叶片在性能上有明显优势,同时也验证了文中提出数学模型的可靠性和程序的实用性.     

基于参数化的涡轮叶片三维气动优化仿真

为了提高涡轮叶片的设计效率,在分析已有涡轮叶片截面线参数化造型技术优缺点的基础上,基于B样条曲线实现了涡轮叶片截面线的参数化造型和参数化修改,并编写了叶片造型程序,实现了叶片流场模型的自动化生成.以某型号涡轮叶片为例,对其进行三维流场数值模拟,然后采用遗传算法和序列二次规划法算法的组合,以涡轮的气动效率为目标函数,对涡轮叶片进行了气动优化.算例结果表明文中所建立的涡轮叶片自动优化设计体系是可行的.     

MATLAB在风电设备设计中的应用

以Willson叶片优化设计方法为基础,给出风力发电机叶片优化设计的数学模型。以MATLAB高级语言为工具开发了设计计算和性能计算的程序,给出了程序框图。将所开发程序应用于机械工程,获得了良好的效果。     

平流层飞艇外形的设计优化

平流层飞艇是依靠浮力升空的飞行器.飞艇外形对于平流层飞艇的设计至关重要,为了获得能够满足动力结构和重量等各个学科要求的最优艇形,将综合设计优化技术引入到飞艇外形设计中,提出了适用于优化的飞艇外形生成曲线,分析了与外形有关的气动、结构和重量等因素,建立了飞艇气动阻力、表面积和最小环向应力的模型,构造了复合目标函数,并针对某飞艇外形进行了优化设计.仿真结果证明,利用蒙特卡罗算法优化设计后的艇形优于传统艇形.     

基于遗传算法的UUV线型多目标优化设计

基于遗传算法的多目标空间区域内的探索性全局优化技术,将阻力系数、丰满度与最大减压系数发生位置作为综合判定指标,在解决UUV线型优化的过程中,引入集成优化框架,对UUV外形进行多目标优化设计;建立了UUV外形优化的一体化模型,针对UUV外形优化设计的要求,对外形设计进行参数化,提出设计变量的选取原则,并针对具体算例进行仿真优化设计,优化计算结果表明:该优化设计方法有效地改善了UUV的阻力性能和压力分布,阻力减小大约4％,在工程应用中是可行的,为目前UUV外形优化设计提供了一个完整的方法.     

大型水平轴风力机叶片气动性能优化

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.     

汽车发动机与传动系优化匹配的仿真研究

如何设计传动系参数以达到与汽车发动机的合理匹配是汽车设计中一个重要的组成部分.文中以汽车主减速比和各档传动比为设计变量,综合汽车动力性评价指标和经济性评价指标作为目标函数,建立了优化模型,应用优化规划理论对汽车传动系参数进行优化设计,开发出了一套汽车传动系参数优化设计的仿真软件,实现了汽车发动机与传动系的最佳匹配.文章最后以某载货汽车为例,利用该优化仿真软件进行了设计计算,仿真结果表明,该设计方法是可行的.     

基于多目标满意优化的计算机通信网流量和容量分配

将满意优化理论应用到计算机通信网中，提出了基于多目标满意优化的计算机通信网优化设计方法，通过设计满意度函数，构造出计算机通信网的满意优化数学模型，并用改进遗传算法实现计算机通信网的容量和流量分配的满意优化设计。仿真结果显示，所设计的网络具有更满意的综合性能指标，证实了该方法的有效性和实用性。     

2K-H型多级行星齿轮减速器优化设计系统

讨论了行星齿轮减速器设计中的穷举优化因素,以太阳轮和全部行星轮的体积之和最小为优化设计目标函数,以太阳轮的参数为设计变量,建立了优化数学模型,设计出行星轮系的优化设计系统,并以三级行星减速机为例,介绍了该系统的实际应用。     

基于运动稳定性轧管机主机头模糊优化设计

为提高轧管机主机头的运动稳定性,改善钢管的轧制质量,本文在对轧管机主机头的结构及运动状态分析的基础上,推导出主机头的运动加速度解析式,并以此为基础,建立模糊优化的数学模型。文中分别以各构件长度尺寸为设计变量,进行单变量模糊优化设计,求得各构件长度的最优取值区间,使主机头的运动稳定性得到较大的提高。本文建立的数学模型对提高轧管机的稳定性及进行优化设计提供了依据,所得出的结论为轧管机的整体优化奠定了研究基础。     

Optimum layout design of onshore wind farms considering stochastic loading

Renewable energy technologies are developing rapidly, while in the last decade great interest is encountered in the use of wind energy, especially due to the energy crisis and serious environmental problems appeared from the use of fossil fuels and therefore a large number of wind farms have been installed around the world. On the other hand the ability of nature inspired algorithms to efficiently handle combinatorial optimization problems was proved by their successful implementation in many fields of engineering sciences. In this study, a new problem formulation for the optimum layout design of onshore wind farms is presented, where the wind load is implemented using stochastic fields. For this purpose, a metaheuristic search algorithm based on a discrete variant of the harmony search method is used for solving the problem at hand. The farm layout problem is by nature a constrained optimization problem, and the contribution of the wake effects is significant; therefore, in two formulations presented in this study the influence of wind direction is also taken into account and compared with the scenario that the wake effect is ignored. The results of this study proved the applicability of the proposed formulations and the efficiency of combining metaheuristic optimization with stochastic wind loading for dealing with the problem of optimal layout design of wind farms.     

A shape optimization study for tool design in resistance welding

The purpose of this study is to apply shape optimization tools for design of resistance welding electrodes. The numerical simulation of the welding process has been performed by a simplified FEM model implemented in COMSOL. The design process is formulated as an optimization problem where the objective is to prolong the life-time of the electrodes. Welding parameters like current, time and electrode shape parameters are selected to be the design variables while constraints are chosen to ensure a high quality of the welding. Surrogate models based on a Kriging approximation has been used in order to simplify the calculation of shape sensitivities and to generate a generic tool that can be interfaced with other simulation tools. An example numerical study shows the potential of applying optimal design techniques in this area. Part of this work was presented at WCSMO7 in Seoul Korea, May 21–25, 2007, in the paper titled ‘Some optimization aspects of resistance welding’ (CD-ROM, pp 2687–2695).     

改进粒子群算法及其对热连轧机负荷分配优化的研究

提出一种基于适应度方差的权重梯度方向变异的改进粒子群优化算法（IPSO）,通过判断适应度方差,按照权重梯度方向进行变异操作,解决了PSO算法的早熟收敛和易于陷入局部极值的问题.应用IPSO算法对精轧机组负荷分配进行优化,根据负荷分配优化策略,给出综合板形板厚的最小方差目标函数,在实现各机架负荷分配优化的同时,提高板形质量.仿真结果表明,该算法计算精度高,收敛速度快,为精轧机组轧制规程的智能优化设计提供了一种新的有效方法.     

多学科目标兼容优化算法及在MEMS中应用

针对复杂系统的优化设计问题,提出了面向非层级复杂系统的多学科目标兼容优化设计方法,对其基本思路、原理进行阐述。通过在系统级中建立兼容约束和在子系统中构造兼容目标,使各子系统在独立优化设计的同时满足各系统之间的耦合关系,并使系统得到总体的最优解。并将此算法应用于梳齿式微加速度计的设计中,验证了此方法的可行性。     

面向分级设计优化的飞行器参数化建模方法

针对飞行器气动隐身外形综合设计优化问题,提出合适的面向分级设计优化流程,建立适应该流程的渐进分层参数化建模方法;用基于敏度分析的参数影响程度分析方法筛选复杂设计变量;采用多学科设计优化（Multidisplinary Design Optimization,MDO）理论和差分进化算法进行飞行器气动隐身外形的综合设计优化.将该方法用于某飞行器外形设计优化,结果表明：该方法合理可行,可为飞行器外形多学科设计优化提供一定参考.     

Eulerian shape design sensitivity analysis and optimization with a fixed grid

Conventional shape optimization based on the finite element method uses Lagrangian representation in which the finite element mesh moves according to shape change, while modern topology optimization uses Eulerian representation. In this paper, an approach to shape optimization using Eulerian representation such that the mesh distortion problem in the conventional approach can be resolved is proposed. A continuum geometric model is defined on the fixed grid of finite elements. An active set of finite elements that defines the discrete domain is determined using a procedure similar to topology optimization, in which each element has a unique shape density. The shape design parameter that is defined on the geometric model is transformed into the corresponding shape density variation of the boundary elements. Using this transformation, it has been shown that the shape design problem can be treated as a parameter design problem, which is a much easier method than the former. A detailed derivation of how the shape design velocity field can be converted into the shape density variation is presented along with sensitivity calculation. Very efficient sensitivity coefficients are calculated by integrating only those elements that belong to the structural boundary. The accuracy of the sensitivity information is compared with that derived by the finite difference method with excellent agreement. Two design optimization problems are presented to show the feasibility of the proposed design approach.