叉型摇臂双气门配气机构的有限元分析

针对叉型摇臂双气门配气机构，对摇臂采用非协调３维等参单元进行静力分析。计算了摇臂刚度、转动惯量及摇臂刚度随转角的变化情况。在摇臂静力分析的基础上，建立了整个机构的有限元动力分析模型，用Ｗｉｌｓｏｎ－逐步积分方法求解动力分析方程；并对２３０柴油机配气机构进行了有限元动力分析，计算了机构的主要参数，实测了气门加速度。其计算结果和实测结果基本一致。     

叉型摇臂双气门配气机构有限元分析

针对叉型臂双气门配气机构，对摇臂采用非协调３维等参单元进行静力分析。计算了摇臂刚度、传动惯量及摇臂刚度随转角的变化情况。在摇臂静力分析的基础上，建立了整个机构的有限元动力分析模型，用Ｗｉｌｓｏｎ－θ逐步积分方法求解动力分析方程；并对２３０柴油机配气机构进行了有限元动力分析，计算了机构的主要参数，实测了气门加速度。其计算结果和实测结果基本一致。     

重载柴油机气缸套变形分析及结构参数优化

简要分析了某重载柴油机的钢制薄壁顶置湿式气缸套在装配和使用过程中出现变形超差的影响因素。建立了由机体、气缸盖、气缸垫、机体螺栓、气缸套组成的组合结构有限元分析模型，利用多方案数值计算方法研究装配使用过程中气缸套变形机理及结构敏感部位参数，以便对改进设计提供理论指导和依据。优选的气缸套参数已用于某重载柴油机演示验证样机的气缸套结构设计改进。     

25.2 L柴油机摇臂的仿真分析与优化

为了分析某25.2 L柴油机摇臂断裂的原因，借助Abaqus和FEMFAT有限元分析软件，对柴油机摇臂组件在运行工况下的结构应力及高周疲劳进行分析，并对摇臂危险区域进行优化后再次进行仿真分析，直到摇臂满足设计要求。结果表明：考虑装配过盈力时摇臂的峰值应力比未考虑过盈力时高10.6%，考虑装配过盈力时仿真结果与试验结果相吻合；直角卸油槽为摇臂局部薄弱区域，使用圆弧形卸油槽代替直角卸油槽能有效降低局部应力集中；优化后摇臂峰值应力降低17.5%，摇臂抗疲劳性能得到提升。     

有限元弹性动力分析与优化在某气门机构中的应用

对某发动机气门机构建立了混合刚体-弹性体的参数化非线性有限元模型,进行了弹性动力学计算。通过回归方程对模型进行了优化,降低了摇臂的质量,在保证摇臂强度的同时改善了凸轮-滚子的接触性能,从而降低了磨损,提高了耐久性。     

军用柴油机曲轴的动态仿真研究

为了设计出具有更良好性能的军用柴油机，本文以某军用柴油机曲轴为例，对曲轴进行了动态仿真研究。在曲轴有限元模型上施加模拟实际工作状态的边界约束和载荷条件，利用振型叠加法对其进行动态响应分析，并与设计指标对比，对原曲轴结构参数进行了动力修改。为避免结构修改的盲目性，采用了灵敏度分析方法，计算出曲轴的动态特性参数随设计变量的变化灵敏度，选择那些对动态特性影响较大的设计参数作为修改参数，通过上述方法修改后的曲轴，动态响应结果能够满足给定的设计指标，使得曲轴的结构达到了最优，为整机的动力学仿真研究奠定了基础。     

某柴油机机体结构强度计算分析

利用有限元软件对某柴油机机体结构进行计算分析,并通过疲劳软件计算出结构的疲劳安全系数。通过有限元计算来模拟机体疲劳试验,分析结构是否满足设计要求,为设计提供参考。     

柴油机组合结构的参数化建模及应用

应用特征技术和动态子结构法建立了某柴油机机体＋曲轴组合结构的参数化实体模型，并用有限元模态分析法进行模态参数的计算。计算出前五阶固有频率和主振型，与试验结果吻合，说明所建机体＋曲轴组合结构的参数化模型正确，为其下一步的动力学仿真研究奠定了基础。     

基于midas NFX某游乐设备的结构分析设计

游乐设备作为事关大众的特种设备，引入有限元分析可以最大程度保证设计的安全可靠，为游乐设施的开发开辟了新篇章。本文利用著名的全中文有限元分析软件midas NFX对某型游乐设备进行详细的设计计算，考虑各种载荷自重、离心力、风载、地震载荷等及组合，模拟运行和非运行状态下的受力，并计算出结果。结果表明设计结构符合设计要求，有限元在游乐设备中应用更方便，分析结果更全面，更适合于象游乐设备此类特种设备的分析计算。     

三相GIS母线参数有限元计算方法研究

摘要： GIS母线的电阻、电感、电容是GIS设计及电力系统分析中必不可少的参数,由于集肤效应和临近效应的存在,给三相GIS母线参数的计算带来了很大的困难。在综合考虑集肤效应和临近效应等因素影响的基础上,建立了基于能量角度计算三相GIS母线参数的电磁场有限元模型,计算了不同对称性条件、不同频率下的三相GIS母线参数。结果表明：三相GIS母线参数有限元计算方法精度高;该计算方法不受GIS结构的影响,具有很好的灵活性。     

集群光伏电站一次调频参数经济优化设计方法

针对集群光伏电站参与电网一次调频,提出一种可实现光伏电站经济性最优的一次调频下垂参数优化设计方法.通过模拟同步发电机一次调频的下垂控制,设计考虑减载率与左右下垂系数3个参数的光伏集群参与一次调频的控制方案.在建立单一光伏电站调频参数优化模型的基础上,通过K均值聚类实现光伏集群规模化一次调频参数的降维优化设计.最后,以5...     

太阳能会聚器的优化设计

讨论了用光学设计软件CODE V对太阳能会聚器进行优化设计的问题。在描述了太阳能会聚器的主要设计参数后，我们分析了抛物型会聚器的特性。利用光学设计软件，设计出一类新的高次非球面会聚器。实验结果表明，此类会聚器可实行间断跟踪太阳，且接收面光能量分布均匀，提高了系统转换效率，还具有节约能量、降低成本等优点。     

风电场中电力无源滤波器设计与优化

研究风电场并网给电网带来的谐波,分析风电场产生谐波的原理和危害,介绍含风电场的电网谐波分析方法。主要研究风电场中电力无源滤波器的设计和优化方法,基于MATLAB优化工具箱设计并优化滤波器参数。对算例进行谐波分析,初步设计、选择无源滤波器参数,优化初选参数,对比加装滤波器前、加装初选滤波器和加装优化滤波器三种情况下的谐波。结果显示谐波相关指标均得到改善,且滤波效果较好。     

Global Search of a Three-dimensional Low Solidity Circular Cascade Diffuser for Centrifugal Blowers by Meta-model Assisted Optimization

A three-dimensional blade of a low solidity circular cascade diffuser in centrifugal blowers is designed by means of a multi-point optimization technique. The optimization aims at improving static pressure coefficient at a design point and at a small flow rate condition. Moreover, a clear definition of secondary flow expressed by positive radial velocity at hub side is taken into consideration in constraints. The number of design parameters for three-dimensional blade reaches to 10 in this study, such as a radial gap, a radial chord length and mean camber angle distribution of the LSD blade with five control points, control point between hub and shroud with two design freedom. Optimization results show clear Pareto front and selected optimum design shows good improvement of pressure rise in diffuser at small flow rate conditions. It is found that three-dimensional blade has advantage to stabilize the secondary flow effect with improving pressure recovery of the low solidity circular cascade diffuser.     

Single- and Multi-Objective Design Optimization of Plate-Fin Heat Exchangers Using Jaya Algorithm

This paper explores the use of Jaya algorithm for the single- and multi-objective design optimization of plate-fin heat exchangers (PFHEs). Design of PFHEs involves a number of geometric and physical parameters with high complexity. The general design approaches are based on trial and error and become tedious and time consuming and do not guarantee the achievement of an optimal design. Therefore, advanced optimization algorithms are preferred. The Jaya algorithm is a newly developed simple algorithm and it does not have any algorithmic-specific parameters to be tuned and this aspect reduces the designer's effort in tuning the parameters to arrive at the optimum value of the objective function. The Jaya algorithm is proposed for the design optimization of PFHEs by minimizing the total surface area of heat transfer, total annual cost, and total pressure drop of the system and maximizing the effectiveness. Seven design parameters are considered which are imposed by constraints on the design. Single- as well as multi-objective design optimization is carried out using the proposed algorithm. The results obtained by Jaya algorithm are compared with the results of latest reported algorithms. These comparisons revealed that the Jaya algorithm can be successfully applied for the design optimization of PFHEs.     

基于MATLAB的配气凸轮优化设计

建立了七次多项式动力凸轮型线的优化设计数学模型;利用MATLAB及其优化工具箱(Optimization Toolbox)对此问题设计程序求解。并以具体的某配气系统为例,进行优化求解,结果表明,优化后凸轮的特性参数更佳。     

柴油/天然气发动机燃烧系统协同优化方法

采用KIVA-3V软件耦合多目标遗传优化算法NSGA-3,开展了柴油/天然气双燃料发动机的引燃柴油喷射参数、运行参数和燃烧室结构参数的协同优化研究.将湍流火焰速度封闭模型(TFSC)与PaSR燃烧模型耦合,建立柴油/天然气双燃料发动机复合燃烧模型.结果表明:复合燃烧模型能较好地模拟柴油/天然气发动机的燃烧过程;采用KIVA3V-NSGA3程序进行了双燃料发动机运行参数、喷射参数等多目标参数的协同优化;多目标参数优化结果的数据对比分析揭示了设计参数对目标参数的影响规律;涡流比和喷射参数的变化会对燃烧室内温度、NOx和CH4的分布产生较大影响.     

Toward the optimization of operating conditions for hydrogen polymer electrolyte fuel cells

A study is performed to find the optimal operating conditions of hydrogen polymer electrolyte fuel cells using an efficient optimization approach based on validated multi-resolution fuel cell simulation tool developed in house. Through the design of experiment method, a set of designed simulation runs were carried out using the fuel cell simulation tool. Based on the simulation results, an analytic metamodel was then constructed using the radial basis function approach. A feasible sequential quadratic programming scheme was then employed to optimize the metamodel to achieve the global optimal solutions. To illustrate the optimization approach, four control parameters including cell temperature, cathode stoichiometry, cathode pressure, and cathode relative humidity were considered. The optimization objective is defined as the maximization of the overall efficiency of the fuel cell system under ideal or realistic system assumptions. The study shows that different optimal solutions exist for different system assumptions, as well as different current loading levels, classified into small, medium, and large current densities. The approach adopted in this study is generic and can be readily applied to a larger number of control parameters and further to the fuel cell design optimizations.     

Site‐specific Design Optimization of Wind Turbines

This article reports results from a European project, where site characteristics were incorporated into the design process of wind turbines, to enable site‐specific design. Two wind turbines of different concept were investigated at six different sites comprising normal flat terrain, offshore and complex terrain wind farms. Design tools based on numerical optimization and aeroelastic calculations were combined with a cost model to allow optimization for minimum cost of energy. Different scenarios were optimized ranging from modifications of selected individual components to the complete design of a new wind turbine. Both annual energy yield and design‐determining loads depended on site characteristics, and this represented a potential for site‐specific design. The maximum variation in annual energy yield was 37% and the maximum variation in blade root fatigue loads was 62%. Optimized site‐specific designs showed reductions in cost of energy by up to 15% achieved from an increase in annual energy yield and a reduction in manufacturing costs. The greatest benefits were found at sites with low mean wind speed and low turbulence. Site‐specific design was not able to offset the intrinsic economic advantage of high‐wind‐speed sites. It was not possible to design a single wind turbine for all wind climates investigated, since the differences in the design loads were too large. Multiple‐site wind turbines should be designed for generic wind conditions, which cover wind parameters encountered at flat terrain sites with a high mean wind speed. Site‐specific wind turbines should be designed for low‐mean‐wind‐speed sites and complex terrain. Copyright © 2002 John Wiley & Sons, Ltd.     

基于叶轮子午面田口试验的潜水泵水力优化设计

为探究叶轮子午面型线变化对潜水泵水力性能的影响规律,利用田口试验设计与数值计算相结合的方法,以扬程、效率作为优化目标,选取出口段中点位置、倾斜角及前、后盖板交线出口角等8个参数为变量因子,基于田口设计L27（313）表设计出27组方案,采用效应分析法对计算结果进行分析并确定参数间的主次顺序,最终确定出了性能最佳的参数组合方案。结果表明,在叶轮子午面型线设计中,前、后盖板交线的变化是影响潜水泵水力性能的关键。优化后模型的水力性能得到了较大提升,为后续潜水泵叶轮水力设计的研究提供了参考。