基于遗传规划和线性鉴别分析的故障特征提取模型及其应用

1引言航空发动机故障诊断需要从原始监测数据中获取合理的特征参数,如果依靠专家经验手工从众多的监测参数中选取特征参数,将是十分烦琐和低效的。因此,构造优质的特征参数是提高故障诊断效率及其准确性的关键。许多机器学习方法被应用到特征参数的自动选取中,例如神经网络[1],     

基于DRNN网络的航空发动机多变量解耦控制

通过分析对角递归神经网络（DRNN）及带动量项的梯度学习方法（GDM）,针对某型涡扇发动机的性能控制,研究了基于对角递归神经网络的多变量自学习解耦控制算法及其在航空发动机控制中的应用.阐明了该方法的结构和原理.并在设计点处进行了发动机多变量解耦控制系统设计.在偏离设计点时,大量的仿真结果表明,系统具有较好解耦和自适应能力.     

压电元件的高温、高稳定性性能研究

通过试验、分析、比较,提出了高温、高稳定性压电元件的研制要求,并确认了铋钛系列晶体是制作压电加速度传感器较理想的材料.     

基于知识管理的航空发动机设计知识分类与获取

现代航空发动机设计是基于知识的设计,知识分类与获取是航空发动机设计知识管理的起点,也是难点.实施知识获取技术能够使得设计知识有效积累,推动设计知识管理实施,从而真正实现基于知识的设计,提高航空发动机设计水平.分析了航空发动机设计过程、航空发动机结构,提出了航空发动机设计知识分类方法、知识获取策略与获取方法,进一步探讨了...     

基于特征的航空发动机涡轮叶片参数化设计

从零件层、特征层和参数层的角度,详细分析和阐述了涡轮叶片及其叶身特征、叶身附属特征和标准件之间的关系.给出了涡轮叶片的叶身特征、标准件,以及叶身附属特征中的扰流柱和隔肋特征参数化设计的实例.详细介绍了扰流柱和隔肋的参数化设计过程,以程序设计结合标准模板件的方式实现了扰流柱和隔肋的参数化设计.     

Advanced optimization of gas turbine aero-engine transient performance using linkage-learning genetic algorithm: Part I,building blocks detection and optimization in runway

This paper proposes a Linkage Learning Genetic Algorithm (LLGA) based on the messy Genetic Algorithm (mGA) to optimize the Min-Max fuel controller performance in Gas Turbine Engine (GTE). For this purpose, a GTE fuel controller Simulink model based on the Min-Max selection strategy is firstly built. Then, the objective function that considers both performance indices (response time and fuel consumption) and penalty items (fluctuation, tracking error, overspeed and acceleration/deceleration) is established to quantify the controller performance. Next, the task to optimize the fuel controller is converted to find the optimization gains combination that could minimize the objective function while satisfying constraints and limitations. In order to reduce the optimization time and to avoid trapping in the local optimums, two kinds of building block detection methods including lower fitness value method and bigger fitness value change method are proposed to determine the most important bits which have more contribution on fitness value of the chromosomes. Then the procedures to apply LLGA in controller gains tuning are specified stepwise and the optimization results in runway condition are depicted subsequently. Finally, the comparison is made between the LLGA and the simple GA in GTE controller optimization to confirm the effectiveness of the proposed approach. The results show that the LLGA method can get better solution than simple GA within the same iterations or optimization time. The extension applications of the LLGA method in other flight conditions and the complete flight mission simulation will be carried out in part II.     

后挡板结构对刷式密封泄漏特性影响实验研究

为了研究后挡板结构对刷式密封泄漏特性的影响,模拟航空发动机静态和动态工况,对三种不同后挡板结构的刷式密封泄漏特性进行实验研究。实验结果表明：相比于标准型刷式密封,后挡板结构中设计环形平衡腔能有效缓解刷式密封刷丝滞后效应,但间隙值过大将导致刷式密封性能下降;刷式密封实验件b（有环形平衡腔,与刷丝束之间的间隙为0.2mm）的泄漏参数Φ2保持在7 g﹒K1/2﹒mm/（N﹒s）以内,表现出优异的密封性能,这说明合适的环形平衡腔间隙值设计,能有效缓解刷式密封刷丝滞后现象。根据实验结果,环形平衡腔的间隙设计值应不大于0.4mm。     

基于通流程序的低速模拟气动设计及数值验证

为了验证多级轴流压气机出口级性能,开展四级重复级低速模拟气动设计,并坚持以二维设计为主,三维数值验证为辅。利用相同的设计系统,建立了高低速压气机之间相似的二维流场和叶表无量速度分布。随后,低速与高速压气机三维数值计算结果对比表明,压升系数特性吻合,流场相似,且叶表无量纲速度由设计点到失速点保持一致的变化趋势,进一步验证了二维设计的可行性;利用相同的系统设计高、低速压气机,有利于形成高速-低速-高速的良性循环,有利于完善基于通流程序的设计体系,积累设计经验。     

满足二次稳定及干扰抑制性能指标的航空发动机H∞控制器设计

对于一类状态及输出矩阵存在结构参数摄动的对象,本文提出了闭环系统满足二次稳定性及干扰抑制性能的动态输出反馈控制器的理论设计方法,随后进行的仿真结果表明,所设计的控制器满足要求。      

Electrochemical machining of complex components of aero-engines: Developments,trends, and technological advances

Because of several advantages, such as no tool wear, independence on the mechanical properties of the material, and high machining efficiency, electrochemical machining (ECM) has become a viable method for machining components in numerous industrial applications, particularly in the manufacture of typical aero-engine components with complex structures fabricated from materials that are difficult to cut. This paper highlights the current developments, new trends, and technological advances of key factors of ECM, such as electrochemical dissolution characteristics of novel difficult to cut materials which are often used in aero-engine, numerical simulation of electrochemical process, design for the complex profile and structure of cathode tool, flow field simulation and design for uniform electrolyte flow, and innovation of electrochemical machining or hybrid methods which reflect the state of the art in academic and industrial research on electrochemical machining in aero-engine manufacturing.