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一种航空发动机加速控制参数优化新方法 总被引:2,自引:0,他引:2
研究航空发动机加速控制器参数优化问题,对衡量军用飞机性能优劣起着重要作用.针对目前适用于航空发动机加速控制器参数优化的方法很少且效果不佳的问题,根据发动机非线性和时变性强的特点,采用在常规N-M单纯形非线性优化算法的基础上,结合平移误差阈值判断,引入顶点平移的改进单纯形法对PID控制器的比例、积分、微分系数进行参数优化,以调节时间与误差平方和压气机喘振裕度乘积的积分建立目标函数,寻优过程用基于CodeBlocks平台的C语言编制控制算法实现.仿真结果表明,改进方法收敛速度快,实时性好,满足发动机加速过程响应时间短,不喘振、不超温的要求. 相似文献
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开展基于主动防喘的航空发动机加速控制仿真研究。在建立航空发动机数学模型的基础上,设计了基本加速率控制、基于主动防喘的加速率控制、基于主动防喘的喘振裕度控制及基于喘振裕度估计的喘振裕度控制等4个发动机加速控制方案。仿真结果表明:①主动防喘控制可以在发动机稳定性恶化的情况下,通过较小的控制输出和性能损失实现无喘加速;②主动防喘控制与直接喘振裕度控制相结合可以简化发动机加速控制器设计,不需要额外的优化过程便能得到较优的加速性能;③主动防喘控制可以降低发动机设计点的喘振裕度,从整体上提高了发动机的性能。 相似文献
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杨妮 《CAD/CAM与制造业信息化》2017,(1)
一、引言
航空发动机的零件多为环形件,结构较复杂、精度高,尤其是很多环类零件辐板上有多组异型通孔,且孔口内外要求倒圆角,给加工提出了难题.传统方法是采用钳工手工倒圆角,劳动强度大,加工效率低且质量不稳定. 相似文献
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良好的飞机推进系统要求航空发动机在整个飞行包线范围内都必须有足够的可用稳定裕度,这就决定了航空发动机整机稳定性数值模拟的重要性.为使航空发动机整机稳定性数值模拟计算结果精确度更高,在常用的一维稳定性数值模拟计算模型中加入掺混系数,使得模型能够模拟航空发动机轴向单元体中轴向单元之间的能量交换和动量交换,且对掺混系数对数值模拟结果的影响进行分析研究.结果表明,畸变衰减主要是由风扇和压气机单元引起;风扇和压气机部件单元体的掺混系数对稳定性影响很大,压缩部件附近一般单元体掺混系数对稳定性影响有限. 相似文献
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以小波多分辨分析为理论基础,结合过程神经网络模型,建立了具有分层、多分辨和局部学习特性的多分辨小波过程神经网络.该网络充分利用小波函数和尺度函数互补的特性,以及过程神经网络可以处理连续输入信号的能力,能够很好地解决复杂的非线性时间序列的预测问题.给出了相应的学习算法,并以航空发动机排气温度裕度状态监视为例,利用多分辨小波过程神经网络进行预测.结果表明,多分辨小波过程神经网络收敛速度快、精度高.同时也为航空发动机排气温度裕度状态监视问题提供了一种有效的方法. 相似文献
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涡轮叶顶间隙数值仿真 总被引:4,自引:1,他引:3
叶顶间隙显著地影响着现代航空发动机的经济性和可靠性,叶顶间隙主动控制技术可以降低燃油消耗率的同时,保证安全性的要求.基于某型航空发动机的结构尺寸,分别建立了机匣、叶片、轮盘的数学模型.利用自行开发的叶顶间隙仿真程序,改进了叶片和涡轮盘数学模型,并与某型发动机整机的模拟程序相结合,计算了某型航空发动机高压涡轮叶顶间隙的时间历程变化.结果表明:叶顶间隙分别在慢车突然加速和反推力状态下出现最小值.叶顶间隙的计算结果基本上符合试验数据,说明该仿真程序不仅计算速度快,而且还具有足够的精度. 相似文献
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针对传统思维进化算法搜索半径缺乏目的性,临时子群体补充缺乏方向性以及神经网络训练速度慢、泛化能力不足,传统极端学习机隐含层神经元个数多的缺点,提出一种多群体自适应思维进化算法优化的极端学习机(MSMEA-ELM)算法,通过传感器数据训练该算法用于对航空发动机大范围动态过程进行辨识.以训练均方误差与权值2范数的加权和最小为优化目标,采用多群体自适应思维进化算法优化极端学习机.以某型涡扇发动机为研究对象,采用MSMEA-ELM算法进行航空发动机动态过程辨识,验证了该算法的有效性. 相似文献
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S. Nagendra J.B. Staubach A.J. Suydam S.J. Ghunakikar V.R. Akula 《Structural and Multidisciplinary Optimization》2005,29(3):213-231
The role of uncertainty in information rich design systems is critical to the development of advanced propulsion systems. Future turbine engines would have lower lifetime operating costs similar to current evolving automotive systems. Detailed multi-physics models (thermo-fluid, structural and mechanical systems) and an operational environment are enablers of rapid correction and model-based predictive analyses. Bayesian machine learning paradigms are developed to identify the behavior of turbo-machinery components for preliminary design. The embedded models approach enables systematic evolution from individual components level to the advanced engine. The embedded models approach enables systematic evolution from individual components level to the advanced engine. A rapid response strategy is proposed, for design of turbine disks by using multidisciplinary optimization and neural networks. iSIGHT optimization software is interfaced with ANSYS to find optimum designs for a given set of design boundary conditions (rpm, live rim load, thermals, etc.). The optimum designs obtained from iSIGHT for different set of design conditions are used for machine learning and design knowledge recognition using the neural network technique. The trained network is used to predict responses for design boundary conditions. Responses predicted by the neural network are validated using ANSYS. Discrete design points are chosen from the wide design space of turbine disks. A hierarchical neural network approach provides an ability to quickly train the network and predict responses (weight, stresses, burst margin, etc.) for applied design conditions. This basic building process involves four steps starting from identifying design boundary conditions to the prediction of design shape for the disk. Sensitivity-based scaling rules are developed, to accommodate different materials for the disk. The technique is developed in RAPIDDISK, which provides an optimal preliminary shape and design attributes for a turbine disk. 相似文献
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COMPUTER AIDED PRELIMINARY DESIGN FOR ROTORS 总被引:1,自引:0,他引:1
Ma Mei Zhang Li Beijing University of Aeronautics Astronautics Beijing P. R. China 《计算机辅助绘图.设计与制造(英文版)》1992,(2)
An interactive computer aided preliminary design system has been developed mainly for gasturbine engine rotors. The design system covers three parts: disks, shafts and rotor dynamics. A nu-merical optimization package called MPOP is used to minimize the weight of disks, shafts and optimizethe arrangement or stiffness of bearings for rigid or flexible rotors subjected to certain constraints ofsizes, shapes, stresses, deflections, stiffness and frequencies. Various forms of disks, shafts, rotorsand structure-analysing result curves are displayed on the screen. Designer may select, inspect or modi-fy the results interactively. The integrated design of structure, optimization, strength and rotor dynamics has improved designquality and reduced turnaround time during preliminary design phase of gas turbine engine develop-ment. As an example, a real preliminary design of an aeroengine turbine rotor is described. 相似文献
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Parameterization of the computational domain is a key step in isogeometric analysis just as mesh generation is in finite element analysis. In this paper, we study the volume parameterization problem of the multi-block computational domain in an isogeometric version, i.e., how to generate analysis-suitable parameterization of the multi-block computational domain bounded by B-spline surfaces. Firstly, we show how to find good volume parameterization of the single-block computational domain by solving a constraint optimization problem, in which the constraint condition is the injectivity sufficient conditions of B-spline volume parameterization, and the optimization term is the minimization of quadratic energy functions related to the first and second derivatives of B-spline volume parameterization. By using this method, the resulting volume parameterization has no self-intersections, and the isoparametric structure has good uniformity and orthogonality. Then we extend this method to the multi-block case, in which the continuity condition between the neighbor B-spline volumes should be added to the constraint term. The effectiveness of the proposed method is illustrated by several examples based on the three-dimensional heat conduction problem. 相似文献
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基于LPV的航空发动机鲁棒变增益控制 总被引:1,自引:0,他引:1
张弛 《计算机测量与控制》2016,24(12):17-17
随着我国现代化进程的不断加快,航天航空技术标准越来越高,对于航空发动机运转工况的鲁棒性和适应性提出了更高的要求。传统的航空发动机变增益设计步骤繁琐,不能将发动机置于整个航空器的运转去考虑设计,使发动机变增益缺乏相应的稳定性和适应性,易出现系统问题。为此,提出一般基于LPV的航空发动机鲁棒变增益控制系统,依据航空发动机结构参数,考虑到航空器在空中负载特性,计算出新的约束极点 模糊变增益,在航空器发动机工作范围连续增益,避免了传统增益切换情况,在转速控制上确定误差等因素,将非线性控制设计分解为多个线性子问题,使航空器控制系统能够沿着LPV参数轨迹保持良好的运转,保持稳定性能。仿真实验证明,提出的基于LPV的航空发动机鲁棒变增益控制系统控制效果优于传统方法,在航空器发动机转速改变时,控制精度能够满足要求 ,改变航空器负载时,有效对目标进行变增益控制。提出的控制方法对航空发动机鲁棒变增益控制问题提供了新的解决办法,具有较大应用价值。 相似文献
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搜索引擎优化策略研究 总被引:1,自引:0,他引:1
随着Internet的发展及网络资源越来越丰富,搜索引擎所起的作用也越来越大。因此搜索引擎优化作为一种可以提升网站在搜索引擎中的排名的网站优化技术,得到了广泛的关注。如何获得高的搜索引擎排名对网站特别是商务网站显得越来越重要。文章对搜索引擎优化策略进行了系统的总结,讨论了一些具体的优化方法,并对搜索引擎优化的发展前景进行了展望。 相似文献
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Evolutionary natural frequency optimization of thin plate bending vibration problems 总被引:1,自引:0,他引:1
Chongbin Zhao G. P. Steven Y. M. Xie 《Structural and Multidisciplinary Optimization》1996,11(3-4):244-251
This paper extends the evolutionary structural optimization method to the solution for maximizing the natural frequencies of bending vibration thin plates. Two kinds of constraint conditions are considered in the evolutionary structural optimization method. If the weight of a target structure is set as a constraint condition during the natural frequency optimization, the optimal structural topology can be found by removing the most ineffectively used material gradually from the initial design domain of a structure until the weight requirement is met for the target structure. However, if the specific value of a particular natural frequency is set as a constraint condition for a target structure, the optimal structural topology can be found by using a design chart. This design chart describes the evolutionary process of the structure and can be generated by the information associated with removing the most inefficiently used material gradually from the initial design domain of a structure until the minimum weight is met for maintaining the integrity of a structure. The main advantage in using the evolutionary structural optimization method lies in the fact that it is simple in concept and easy to be included into existing finite element codes. Through applying the extended evolutionary structural optimization method to the solution for the natural frequency optimization of a thin plate bending vibration problem, it has been demonstrated that the extended evolutionary structural optimization method is very useful in dealing with structural topology optimization problems. 相似文献
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针对在航空发动机气路中带电粒子的电荷信号微弱,传感器工作环境恶劣的条件下,监测航空发动机气路故障的问题,设计了一种能适应高温、高噪声等恶劣工作环境并对电荷信号灵敏监测模型,使用LabVIEW软件建立了航空发动机气路不同工况中静电信号的子V1,对信号进行采集和分析.通过对航空发动机多种工况的模拟和试验,建立了航空发动机气路故障分析系统.结果表明:该监测模型分辨率高、信噪比高、稳定性好,可稳定地监测航空发动机的多种工况,为航空发动机气路故障诊断提供可靠的依据. 相似文献
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在飞机平尾普通肋的轻量化设计过程中,采用桁架肋代替传统的腹板肋,并利用HyperWorks的OptiStruct模块对桁架肋进行详细的尺寸优化和形状优化.优化设计时以结构质量最小为目标函数,以肋缘条与斜支柱的截面参数为设计变量,以von Mises应力和临界屈曲因子为约束条件.优化后的桁架肋质量比原腹板肋约减少29%,表明采用该方法对飞机平尾结构进行轻量化设计可行. 相似文献