共查询到19条相似文献,搜索用时 812 毫秒
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目前的发电机翼型特性数值仿真方法中,由于对翼身的抖振非定常数的计算不足,影响最终结果的准确性,因此提出直驱风力发电机特性数值仿真方法研究.首先建立风力空气动力模型,作为仿真动力基础.其次确定风翼参数,计算翼身的抖振非定常数,最后在数值仿真中将翼型实现实体化生成,并根据风力空气动力模型实现数值仿真.为了验证设计的数值仿真方法的可行性,利用某地直驱风力发电机的相关参数,使用不同对比数值仿真方法和设计方法进行翼型特性数值仿真.实验结果证明设计方法的特性系数更接近实际值,在仿真中准确性较高. 相似文献
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研究飞机飞行状态优化,取决于发动机的稳定控制.影响发动机性能的是加速器的控制稳定状态.为了研究某型航空发动机加速过程及加速控制系统性能,提出了分别独立建立涡扇发动机加速控制系统的AEMSitn数学模型和涡扇发动机的AMESet数学模型,并在AMESim软件平台上对控制系统模型和发动机模型进行联合仿真的仿真研究方法.仿真研究结果表明,所建立的联合仿真模型的动静态特性良好,仿真精度高,具有较高的置信度.机械液压式加速控制器能够顺利完成发动机加速过程控制,各项参数变化符合设计要求.提出的仿真研究方法能够成功仿真涡扇发动机加速过程,可为产品的设计提供有价值的参考. 相似文献
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针对某型高超声速飞行器纵向巡航段模型对高度和速度的机动控制问题,研究并比较了采用吸气式超燃冲压发动机与火箭发动机作动力的飞行控制方法上的不同;重点分析了机体-推力耦合特性、高度-速度耦合特性以及超燃冲压发动机工作状态对飞行姿态的巨大影响;提出了油门和升降舵的协调控制方法,并进行了线性二次型控制律设计.通过仿真验证了该设计方法的有效性. 相似文献
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为实现对子母弹飞行过程的动态仿真及散布特性的科学评估,深入分析挖掘MATLAB、3DMax、OpenGL及VC+ +开发软件之间的开发功能与接口技术,设计开发了子母弹飞行三维图形显示计算机动态仿真系统,成功地实现了子母弹飞行弹道数值计算、三维实体图形显示及飞行过程动态仿真的有机结合,研究成果对同类软件的设计开发具有重要的应用参考价值. 相似文献
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针对光学测量装备在远程高速弹丸目标跟踪测量过程中存在的跟踪测量难题,对弹丸目标的运动特性、红外辐射特性进行了研究分析,采用计算机仿真飞行弹道曲线、飞行表面温度随时间的变化曲线,得到给定条件下目标辐射度随时间的变化曲线,获得了满足试验测量需求的弹丸目标特性;通过仿真测量和半实物仿真测量等方式将研究成果应用于试验工程,在弹丸测量方案制定、装备跟踪性能评估等方面发挥重要作用,提高了试验成功率;研究成果可推广应用于其他类型目标的测试测量试验,具有较好的实用价值. 相似文献
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计算机辅助设计(CAD)在设计企业中已经得到广泛应用,有效解决了设计效率的问题,例如利用参数化设计,可以对设计进行轻松修改。而工程仿真,也叫做计算机辅助工程(CAE),可以用数值方法模拟设计对象的功能特性,从而完全或部分代替物理样机或试验验证,并引导更优化的设计。 相似文献
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关于冲压发动机动力性能优化建模问题,冲压发动机模型及特性与飞行高度、马赫数、攻角有关,决定发动机的性能因素。为了优化冲压发动机动力性能和控制系统设计总体规划,提出建立亚燃冲压发动机特性计算的数学模型,借助于simu-link仿真平台搭建了亚燃冲压发动机模块化的稳态仿真模型,进行不同飞行条件下的特性计算的分析,重点分析了不同进口条件对进气道正激波强度的影响。通过与GasTurb软件中模型参数比较验证了模型的正确性。仿真结果表明,模型可用于冲压发动机总体初步设计研究。 相似文献
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When supervising aircraft, air traffic controllers need to know the current wind magnitude and direction since they impact every flying vessel. The wind may accelerate or slow down an aircraft, depending on its relative direction to the wind. Considering several aircraft flying in the same geographical area, one can observe how the ground speed depends on the direction followed by the aircraft. If a sufficient amount of trajectory data is available, approximately sinusoidal shapes emerge when plotting the ground speeds. These patterns characterize the wind in the observed area. After visualizing this phenomenon on recorded radar data, we propose an analytical method based on a least squares approximation to retrieve the wind direction and magnitude from the trajectories of several aircraft flying in different directions. After some preliminary tests for which the use of the algorithm is discussed, we propose an interactive procedure to extract the wind from trajectory data. In this procedure, a human operator selects appropriate subsets of radar data, performs automatic and/or manual curve fitting to extract the wind, and validates the resulting wind estimates. The operators can also assess the wind stability in time, and validate or invalidate their previous choices concerning the time interval used to filter the input data.The wind resulting from the least squares approximation is compared with two other sources – the wind data provided by Météo-France and the wind computed from on-board aircraft parameters – showing the good performance of our algorithm. The interactive procedure received positive feedback from air traffic controllers, which is reported in this paper. 相似文献
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Modern automotive engines are controlled by an electronic control unit (ECU), and engine power performance is significantly affected by the selection of both ECU parameters and engine components. The engine performance tuning is usually done by a trial-and-error method. In the current literature, very little research has considered the selection of engine parts because engine parts are complicated objects that are usually represented as nominal data. These data are meaningless values in terms of computation. This paper presents a novel multiple-input/output least-squares support vector machine plus one-of-n remapping method for modelling engine power performance using both numerical (ECU parameters) and nominal data (candidate engine parts). The Quasi-Newton method, a genetic algorithm and particle swarm optimisation are then applied to the engine model to determine the optimal engine setup automatically. A simple binary code synthesis rule is also proposed to optimise the nominal variable. Both experimental and simulation results show that the proposed methodology can successfully yield an optimal engine setup. 相似文献
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针对一类三维高超声速飞行器构型,给出了刚体飞行器六自由度模型综合建模法.采用斜激波与Prandtl-Meyer膨胀波关系式等空气动力学理论,计算飞行器机身表面的气动力、控制面受力及推力.采用逐步回归的曲线拟合方法,建立了飞行器面向控制的曲线拟合模型,并分析了六自由度模型的动态特性.结果表明,曲线拟合模型降低了机理推导模型的复杂度,并保留了气动与推进系统的耦合性,为飞行器控制器设计提供依据. 相似文献
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Sidonie Lefebvre Stéphanie Allassonnière Jérémie Jakubowicz Thomas Lasne Eric Moulines 《Machine Vision and Applications》2013,24(1):175-186
Existing computer simulations of aircraft infrared signature (IRS) do not account for dispersion induced by uncertainty on input parameters, such as aircraft aspect angles and meteorological conditions. As a result, they are of little use to quantify the detection performance of IR optronic systems: in this case, the scenario encompasses a lot of possible situations that must indeed be considered, but cannot be individually simulated. In this paper, we focus on low resolution infrared sensors and we propose a methodological approach for predicting simulated IRS dispersion of an aircraft, and performing a classification of different aircraft on the resulting set of low resolution infrared images. It is based on a quasi-Monte Carlo survey of the code output dispersion, and on a maximum likelihood classification taking advantage of Bayesian dense deformable template models estimation. This method is illustrated in a typical scenario, i.e., a daylight air-to-ground full-frontal attack by a generic combat aircraft flying at low altitude, over a database of 30,000 simulated aircraft images. Assuming a spatially white noise background model, classification performance is very promising, and appears to be more accurate than more classical state of the art techniques (such as kernel-based support vector classifiers). 相似文献
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A computational method to predict transition lines for general three-dimensional configurations is presented. The method consists of a coupled program system including a 3D Navier-Stokes solver, a transition module, a boundary layer code and a stability code. The newly developed transition module has been adapted to be used with parallel computation to account for the high computational demand for three-dimensional configurations. Detailed computations have been performed to show the ability of the Navier-Stokes code to provide three-dimensional boundary layer data of high accuracy needed for the stability analysis. A comprehensive investigation on general computational and parallel performance identifies the numerical effort for the transition prediction method. The procedure has been validated comparing the numerical results with experiments for the flow around an inclined prolate spheroid. Feasibility studies on generic transport aircraft have been performed to show the code’s capability to predict transition lines on general complex geometries. 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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This paper describes the moving window parameter adaptive control system developed for the NASA F8-DFBW aircraft. The control system employs a parameter identification process that, iteratively, adjusts parameters of a model of the aircraft motions in a batch-processing manner so that responses generated from the model fit the outputs of sensors stored in a finite record referred to as the moving window. Tests are made on the validity of the parameter estimates before using the parameters in an on-line design process. The on-line design process is an algebraic mapping of the parameters of the model into primary control system feedback and feedforward gains. The mapping was selected to satisfy specific flying quality characteristics over the range of parameter variations expected. Results are presented from simulation studies on the identification algorithm made during the development of the system. Also, results from the F8-DFBW project simulation at the NASA langley Research Center are presented that indicate the overall performance of the control system in meeting the flying quality objectives of the design. 相似文献
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Multiple parts in gas exchange system of 2-stroke heavy fuel aircraft engine with poppet valves lead to complicated manufacturing and inefficient assembly. Besides, real experimental optimization wastes lots of time and cost due to the increased valve parameters. To address the above issues, the paper proposes a digital twin (DT)-driven optimization method with several DT modules for the system to virtually simulate and optimize the parameters, performance and manufacturing with data interaction and recorded. The DT modules receive real-time feedback data from manufacturing measurements and performance tests to conduct the correction throughout the optimization process. The results demonstrate that the virtual engine model with feedback and correction is quite precise and credible compared with test results, and iterative calculation for optimal parameters is performed efficiently. With the guidance of virtual manufacturing, real manufacturing and assembly are arranged more reasonably and efficiency has been promoted. Real-world test found both power and gas exchange performance improved about 4% under various engine speeds and loads, which verified the effectiveness of DT-driven optimization. The study achieves the integration between virtual and real worlds of the system performance and manufacturing, which facilitates the development of aircraft engine smart manufacturing. 相似文献