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弯体机动再入飞行器气动特性研究 总被引:7,自引:6,他引:7
本文计算和分析了弯体机动再入飞行器的高超声速纵横向气动特性。研究了质心布置对配平、配平升阻经的影响规律,给出了三个方向稳定配平的必要充分条件。通过气动力与六自由度弹道的耦合,模拟了弯体飞行器螺旋机动飞行时的弹道特性,指出了质心的运动规律应根据需要预先给出。 相似文献
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再入机动飞行器的控制系统设计 总被引:1,自引:0,他引:1
基于再人机动飞行器机动控制特点,设计了两种反馈结构——过载反馈和姿态角反馈的姿控系统.并从输入反馈信号构成、系统回路设计、反馈系数确定及飞行弹道仿真结果等方面,对两种形式的姿控系统进行了比较。结果表明.过载反馈系统在再人机动飞行器的飞行控制中效果较好。 相似文献
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空战智能决策将极大改变未来战争的形态与模式。深度强化学习决策机可以挖掘飞行器潜力,是实现空战智能决策的重要技术范式,但其工程实现鲜有报道。针对基于深度强化学习的双机近距空战机动智能决策的工程实现问题,开发了适于应用的深度神经网络在线机动决策模型,发展了通过飞行控制律跟踪航迹导引决策指令的机动控制方案,并进一步开展了软硬件实现工作与人机对抗飞行试验,实现了智能空战从虚拟仿真到真实飞行的迁移。研究结果表明基于本文发展的近距空战机动决策及控制方法,智能无人机在与人类“飞行员”的对抗中能够迅速做出有利于己方的动作决策,通过机动快速占据态势优势。研究结果显示了深度神经网络智能决策技术在空战决策中的潜在应用价值。 相似文献
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智能蒙皮飞行器的飞行控制研究 总被引:5,自引:0,他引:5
将嵌入大量微致动器元件的智能蒙皮应用于飞行器,以增强或替代传统的控制面来产生控制力矩,使飞行器稳定并能进行机动飞行。以无尾飞行器为例,推导了其动力学模型,并设计了状态反馈控制器。仿真结果表明,所讨论的智能蒙皮对机动要求不大的无尾飞行器具有足够的控制能力。 相似文献
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飞行器在大迎角下机动飞行,流动状态的非定常性是其重要特性。对飞行器的非定常气动特性研究预测,主要还是以风洞试验为主。以前风洞试验主要是动导数试验和大迎角非定常试验。由于这两种试验的局限性,AEDC最近开始研究一种新的风洞试验技术一虚拟飞行试验技术。本文主要是对这种新的风洞试验技术研究情况做了介绍。 相似文献
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高机动导弹气动/运动/控制耦合的风洞虚拟飞行试验技术 总被引:2,自引:0,他引:2
解决先进飞行器大迎角高机动飞行时的气动/运动非线性耦合问题,需要发展基于非线性理论的风洞试验技术,即风洞虚拟飞行试验技术。该试验能够实现较为逼真的模拟飞行器机动运动过程,气动和运动参数的实时同步测量,以及飞行控制律的集成验证与优化,从而达到探索气动/运动耦合特性和机理的目的。本文介绍了风洞虚拟飞行试验的模拟方法、关键技术及其解决措施,并针对典型导弹模型开展了虚拟飞行验证试验。试验结果表明:目前已经初步具备适用于导弹模型跨声速气动/运动/飞行控制一体化研究的风洞虚拟飞行试验能力。 相似文献
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机动飞行飞行器内具有初始弯曲和刚度不对称的转子运动模型 总被引:1,自引:1,他引:1
本文建立了位于机动飞行飞行器内且同时具有初始弯曲、不对称刚度和质量不平衡的单盘Jeffcott转子的动力学模型。当飞行器静止时,设相关参数为零后该模型与相应地面转子系统的数学模型完全相同。应用该模型可数值仿真研究飞行器运动时位于飞行器内的等转速、等加速、等减速运行转子的动态特性,研究飞行器不同飞行速度和加速度对转子动力学特性的影响,分析飞行器飞行时转子出现故障时的响应特性,从而为机动飞行器内转子的动力学分析和故障诊断提供依据。 相似文献
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NING Guo-dong ZHANG Shu-guang FANG Zhen-ping 《中国航空学报》2007,20(1):1-8
A method for the implementation of integrated three-degree-of-freedom constrained entry guidance for reusable launch vehicle is presented. Given any feasible entry conditions, terminal area energy management interface conditions, and the reference trajectory generated onboard then, the method can generate a longitudinal guidance profile rapidly, featuring linear quadratic regular method and a proportional-integral-derivative tracking law with time-varying gains, which satisfies all the entry corridor constraints and meets the requirements with high precision. Afterwards, by utilizing special features of crossrange parameter, establishing bank-reversal corridor, and determining bank-reversals according to dynamically adjusted method, the algorithm enables the lateral entry guidance system to fly a wide range of missions and provides reliable and good performance in the presence of significant aerodynamic modeling uncertainty. Fast trajectory guidance profiles and simulations with a reusable launch vehicle model for various missions and aerodynamic uncertain-ties are presented to demonstrate the capacity and reliability of this method. 相似文献
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基于飞机油箱模型形状特征油量测量切片步长选择方法研究 总被引:1,自引:0,他引:1
在分析飞机数字式油量测量过程中目前广泛使用的切片法油量测量原理的基础上,针对现有的定步长切片法无法得到准确、可靠的燃油质量特性数据库的缺陷,结合对飞机油箱模型形状特征的分析,提出了基于飞机油箱模型形状特征的油量测量切片步长选择方法。此方法包括切片步长整体和局部选择两个过程,整体选择以实现相邻两切片平面所夹油箱模型体积近似相等为目的来确定切片步长,以体现油箱模型截面整体变化规律;局部选择以设计切片平面与截面突变平面重合或尽可能接近的方式,突出油箱截面的局部变化特征。实验结果表明:该切片步长选择方法较定步长方法能够建立更为合理、可靠的燃油质量特性数据库,从而提高了油量测量精度。 相似文献
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The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow 总被引:1,自引:0,他引:1
This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation. 相似文献
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Abnormal Shape Mould Winding 总被引:1,自引:0,他引:1
Fu Hongya Wang Xianfeng Han Zhenyu Fu Yunzhong 《中国航空学报》2007,20(6):552-558
为解决网格化芯模的缠绕问题,本文提出了复合材料面片缠绕机理;接着详细分析了面片缠绕过程中的芯模凹曲面上纤维滑线和架空现象,应用微分几何曲面理论和空间几何理论,提出判据及其解决方案;最后,针对飞机发动机进气道的缠绕成型,编制缠绕控制程序并进行相应的实验,验证了面片缠绕方法的可行性。 相似文献
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FU Hong-jun MA Chong-qi KUANG Nai-hang LUAN Shi-lin 《中国航空学报》2007,20(2):124-128
This work was dedicated to performing surface oxidation and coating treatments on carbon fibers (CF) and investigating the changes of fiber surface properties after these treatments, including surface composition, relative volume of functional groups, and sur- face topography with X-ray photoelectron spectroscopy (XPS) and atom force microscopy (AFM) technology. The results show that, after oxidation treatments, interfacial properties between CF and non-polar polyarylacetylene (PAA) resin are remarkably modified by removing weak surface layers and increasing fiber surface roughness. Coating treatment by high char phenolic resin solution after oxida- tion makes interface of CF/PAA composites to be upgraded and the interfacial properties further bettered. 相似文献
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Xu Chenghai Meng Songhe Zhang Mingfu Zuo Hongbo Wang Guigen 《中国航空学报》2007,20(5):475-480
本文利用有限元法对冷心放肩微量提拉法(SAPMAC)生长大尺寸蓝宝石单晶过程中的热应力进行了模拟计算,应用临界缺陷理论解释了裂纹的萌生与扩展机理。研究表明,晶体内的热应力主要与晶体生长速率,环境温度和结晶取向有关;较大热应力多出现在结晶界面,放肩、收尾以及直径急剧变化等位置;最大热应力总是出现在籽晶与新生晶体的界面附近。裂纹将在临界缺陷位置产生,并在应力作用下沿a或m面扩展。计算结果与实验结果基本吻合,通过晶体生长系统和生长工艺的改进,对晶体的开裂问题得到了有效的抑制。 相似文献
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CHENG Wen-yuan CHANG Yan CUI De-gang XIE Xiang-hui 《中国航空学报》2007,20(1):55-59
To solve the topology optimization of complicated multi-objective continuous/discrete design variables in aircmit structure design, a Parallel Pareto Genetic Algorithm (PPGA) is presented based on grid platform in this paper. In the algorithm, the commercial finite element analysis (FEA) software is integrated as the calculating tool for analyzing the objective functions and the filter of Pareto solution set based on weight information is introduced to deal with the relationships among all objectives. Grid technology is utilized in PPGA to realize the distributed computations and the user interface is developed to realize the job submission and job management locally/remotely. Taking the aero-elastic tailoring of a composite wing for optimization as an example, a set of Pareto solutions are obtained for the decision-maker. The numerical results show that the aileron reversal problem can be solved by adding the limited skin weight in this system. The algorithm can be used to solve complicated topology optimization for composite structures in engineering and the computation efficiency can be improved greatly by using the grid platform that aggregates numerous idle resources. 相似文献