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1.
从方案论证角度,对高超声速进气道的多目标优化问题进行了分析,对马赫数6的单点工作的进气道提出了以总压恢复系数和进气道喉道马赫数为优化目标,以流量系数为约束条件,对马赫数4.5-6工作的进气道提出了以马赫数6状态的总压恢复系数和喉道马赫数为优化目标,以马赫数6状态的流量系数、马赫数4.5状态的流量系数以及马赫数4.5状态的喉道马赫数为约束条件。同时,给出了一种二维进气道参数化方法和性能计算方法。在此基础上,采用遗传算法进行优化,获得了二维进气道的多目标优化结果,结果表明采用本文方法对高超声速二维进气道进行优化设计是切实可行的。  相似文献   

2.
建立了基于试验设计理论和响应面近似的超燃冲压发动机推进的高超声速巡航飞行器多学科设计优化方法。首先建立外形尺寸、质量估算、气动力性能、气动热性能和推进性能学科的分析模型。模型考虑了学科间的耦合效应,结合弹道方程,形成了飞行器的总体性能模型。然后分别采用D—Optimal设计、Taguchi设计和均匀设计选择设计点,通过多机并行计算完成高超声速巡航飞行器性能分析。根据分析结果,构造响应面近似模型。通过响应面近似模型的优化,完成了高超声速巡航飞行器的多学科设计优化。计算表明,基于试验设计的多学科设计优化方法可以用于高超声速巡航飞行器的优化设计。  相似文献   

3.
论述了国内外高超声速进气道的最新研究动态,概括阐述了轴对称进气道、二维进气道、三维侧压式进气道和三维内收缩进气道的典型特点与性能,重点展开分析了三维内收缩进气道的设计原理与种类,包括基于流线追踪的内乘波进气道、几何变截面过渡的进气道和气动变截面过渡的进气道,介绍了该类进气道的优缺点与应用前景,最后对高超声速进气道研究应用方向进行了展望,指出三维内收缩进气道是目前新型高超声速飞行器研究与应用的热点,但其与机体一体化设计带来的内外流强耦合问题,值得深入研究。  相似文献   

4.
以时均化N-S方程为控制方程,采用变比热容的热完全气体模型和SST湍流模型,对二元混压式高超声速进气道的再起动特性进行了数值仿真。重点分析了来流马赫数、内收缩比、附面层厚度等参数对进气道再起动特性的影响,并详细分析了各因素的作用机制。研究表明,来流马赫数、内收缩比和进入进气道的附面层厚度是决定高超声速进气道再起动特性的关键因素,内收缩比较大、附面层较厚的进气道再起动迟滞回路较宽,再起动马赫数较大;附面层厚度和内收缩比决定了二元高超声速进气道不起动流场的典型特征。  相似文献   

5.
高超声速进气道是超燃冲压发动机的核心部件之一。针对几种典型的高超声速进气道设计特点、关键技术等方面进行了详细的分析和比较,重点阐述了三维内收缩进气道、高超声速曲面压缩等新技术的研究进展,并分析了高超声速进气道技术未来的研究趋势。  相似文献   

6.
王哲  李旭昌 《飞航导弹》2012,(4):79-83,87
高超声速进气道是超燃冲压发动机的关键部件,综述了国外在高超声速三维内收缩式进气道方面的研究动态,分析了包括Busemann进气道、Jaws进气道、方转椭圆式进气道及内乘波式进气道在内的几类三维内收缩式进气道的特点。对高超声速进气道研究趋势进行了展望,指出乘波前体与三维内收缩式进气道的一体化设计以及主动流动控制技术在进气道上的应用可能给未来高超声速飞行器的设计带来变革。  相似文献   

7.
建立了高超声速飞行器机体/推进系统一体化三维构型参数化模型,利用CFD数值计算开展了构型气动力的高精度数值试验并以此为基础建立了气动力响应面近似模型,以响应面近似模型作为气动力预测方法,结合遗传算法进行了高超声速飞行器三维构型的气动优化设计,获得了不同优化目标下的优化外形。  相似文献   

8.
吴则良  叶建川  王江  金忍 《兵工学报》2022,43(6):1326-1336
传统飞行器翼型参数化描述方法在翼型优化设计研究中因变量较多导致优化效率低、计算工作量大,为此提出一种基于深度自动编码器(DAE)的神经网络模型。将该模型用于翼型优化设计研究中描述参数降维问题,研究经该模型降维后各翼型描述参数的物理意义,并与本征正交分解法(POD)对翼型描述参数降维效果进行对比。在给定的优化设计目标与约束条件下,设计基于代理模型和遗传算法的翼型优化方法,对RAE2822翼型进行跨声速来流下的优化设计,将所提模型与类别形状函数变换法(CST)、POD方法的优化效率与翼型优化效果进行对比。对比结果表明,所提利用DAE神经网络模型的方法优化效率更高,在跨声速来流下对RAE2822进行减阻优化设计结果明显优于CST方法、POD方法。  相似文献   

9.
多学科设计优化中应用代理模型可以较好地解决系统分析精度和效率的矛盾,动态代理技术可以根据需要在优化的过程中不断提高代理模型精度.利用三种动态代理方法——最小响应面、最大期望提高和多点加点准则,分别对一维、二维函数和一个高维的协同优化问题中外形/气动学科构造了动态Kriging代理模型,对比了三种加点准则的动态代理效果,并分析了其特点和应用条件.结果表明,最小响应面加点准则是最适合于协同优化中学科优化的动态代理方法.  相似文献   

10.
高超声速进气道是超燃冲压发动机的关键部件之一。按照进气道结构分类,介绍了几种典型的高超声速进气道。针对现有进气道存在的主要问题,进行了简要分析和总结,重点叙述了变几何进气道的最新发展和研究成果,主要包括定几何气动调节和变几何机械调节两种类型的设计理念与方案,并对未来先进进气道的发展进行了展望。  相似文献   

11.
Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.  相似文献   

12.
The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS (geographical information system) data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.  相似文献   

13.
Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.  相似文献   

14.
By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux (kernel version 2.6.11 ) is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.  相似文献   

15.
For measuring velocity and impacting position of single fragment of warhead, a non-contact measuring method is proposed, in which a six-light-screen array, a position indicator, a multi-channel chronograph and a computer are used.The principle of measurement is described. The key device of the system is a light screen array sensor which consists of six light screens allocated with certain geometrical parameters. When the fragment flies through the light screen array, the time of passing through each of the screens is recorded by the multi-channel chronograph. According to the time data and the geometrical parameters of the array, the velocity vector and the location of the fragment can be calculated immediately. The presented method can be used to locate the fragment and to measure the real velocity on its flying direction. It can also be used to measure the velocity of a fragment swarm after the system is engineered further.  相似文献   

16.
阐述了数码电子雷管中,点火药剂细结晶三硝基间苯二酚铅(LTNR)的制备工艺;从点火药剂的种类、加入黏合剂的质量分数、桥丝直径、点火头的电阻值、防潮漆的蘸涂等方面对点火头性能的影响因素进行了探讨;通过震动试验、并联起爆试验、延期精度检测与考核,试验结果表明:一次性合成的细结晶LTNR是制造数码电子雷管点火头较为理想的点火药剂,按技术要求生产的点火头性能指标能够满足行业标准要求。  相似文献   

17.
By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.  相似文献   

18.
The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.  相似文献   

19.
Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.  相似文献   

20.
A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.  相似文献   

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