旋流式掺混结构对补燃室二次燃烧性能的影响

文中设计了两种新型旋流式固冲发动机补燃室掺混结构,对该掺混结构作用下补燃室掺混燃烧流场进行了数值研究.分析了旋流式掺混结构对补燃室中掺混燃烧的影响,并与两种基准补燃室掺混结构的计算结果进行了对比分析.结果表明:旋流式掺混结构能够强化补燃室中的掺混燃烧效果,大幅提升固冲发动机补燃室的特征速度,且补燃室总压恢复系数满足设计需求,但补燃室内的旋流流动在一定程度上会削弱冲压喷管的做功能力.     

高温燃气射流对固冲发动机二次燃烧效率影响研究

为进一步提高固冲发动机的二次燃烧效率,文中提出了在固冲发动机补燃室头部引入高温燃气射流增强掺混燃烧的技术思路,并开展了仿真和验证试验工作。仿真分析表明：当在补燃室头部引入高温燃气射流时,能够提高补燃室头部流场的温度,使得燃料更易于燃烧,从而提高了固冲发动机的二次燃烧效率;试验结果也验证了在固冲发动机头部引入高温燃气射流,能够使固冲发动机的二次燃烧效率由81.3％提高到88.7％。     

进气道直径大小对固冲发动机内流场的影响研究

为了探索在一定补燃室长度条件下进气道直径大小对固冲发动机内流场的影响,采用了标准k-ε湍流模型和组分输运模型数值模拟了一设计的固冲火箭发动机掺混燃烧过程的内流场。结果表明:在一定补燃室长度和进出口条件下,存在一最佳进气道直径,能使空气与燃气完全掺混燃烧。在文中模拟条件下的最佳进气道直径为30mm。     

固冲发动机补燃室流场条件下硼燃烧试验研究

建立了一套固冲发动机地面模拟试验系统,用于研究补燃室流场条件下硼的燃烧,该试验系统用乙醇与氧气反应加热硼颗粒,并与空气二次燃烧的方式,模拟含硼固冲发动机的工作过程,其一次燃烧产物主要为H2、CO和硼颗粒,补燃室总温、静温值为1300~1400K,总压、静压值为0.4~0.5MPa,马赫数值为0.35左右,与真实固冲发动机相关参数值相符合。基于此试验系统,采集了燃气发生器、补燃室进气口、掺混区、燃烧区和喷管等位置的凝相燃烧产物。扫描电镜(SEM)、X射线衍射(XRD)和X射线能谱(EDS)分析结果表明,硼在反应过程中呈颗粒状,整体形貌变化不太明显,大部分的硼在补燃室中完成反应,燃烧区硼的反应量最大,靠近喷管区域次之,掺混区域最少。     

某两侧进气固冲发动机二次燃烧性能提升仿真研究

为了提高采用头部两侧进气布局形式的固冲发动机的二次燃烧性能,以某地面连管试验用固冲发动机为研究对象,分别从进气道出口形式和燃气喷射方式两个方面对补燃室掺混燃烧流场的影响进行了仿真研究.结果表明:进气道出口结构形式对该种布局方案的补燃室二次燃烧性能有重大影响;在保持进气道出口结构不变的条件下通过合理配置一次燃气喷射方式可以在一定程度上提升二次燃烧性能.     

二元空气进口结构参数对固冲补燃室掺混燃烧性能的影响

采用试验设计方法,基于双侧水平二元空气进气布局固冲发动机,针对固冲补燃室空气进口长宽比和空气进气面积这两种因素对固冲补燃室掺混燃烧性能的影响进行仿真分析。结果表明:空气进口长宽比和进气面积对补燃室掺混燃烧性能的影响较大,且在特定水平下两因素对补燃室掺混燃烧性能的影响存在交互作用;随着空气进口长宽比的增大,补燃室温升效率呈先基本恒定、然后减小、再增大的趋势,而补燃室总压恢复系数均呈减小的趋势;当空气进口长宽比大于1.000时,空气进气面积较小时补燃室温升效率相对较高;相同空气进口长宽比时,空气进气面积较小时的补燃室总压恢复系数均相对较高。     

含硼固冲补燃室燃烧组织技术进展

含硼固冲发动机是新一代超声速导弹的理想动力系统,但由于点火时间长、燃烧速率慢,硼的高热值不易获得。如何实现补燃室的高效燃烧一直是含硼固冲发动机研究热点。本文基于国内外的研究成果,论述了补燃室内单颗粒硼/碳点火燃烧过程与机理,影响规律及促进方法;评述了两相掺混燃烧过程数值模拟和试验的研究进展;总结了含硼固冲补燃室燃烧组织规律。对目前研究中存在的问题与不足进行了总结,对未来发展方向和研究重点进行了展望。     

环向进气固体火箭冲压发动机补燃室流场数值模拟

文中采用标准κ-ε双方程湍流模型数值模拟一种环向进气的固体火箭冲压发动机补燃室的掺混燃烧过程．考虑了补燃室的出口反压、空燃比和燃气喷射角度等设计参数对燃烧流场的影响．结果表明：增大出口反压和空燃比．有利于补燃室内掺混和燃烧的进行;增大燃气喷射角度．补燃室头部温度升高,燃料停留时间增大,对燃烧流场特性影响不大。     

某两侧进气固冲发动机补燃室沉积研究

采用纯气相燃烧模型对某两侧进气固冲发动机补燃室内流场进行了数值模拟,根据流线图对补燃室内的沉积分布进行了预测,并与试验结果进行了对比。结果表明,该构型固冲发动机补燃室内的沉积主要集中在进气道对称平面的补燃室壁面及冲压喷管收敛段,补燃室头部也有部分沉积;补燃室内的沉积包括一次燃烧产物中未燃烧完全的凝相粒子和二次燃烧产物冷凝形成的凝相粒子;采用纯气相模拟可以对该构型的补燃室沉积分布情况进行定性预测。     

补燃室头部距离对固冲发动机二次燃烧的影响

补燃室头部距离是影响固体火箭冲压发动机二次燃烧效率的关键参数,采用数值模拟的方法研究分析了该参数对固体火箭冲压发动机二次燃烧效率的影响,数值结果与同等条件下实验结果的对比分析表明：补燃室头部距离的增大,可增大头部的漩涡区,从而使固相颗粒在补燃室头部的驻留时间得以延长,这对固相颗粒的点火燃烧十分有利,但对提高整个补燃室掺混燃烧效率的作用有限,因此补燃室长度一定的情况下,存在一个最佳的头部距离。     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

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.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

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.     

Open Rule-setting System Applied to Conceptual Design of Engines

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.     

Research on Linux Network Device Driver

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.     

Method for Measuring Velocity of Warhead Fragments Based on Photoelectric Detection

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.     

数码电子雷管中影响点火头性能因素分析

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。     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

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.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

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.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

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.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

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.