梯恩梯/萘共晶初始热分解的反应分子动力学模拟

ReaxFF反应力场在冲击起爆、爆轰等问题中的应用多围绕常规含能材料。利用增加了长程修正项E_lg的ReaxFF/lg反应力场对梯恩梯/萘（TNT/C₁₀H₈）共晶初始高温热分解进行模拟,并通过TNT单晶比较了C₁₀H₈对共晶整体反应特征的影响,利用指数函数及反应速率方程拟合得到共晶初级吸热反应和次级放热反应的活化能分别为35.7 kcal/mol和56.1 kcal/mol. 初级吸热反应的活化能与TNT单晶基本相同,而次级放热反应的活化能则远远高于TNT单晶,并且同温度条件下共晶次级反应放热量小于TNT单晶。拟合得到的反应物的衰减速率表明,C₁₀H₈的加入将抑制共晶内TNT的分解。产物识别分析显示初始产物为NO₂、NO和HONO,并且通过NO₂和TNT_—NO2,NO和TNT_—NO,HONO和TNT_—HONO分布数量的比较论证了固相共晶和TNT单晶的初始反应路径为双分子反应机制。共晶热分解最终主要产物为N₂,H₂O,CO₂和CO. 并且由于共晶内C₁₀H₈分子C—C键断裂所需的能量高于C—H键断裂所需的能量,C₁₀H₈分子的初始热分解路径为C—H键断裂,并且形成的H原子将促进共晶内H₂O的产率高于TNT单晶内H₂O的产率。     

舱室密闭空间中爆炸载荷后燃烧效应数值计算研究

为准确分析梯恩梯炸药在密闭空间中的爆炸载荷,在统一设施标准模型和基于能量守恒的简化计算公式基础上,提出了一种计算爆炸产物后燃烧能量的方法。该方法应用到基于有限元分析软件ANSYS/AUTODYN平台的数值模拟中,实现负氧平衡炸药在密闭空间中爆炸过程的数值仿真计算。计算结果与试验测试结果表明：梯恩梯炸药在密闭空间中发生爆炸时,其爆轰产物的后燃烧效应不可忽视;不考虑爆炸产物的后燃烧效应,数值计算得到的准静态压力较试验值低55%以上,50 ms内冲量较试验值低49%以上;将爆轰产物的后燃烧能量计入后,爆炸压力及冲量时程的计算值与试验值吻合较好,为结构受爆炸载荷响应分析提供了准确的输入载荷。     

十二氢十二硼酸双四乙基铵对铝粉燃烧反应机理的影响

为了探究固体硼氢燃料对铝粉燃烧反应机理的影响,采用同步热分析?红外质谱联用技术及热裂解原位池?傅里叶变换红外光谱联用技术,对十二氢十二硼酸双四乙基铵(BHN?12)的热分解反应机理及反应动力学进行研究.在此基础上,结合数值模拟建立BHN?12在爆炸流场中对铝粉燃烧反应影响的模型,探究硼氢燃料在流场中的反应时间、分散特性以及对铝粉的助燃效应.结果表明,BHN?12热分解开始温度约314℃,结束温度约360℃.分解过程中出现三个放热峰和两个吸热峰,总质量损失范围为32.3％～33.9％.分解过程遵从幂级数法则(Mampel power),动力学机理函数为G(α)=α1/2.分解后的气体产物主要为H2、C2H4、C2H6和NH3,固体产物为非晶态的C和B单质.采用组分运输模型可较好地模拟Al/BHN?12体系的后燃烧反应过程,在该过程中,Al燃料的分散速度比BHN?12粒子的分散速度慢,20 ms时,Al燃料的分散半径约2.5 m,BHN?12的分散半径约3 m.在反应初期2 ms时,无分解气体产物出现;大约4 ms时,开始出现气体产物,反应火球中部的温度约为1800℃,BHN?12可提升体系的后燃反应温度约300℃.     

单质炸药在等离子体作用下的起爆响应

为了得到单质炸药在等离子体作用下的起爆响应规律,以镍-铬(Ni-Cr)丝和钨丝电爆炸作为等离子体产生源,进行了单质炸药的等离子体起爆实验,采用示波器测定等离子体的电压和电流,以见证板判定炸药是否爆轰。结果表明,Ni-Cr丝等离子体对奥克托今(HMX)的起爆能力强于钨丝等离子体。选用粒度21μm和140μm,装药密度相差10%的HMX起爆,粒度较小和装药密度较小时,HMX的等离子体起爆响应更剧烈。单质炸药奥克托今(HMX),2,6-二氨基-3,5-二硝基吡嗪-1-氧化物(LLM-105),1,1-二氨基-2,2-二硝基乙烯(FOX-7),N-脒基脲二硝酰胺盐(FOX-12),三氨基三硝基苯(TATB)可被等离子体起爆。2,4-二硝基苯甲醚(DNAN)由电爆炸产生的热作用引燃。炸药的Ni-Cr丝等离子体感度顺序为:HMXLLM-105≈FOX-7FOX-12TATB。推断等离子体起爆炸药的机理为混合起爆。提出了基于等离子体的颗粒燃烧模型。     

Mg(BH4)2对典型硝胺炸药热分解性能的影响

为探索硼氢化镁(Mg(BH₄)₂)对硝胺炸药热稳定性的影响,采用差示扫描量热法(DSC)研究了Mg(BH₄)₂/黑索今(RDX)、Mg(BH₄)₂/奥克托金(HMX)和Mg(BH₄)₂/六硝基六氮杂异伍兹烷(CL-20)3种混合物的热分解性能,并采用同步热分析-红外连用技术(TG-FTIR)分析了3种混合物的热分解气相产物。结果表明：Mg(BH₄)₂对3种硝铵炸药的热分解和表观活化能产生了不同的影响,使RDX和CL-20分解放热量分别增加了14.7%和32.1%,HMX的分解放热量减少了45.8%;RDX的表观活化能降低了15.8 kJ·mol^-1,HMX和CL-20的表观活化能分别提高了19.7 kJ·mol^-1和11.5 kJ·mol^-1。Mg(BH₄)₂没...     

含微/纳米铝粉燃料空气炸药爆炸特性

利用20 L爆炸装置开展了含微/纳米铝粉燃料空气炸药爆炸特性研究.试验结果表明:微米铝粉中加入5％和10％纳米铝粉后,混合铝粉爆炸压力峰值增幅分别为24.4％和58.5％,最大压力上升速率增幅达到80.6％和103.4％,纳米铝粉含量大于10％对于爆炸效应增加没有明显作用;固液比为30/70的燃料空气炸药,点火能从11.83 J增加到28 J,其爆炸压力从0.28 MPa增大到0.52 MPa,爆炸温度从834℃增大到1118℃,表明增大点火能可以提高燃料空气炸药爆炸参数;提高微/纳米铝粉含量,能够有效提高固液型燃料空气炸药爆炸压力和爆炸温度.     

高活性AlMg/KMnO4铝热剂的性能研究

采用机械球磨法制备了不同比例的AlMg 合金,采用超声分散法制备了AlMg/ KMnO₄ 铝热剂,该种铝热剂有希望成为一种有潜力应用于反应材料和火炸药领域的含能材料。通过DSC、点火温度和燃烧产物分析,对AlMg/ KMnO₄ 进行了表征分析。结果表明:随着镁含量的增加,AlMg/KMnO₄点火温度明显降低,从723 K 降低至493 K,反应活性得到大幅提高;在AlMg/ KMnO₄ 铝热剂的燃烧产物中出现了Al₂O₃、MgO 以及Mn 单质,可知Mn 单质是AlMg/ KMnO₄ 发生的铝热反应生成的;综合DSC 曲线还可以进一步得出与AlMg 合金发生反应的是KMnO₄ 的分解产物而不是KMnO₄.     

HMX基含硼铝炸药的释能特性和作功能力

如何有效地运用活性金属来提高炸药的爆炸威力和作功能力是设计金属化炸药的关键问题.为探索B/Al复合粉在增爆炸药和温压炸药中的应用,设计并制备了3种HMX基含硼铝炸药.对Φ100 mm×105 mm样品,用空中爆炸试验和水下爆炸试验研究其能量释放特性;用Φ50 mm圆筒试验评价其作功能力,讨论了微米金属粉含量对含硼铝炸药的释能过程和作功能力的影响.结果表明,空爆和水下爆炸中,在HMX的爆轰作用下,铝粉燃烧能够促进硼粉的后燃效应,释放出大量的燃烧热,形成高温高压的膨胀产物,增加空中爆炸火球的持续时间和水下爆炸的总能量.圆筒试验中,在爆轰产物驱动铜管膨胀破裂之前,没有足够的氧和硼反应,未能体现含硼铝炸药中B的燃烧能量优势.当铜管壁膨胀破裂后,空气中的氧可进一步与B/Al复合粉反应释放大量的燃烧热,增强后效作功能力.     

负压条件下柱形爆炸罐内爆炸波传播规律

为分析负压条件下柱形爆炸罐内爆炸波的传播特性,自行设计尺寸为320 mm× 430 mm的 可调真空度柱形爆炸罐,开展不同真空度条件下的内爆实验。通过内爆实验研究,获得了不同真空度下爆炸波的传播速度u、超压Δp、比冲量i、相对压力因子α和相对比冲量因子γ等爆炸波参数。结果表明：罐体内真空度的改变对爆炸波传播状态产生了显著影响,罐体内初始压力降低时,爆炸波超压和比冲量均有不同程度的衰减;当罐体内初始压力由常压降低至0.1 atm时,第1个爆炸波超压Δp₁的相对压力因子α_1max为2.41,第2个爆炸波超压Δp₂的相对压力因子α_2max为 1.64;第1个爆炸波比冲量i₁的相对比冲量因子γ_1max为6.97,第2个爆炸波比冲量i₂的相对比冲量因子γ_2max为3.14;α和γ分别反映了爆炸波超压和比冲量的衰减程度,α和γ的值越大表明爆炸波超压和比冲量衰减得越快;爆炸波的传播速度会随着初始环境压力的改变而发生变化,初始环境压力越低,爆炸波的传播速度越快。     

含硼储氢合金(Mg(BH_x)_y)对硝酸酯炸药能量的影响

为提高硝酸酯炸药的爆炸能量,将含硼储氢合金(Mg(BH_x)_y)添加到硝酸酯炸药中,用水下爆炸试验和空中爆炸试验研究了含Mg(BH_x)_y的硝酸酯炸药的能量和后燃效应。结果表明,Mg(BH_x)_y能显著提高硝酸酯炸药的能量。空中爆炸试验中,Mg(BH_x)_y发生分解,分解产物参与爆轰反应。水下爆炸试验中,添加Mg(BH_x)_y后硝酸酯炸药的爆炸能量提高17.56%,且含Mg(BH_x)_y硝酸酯炸药具有明显的后燃效应。     

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.     

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.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.     

A Study on the Estimation of Aeroheating upon the Warhead Nose at Supersonic Speed

An expression for estimating the aeroheating on a warhead nose at different supersonic speeds is proposed by incorporating CFD （computational fluid dynamics） and the least-square method. Compared with the traditional estimation formula, the expression is more accurate, convenient and can be used in the optimized design of warheads. The error from the result obtained in the test of a ball cartridge flight is less than 3 %. It satisfies the engineering requirements.     

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.