Fully C/N‐Polynitro‐Functionalized 2,2′‐Biimidazole Derivatives as Nitrogen‐ and Oxygen‐Rich Energetic Salts

Through the use of a fully C/N‐functionalized imidazole‐based anion, it was possible to prepare nitrogen‐ and oxygen‐rich energetic salts. When N,N‐dinitramino imidazole was paired with nitrogen‐rich bases, versatile ionic derivatives were prepared and fully characterized by IR, and ¹H, and ¹³C NMR spectroscopy and elemental analysis. Both experimental and theoretical evaluations show promising properties for these energetic compounds, such as high density, positive heats of formation, good oxygen balance, and acceptable stabilities. The energetic salts exhibit promising energetic performance comparable to the benchmark explosive RDX (1,3,5‐trinitrotriazacyclohexane).     

A double-front structure of detonation wave as the result of phase transitions

Using thermochemical code calculations, we show that the nanographite–nanodiamond phase transition, which may occur in the detonation products of a number of carbon containing explosives, can affect the detonation properties and can cause a specific detonation regime with some unusual peculiarities. Among them, we first note the failure of the Chapman–Jouguet condition and the presence of the sonic plane, where the Mach number is equal to unity, in a detonation product expansion wave at a lower pressure than that at the Chapman–Jouguet point. The peculiarities of this detonation regime are demonstrated by the example of TNT, HNS, and RDX. The computed detonation velocities are in excellent agreement with experiments over a wide range of initial charge densities for all of the investigated explosives. The results of this work allow one to explain, e.g., contradictory experimental data on the detonation pressure and on the length of the reaction zone for TNT. We believe that some other solid–solid, solid–liquid, and liquid–liquid phase transformations in the detonation products may also cause a detonation regime with the same features as shown here for the nanographite–nanodiamond transition. We suggest a computational study that should facilitate proposing detonation experiments strongly arguing in favor of the model presented. PACS 47.40.-x; 47.40.Rs; 64.70.-p; 64.70.Kb; 05.70.-a; 05.70-.CeThis paper was based on the work that was presented at the 19th International Colloquium on the Dynamics of Explosions and Reactive Systems, Hakone, Japan, July 27–August 1, 2003.     

氢氧混合气体爆轰波的真实化学反应模型数值模拟

采用高精度的ENO格式和基于基元化学反应的真实化学反应模型求解氢氧混合气体一维爆轰波的精细结构。采用直接起爆方法得到稳定传播的爆轰波 ,计算的爆轰波阵面参数和实验相当符合。对爆轰波反应区化学反应的研究表明 ,参与反应的不同组分具有不同类型的变化特征。网格尺寸影响的研究表明 ,计算结果的精度随着网格尺寸的增加而增加 ,并能保持较好的收敛性。移动网格研究结果表明 ,网格运动速度和爆轰速度接近时 ,两者的相互作用对计算结果产生一定影响。     

多循环脉冲爆震发动机流场数值研究

针对二维带有收敛扩张喷管的脉冲爆震发动机模型，采用带基元化学反应的Euler方程组和H2、空气的9组分20基元反应，对发动机在前六个工作循环的流场进行了数值模拟。通过对前几个循环流场进行比较，发现脉冲爆震发动机在第五个循环后流场就基本稳定，单循环得到的流场和多循环稳定后的流场有很大的差别，同时喷管对发动机内流场影响特别大。     

模型复合推进剂燃烧转爆轰研究

本文较详细地研究了模型推进剂(AP/wax,AP/A1/wax,AP/RDX/A1/wax)由燃烧转爆轰(DDT)的过程。分析了装药密度和铝粉含量对装药DDT的影响。结果表明:模型推进剂当其配比接近零氧平衡时较易产生DDT;含与不含铝粉的AP/粘合剂系复合推进剂药柱以及硝胺含量为20％的AP/硝胺炸药/A1粘合剂系复合推进剂药柱都不可能产生DDT。     

Detonability of simple and representative components of pyrolysis products of kerosene: pulsed detonation engine application

The use of liquid fuels such as kerosene is of interest for the Pulse Detonation Engine (PDE). In this context, a representative gaseous mixture of the lighter products resulting from the decomposition of a kerosene of type JP-10 was studied. The detonability limits of simple components (hydrogen, ethylene, propylene) and mixtures of these components were tested in a 50 mm diameter and 2.5 m long detonation tube. This dimension is compatible with the applications of the aircraft industry and more particularly the PDE. The influences of the nitrogen dilution, geometry of the DDT device (Schelkin spiral), ignition energy and initial pressure were investigated. This paper was based on work that was presented at the 19th International Colloquium on the Dynamics of Explosions and Reactive Systems, Hakone, Japan, July 27 - August 1, 2003. Communicated by J.E. Shepherd     

FJZ-1000型超高速转镜分幅相机及其应用

FJZ-1000型超高速转镜分幅相机最高摄影幅频为1107幅/s，画幅总数160幅，尺寸7.5 mm10 mm。光学系统中新加入场镜以使相机的所有画幅均完整成像，使相机摄影频率全面达到标称值的技术指标。配备了新型数字化微机控制台，使相机的操作更加方便，并且实现了两台气动相机的联合拍摄，与脉冲X光机也进行了联动实验。相机达到了设计技术性能指标，实验取得了满意的结果。     

爆轰波拐角传播三维数值模拟

为了研究爆轰波在拐角中的传播特性以及拐角爆轰低压流场现象,用LSDYNA 3D程序对三种常见的拐角装药的爆轰波传播特性进行了数值模拟,清晰显示了爆轰波因拐角处爆轰波传播面积的变化而产生的衰减 增长过程,讨论了侧向三通中爆速的变化情况,并得到了拐角处低压爆轰区的尺寸。     

RESEARCH ON ELECTROMAGNETIC RADIATION DURING THE EXPLOSION PROGRESS OF COMPOSITION B EXPLOSIVES$^{\bf 1)}$

炸药爆炸过程中产生明显的电磁辐射干扰在很多领域引起了重视, 爆炸产生电磁辐射的机理和理论模型都不成熟, 实验仍然是研究这一现象的重要手段. 本文设计了不同质量的B炸药爆炸电磁辐射实验, 测量了爆炸整个过程中不同时刻的电磁辐射信号. 通过小波分析方法对实测信号进行处理, 得到真实信号和信号的时频特点, 小波分析得到真实信号的频谱主要分布在0$\sim$50 kHz. 利用自主开发的EXPLOSION-3D软件对实验工况进行数值模拟, 得到爆炸过程不同时刻流场的特点. 对比实验结果和数值模拟结果得出: 第一个脉冲信号是由B炸药爆轰产生的高温高压等离子体直接产生的电磁脉冲; 第二个脉冲信号是由地面反射的冲击波追上前沿冲击波, 空气冲击波阵面处形成的等离子体产生的电磁脉冲; 第三个脉冲信号是冲击波撞击测量线圈引起的无效信号. 其中, 第一个电磁脉冲幅值与当量的1/3次方基本呈线性关系, 其到达时间对炸药药量不敏感; 第二个电磁脉冲出现的时间与炸药的当量成指数关系, 药量越大, 出现时间越晚. 通过对第二个脉冲信号的分析, 得出了冲击波反射形成电磁脉冲信号时的爆炸波流场特征, 为后续相关理论机理研究提供了验证数据.     

爆轰合成超细金刚石机理探讨

就爆轰合成超细金刚石的机理进行探讨:１．传统的碳相图已不能作为爆轰合成过程的依据；２．由于存在等离子体－晶体的直接相变，整个过程可能有几种相变作用共存；３．爆炸容器中的介质对产物有重要的影响。最后，提出了对整个问题进行研究所应遵循的规律。