低温感发射装药弹道性能的研究

首先分析讨论了低温感发射药燃烧过程 ,并在此基础之上建立了相应的物理模型 ;其次根据密闭爆发器定容燃烧曲线所建立的低温感发射装药燃气生成函数 ,建立了相应的数学模型 ;并据此对低温感发射装药弹道性能进行了模拟计算 ,发现计算结果与火炮实际射击结果基本相符。     

发射过程中某硝胺发射装药的动态挤压破碎情况

利用发射装药动态挤压破碎试验装置对发射过程中低温、常温、高温发射装药的挤压破碎情况进行了模拟动态挤压破碎试验,用发射装药起始动态活度比确定了多种试验条件下破碎发射装药的起始动态活度比,可定量表征发射装药的破碎程度。结果表明,该发射装药在常温、高温下力学性能较好,低温时在相应力学环境下破碎严重。根据试验结果,建立了最大挤压应力与装药破碎程度之间的定量关系。     

DAGR125发射药的燃烧特征

采用密闭爆发器静态试验和30mm高压模拟炮的动态试验,以制式单基药作为对比发射药,研究了DAGR 125发射药的静态燃烧特性及膛内燃烧特征。结果表明,DAGR 125发射药具有低压下起始缓燃的燃烧特性,随压力的升高呈渐增性燃烧特征;在高膛压装药条件下DAGR 125发射药燃烧正常、稳定,膛内p-t曲线光滑,起始负压差小。     

发射装药挤压破碎对燃烧规律的影响

为探索发射装药挤压破碎对燃烧规律的影响,利用发射装药挤压破碎模拟试验装置,对发射药药床进行了系列挤压试验,对不同发射药样品进行了密闭爆发器试验,研究了其挤压破碎发射的密闭爆发器燃烧规律.结果表明,发射药破碎后初始燃烧加强,高压区燃烧减弱.药粒破碎不利于发射装药的发射安全性.     

约束条件对发射装药机械冲击作用下敏感特性的影响

选用制式发射药进行了子弹撞击、破片撞击和空心装药射流撞击试验,研究了钢和可燃药筒的强、弱两种约束条件对发射药在机械冲击作用下敏感特性的影响。结果表明,在子弹撞击和破片撞击的高速机械冲击作用下,约束条件对发射装药的敏感特性响应结果影响明显;强约束条件下发射装药发生燃烧或爆炸响应,弱约束条件下发射装药无响应或发生燃烧响应,在空心装药射流的最强机械冲击作用下,约束条件对发射装药的敏感特性响应结果无明显影响,弱、强约束条件下发射装药的响应结果一致;在发射装药壳体上设计容易泄压的薄弱环节有利于降低发射装药受到意外机械冲击作用时的反应剧烈程度。     

球扁药低温度系数装药研究

设计了一种由松质球扁药和密质球扁药组成的低温度系数装药,其温度系数由混合药中松质药的含量控制。在不同温度下,用密闭爆发试验和30mm火炮试验测定了装药的燃烧性能、膛内压力波和物理稳定性。结果表明,该装药具有较低的温度系数,膛内燃烧稳定,良好的物理稳定性和装药安全性。     

加固参数对加固发射装药燃烧的影响——第一阶段

已广泛开展加固和装药设计参数对高装填密度加固装药燃烧性能影响的研究。本文论及密闭爆发器技术,其目的在于尽可能用定量的方法获得加固装药主要变量对燃烧性能的影响。为了确定粘结剂组成和加固对燃烧性能的影响,用三种形式的IMR4895发射药在密闭爆发器内进行试验:(1)松散,不包复的发射药;(2)松散的,用胶/丙酮或用胶/苯二甲酸二丁酯(DBP)型的粘结剂包复的发射药;(3)用每一种粘结剂成分加固的发射药。本文对三种不同发射药的压力对时间和dp/dt对P/P_(max)曲线进行比较。由此可计算出有效燃速与压力的关系和画出相应的曲线。此外,从实验及结构数据中可算出有效燃烧表面积。也可以计算出三种形式发射药的相对速度(RQ)和相对力(RF)。粘结剂的组成极大地影响加固装药的燃烧性能。本文详细讨论了加固对加固装药燃烧性能的影响,也提出了将来的工作计划。     

加固参数对加固发射装药燃烧的影响——第一阶段

已广泛开展加固和装药设计参数对高装填密度加固装药燃烧性能影响的研究。本文论及密闭爆发器技术,其目的在于尽可能用定量的方法获得加固装药主要变量对燃烧性能的影响。为了确定粘结剂组成和加固对燃烧性能的影响,用三种形式的IMR4895发射药在密闭爆发器内进行试验:(1)松散,不包复的发射药;(2)松散的,用胶/丙酮或用胶/苯二甲酸二丁酯(DBP)型的粘结剂包复的发射药;(3)用每一种粘结剂成分加固的发射药。本文对三种不同发射药的压力对时间和dp/dt对P/P_(max)曲线进行比较。由此可计算出有效燃速与压力的关系和画出相应的曲线。此外,从实验及结构数据中可算出有效燃烧表面积。也可以计算出三种形式发射药的相对速度(RQ)和相对力(RF)。粘结剂的组成极大地影响加固装药的燃烧性能。本文详细讨论了加固对加固装药燃烧性能的影响,也提出了将来的工作计划。     

一种新型发射装药低易损性能的测试研究

为避免弹药在战场上因严酷环境或敌方攻击而产生的燃烧及爆炸事故,对一种新型装药的低易损性能进行了测试研究.根据装药环境的特征评估,通过分析经验数据判断装药可能遭受到的危险源,经危险性评估对试验项目进行剪裁,确定了该装药低易损性能测试项目,并进行了12 m跌落、快速烤燃、子弹撞击和空心装药射流试验.结果表明,该新型装药可初步满足低易损性弹药的性能评定要求.     

炸药装药工艺对发射安全性的影响

利用大落锤撞击模拟加载装置，对铸装和压装两种装药条件下的B炸药进行了模拟火炮膛内发射主要加载应力试验，结果表明，在装药其它条件相同的情况下，压装药相对钝感，其发射安全性略优于铸装药。     

低温烧成纯铝酸钙水泥的机理研究

在常压条件下水热合成水化铝酸钙，然后经过低温烧成制备了纯铝酸钙水泥。通过力学性能的测试，并采用XRD，DTA等分析方法，探讨了低温烧成纯铝酸钙水泥的机理。研究结果表明：采用水热合成处理方法制备纯铝酸钙水泥，烧成温度低（1250℃，制得熟料活性好，强度高，是替代传统烧结法制备纯铝酸钙水泥的新方法。     

水热合成-低温煅烧活化低钙铝酸盐水泥的研究

采用Al2 O3和CaO为原料 ,在实验室常压下水热合成水化铝酸钙 ,然后低温煅烧制备活化低钙铝酸钙水泥。结果表明 :可制备以CA2 为主的低钙铝酸盐水泥 ,降低熟料烧成温度 ,产品较传统烧结法产品活性高、强度高     

高能硝胺发射药在高膛压火炮上的使用安全性

采用30mm高压模拟炮试验研究手段和与单基药相对比的方法,对RGD7发射药在高膛压下的膛内压力波特征、内弹道适应性及其低温动态燃烧活性进行了研究与分析。结果表明,RGD7发射药低压下缓燃的燃烧特性有利于改善其在火炮膛内的受力环境,并表现出较好的内弹道适应性,具有良好的使用安全性,但其低温动态燃烧活性偏大,应用中需要加强控制,并进一步改善其低温力学性能。     

RDX-CMDB推进剂燃速温度敏感系数的实验研究

为了揭示RDX-CMDB推进剂中各常见组分对其燃速温度敏感系数的影响规律,制备了一系列含RDX、铝粉及燃烧催化剂的CMDB推进剂样品。采用氮气靶线法测得其在2~14MPa下的燃速温度敏感系数(σp)。讨论了RDX含量、铝粉、燃烧催化剂对RDX-CMDB推进剂燃速温度敏感系数的影响。结果表明,提高工作压强、增加RDX含量、添加燃烧催化剂均有助于降低RDX-CMDB推进剂在一定初始条件下的燃速温度敏感系数。配方中引入铝粉后可降低中低压下RDX-CMDB推进剂的燃速温度敏感系数,且燃速温度敏感系数几乎不随压强变化而变化。选用含邻苯二甲酸铅和没食子酸铋锆作燃烧催化剂,均可在2~10MPa下降低RDX-CMDB推进剂的燃速压强指数,同时降低燃速温度敏感系数。     

亚大气压下AP/HTPB微尺度稳态燃烧的数值模拟

为研究亚大气压下高氯酸铵/端羟基聚丁二烯(AP/HTPB)的燃烧特性,采用三步反应动力学机理,建立二维三明治模型,耦合气固两相;对20~80kPa下AP/HTPB的微尺度燃烧进行模拟,并与高压下(4MPa)AP/HTPB燃烧特性差异进行对比。结果表明,亚大气压下BDP模型中第一步反应靠近燃面,放热量较大,在AP/HTPB推进剂燃烧过程中占主导地位;燃烧环境压强不同,导致火焰的特性不同,亚大气压下火焰中扩散与混合过程共存,高压下为扩散火焰;相比于高压,亚大气压火焰离燃面远,面积大;由于高低压下放热区域及放热率差异导致气固相温度分布不同,从而影响燃面形状,亚大气压下AP与HTPB交界处相对于整个燃面突出,而高压下交界处相对于整个燃面凹陷。     

Burning Characteristics of Microcellular Combustible Ordnance Materials

A microcellular combustible ordnance material composed of 70 % RDX (cyclotrimethylene trinitramine) and 30 % PMMA (poly methyl methacrylate) was fabricated using the solvent method and foamed by supercritical CO₂ as foaming agent. This material has a number of advantages and many find potential application in weaponry. In this paper, vented bomb tests were conducted on the porous materials to gain a qualitative understanding of how the material is burning in a gun environment. The extinguish process showed that the microcellular combustible material followed the in‐depth combustion mode, i.e. the combustion products infiltrated through inner pores as well as ignited the inner pore surface. With increasing burning degree, the depth and perforation size of infiltration zone increased. Closed bomb tests were also conducted to investigate the influences of test conditions on the burning behaviors. The results showed that when the ignition pressure was increased from 10.98 MPa to 15.0 MPa, the burning time was shortened, but the mass burning rate and vivacity did not change obviously. Mass burn rates at different loading densities indicated that while the pressure in closed vessel is high enough (p≥40 MPa), hot combustion gases were driven into the inner pores and convectively ignited the inner pores. The closed bomb results conducted at high and low temperature showed no abnormal burning behavior at low and high temperature can be observed.     

Experimental study of the burning behavior of n‐heptane pool fires at high altitude

The same configured calorimeters were built in Hefei (99.8 kPa) and Lhasa (66.5 kPa), respectively. Four sizes of round pans with diameters of 10, 15, 20, and 25 cm were adopted to study the effect of high altitude on the burning behavior of liquid pool fires. Analysis on the burning rate obtained in this study and in the literature at different altitudes indicates that pressure fire modeling performs better than radiation fire modeling in correlating the burning intensity (burning rate per unit area) with pressure and pool diameter for cases under low ambient pressure. The study also shows that heat release rate and combustion efficiency decrease at higher altitude. For medium pool fires, the burning intensity and heat release rate are proportional to D^5/2, thus the combustion efficiency being independent on pool sizes but decreases at higher altitude by a factor approximate to the pressure ratio. Copyright © 2014 John Wiley & Sons, Ltd.     

Decomposition and Ignition of the High‐Nitrogen Compound Triaminoguanidinium Azotetrazolate (TAGzT)

The high‐nitrogen compound triaminoguanidinium azotetrazolate (TAGzT) belongs to a class of C, H and N compounds that are free of both oxygen and metal, but retain energetic material properties as a result of their high heat of formation. Its decomposition thus lacks secondary oxidation reactions of carbon and hydrogen. The fact that TAGzT is over 80% nitrogen makes it potentially useful as a gas generant and energetic material with a low flame temperature to increase the impulse in gun or rocket propellants. The burning rate, laser ignition and flash pyrolysis (T‐jump/FTIR spectroscopy) characteristics were determined. It was found that TAGzT exhibits one of the fastest low‐pressure burning rates yet measured for an organic compound. Both the decomposition and ignition behavior of TAGzT are dominated by condensed phase reactions. T‐Jump/FTIR spectroscopy indicates that condensed phase reactions release about 65% of the energy, which helps to explain the high burning rate at low pressure.     

甲烷/乙烷/空气预混火焰层流燃烧速度与火焰稳定性的数值研究(英文)

A numerical study on premixed methane/ethylene/air flames with various ethylene fractions and equivalence ratios was conducted at room temperature and atmospheric pressure. The effects of ethylene addition on laminar burning velocity, flame structure and flame stability under the condition of lean burning were investigated. The results show that the laminar burning velocity increases with ethylene fraction, especially at a large equivalence ratio. More ethylene addition gives rise to higher concentrations of H, O and OH radicals in the flame, which significantly promotes chemical reactions, and a linear correlation exists between the laminar burning velocity and the maximum H + OH concentration in the reaction zone. With the increase of ethylene fraction, the adiabatic flame temperature is raised, while the inner layer temperature becomes lower, contributing to the enhancement of combustion. Markstein length and Markstein number, representative of the flame stability, increase as more ethylene is added, indicating the tendency of flame stability to improve with ethylene addition.     

Burning Behaviour of ADN Formulations

The application of ADN for an effective oxidizer of propellants and explosives requires a detailed knowledge of the burning behaviour. The physical and chemical mechanisms of the combustion depend on pressure. Especially profiles of temperature and species in the flame are important to design propellant formulation of high performance and low signature of the rocket plume. In the presented study, pure ADN and ADN/paraffin mixtures were investigated as strands in an optical bomb at pressures of 0.5 MPa to 10 MPa. The application of non-intrusive combustion diagnostics for the investigation of fast burning energetic materials allowed the measurement of burning rates and profiles of temperature and gas components at various distances above the burning propellant surface. The burning rate was determined by using a video system and a special frame analysis. The acquisition and analysis of emission spectra in the UV/VIS allowed the investigation of rotational temperatures, the determination of particle temperatures and the identification of transient flame radicals. The vibrational temperatures of final combustion products resulted from band spectra emitted in the near and mid infrared spectral range. Burning rates of 5 mm/s to 70 mm/s were recorded showing a mesa/plateau-effect in the pressure range of 4 MPa to 7 MPa. The UV/VIS spectra indicated an emission from OH, NH and CN radicals. The strong emission of OH bands of the ADN/paraffin mixture allowed the investigation of rotational temperatures with a mean value of 2700 K which is closely below the adiabatic flame temperature of 2950 K. Additionally, one-dimensional intensity profiles of the flame radicals were measured. As combustion end products H₂O, CO, CO₂ and NO were found. NO could only be detected at a distance up to 2 mm above the propellant surface. The measured CO/CO₂ fraction was higher as 10/1. Water could only be detected far above the propellant surface.