镁铝富燃料推进剂热值的均匀性和稳定性及不确定度分析

以成熟的镁铝富燃料推进剂配方为基础,通过改进推进剂的制备工艺制备了含镁铝富燃料推进剂.采用恒温式氧弹热量计测试了系统取样的含镁铝富燃料推进剂的热值;用方差和T检验法研究了镁铝富燃料推进剂热值的均匀性和稳定性,并对有关测试不确定度进行了分析.结果表明,含镁铝富燃料推进剂热值具有较好的均匀性和稳定性,扩展不确定度小于3.0(k＝2).     

提高碳氢富燃料推进剂燃速压强指数研究

研究了碳氢富燃料固体推进剂中固体组分的种类、含量、规格,燃速催化剂的种类、含量等因素对配方燃速压强指数(简称压强指数)的影响。结果表明,碳氢富燃料推进剂的压强指数随氧化剂含量的适度降低和固体碳氢燃料TQ粒度的减小而升高,当w(N9)为3%时,压强指数达到最高,以Mg作金属燃烧剂和以EM作燃烧催化剂的配方有较高的压强指数。通过优化上述因素,推进剂的压强指数达到了0.62~0.66。     

铝基合金燃料在HTPB推进剂中的应用

通过改变铝基合金燃料类型制备低铝含量推进剂,在此基础上进行铝基合金的粒度、形貌和推进剂的爆热、燃速测试,研究了不同铝基合金燃料对端羟基聚丁二烯(HTPB)推进剂工艺性能、燃烧性能及安全性能的影响。推进剂组分相同时,黏度数据表明,铝基合金的不规则形貌是引起推进剂工艺恶化的主要因素,粒度差异会使工艺性能有所不同;燃烧性能测试和爆热测试结果表明,添加铝基合金AN(铝-镍合金燃料)和AT(铝-钛合金燃料)后,与含球形铝粉推进剂相比,推进剂密度增加,燃速压强指数降低,爆热水平相当,燃烧性能得到了改善;添加铝基合金燃料后造成推进剂的摩擦感度上升。     

含硼富燃料推进剂的技术现状与发展趋势

综述了国内外在硼粒子的点火、燃烧性能,硼粉的包覆、团聚造粒技术,硼粉处理对配方性能的影响,含硼富燃料推进剂配方及性能测试表征手段等方面的研究进展。总结了国内外含硼富燃料推进剂工程化应用的现状和存在的差距。     

铝/冰固体推进剂的改良

针对如何提高铝/冰固体推进剂的综合性能,从氧化剂和燃料两方面进行了概述,指出引入H_2O_2和AlH_3均可提高推进剂的比冲,还可调节其燃烧性能;并对铝/冰固体推进剂的发展方向进行了展望。     

团聚硼对富燃料推进剂燃速的影响

通过调节黏合剂种类和团聚工艺,采用于法硼团聚工艺制取球形度良好、粒径为0．105～0．19mm的团聚硼粒子,并制得硼质量分数32％、热值约32MJ／kg、工艺性能良好的含硼富燃料推进剂;采用靶线法测试含硼富燃推进剂的燃速及压强指数,并测试不同AP粒度级配、镁铝合金粒径以及团聚硼粒径对富燃推进剂燃速的影响。结果表明,减小AP粒度及团聚硼粒径、增加超细AP含量和固体组分含量,可大大改善含硼富燃推进剂的燃烧性能。而镁铝合金粒径对推进剂的燃烧性能基本没有影响。     

铝基合金燃料的研究及其在固体推进剂中的应用进展

为了阐明元素组成和相组成与铝基合金燃料本征特性的关系，分别总结了低沸点金属、低熔点金属和高熔点金属作为合金元素时对理化特征和燃烧特性的影响规律，分析了不同铝基合金燃料点火和燃烧机制的差异。铝基合金燃料在燃烧过程中，存在Al-M_LB的微爆、Al-M_LM中的合金化放热/氧化通道、Al-M_HM中的亚稳相放热等多种燃烧效率提升的机制。从能量提升和燃速调控两方面归纳了铝基合金燃料在固体推进剂中的应用研究概况，指出铝基合金燃料通过理论比冲提升、燃烧效率提升、二相流损失降低和密度提升等途径提高了推进剂的能量性能；铝基合金燃料对推进剂燃速的影响是配方各组分相互作用的结果，调控效果随着配方中的氧化剂、黏合剂成分而发生改变。掌握铝基合金燃料“制备工艺-结构-性能”的关系、解决安全性和长期储存活性降低问题和完善燃速调节机制及燃烧反应释能机理，是铝基合金燃料的设计、应用和性能调控的关键。附参考文献75篇。     

含呋咱衍生物富燃料推进剂的能量性能

采用最小自由能法,研究了含呋咱衍生物的Al/Mg/HTPB/AP富燃料推进剂的能量性能,结果表明,随着呋咱衍生物含量的增加,富燃料推进剂比冲明显增加,其中含质量分数为25%的DAAzF(4,4'-二氨基-3,3'-偶氮呋咱)的富燃料推进剂比冲可达7 522.9 N·s·kg-1,比相同质量含量下含CL-20富燃料推进剂比冲高260N·s·kg-1.含呋咱衍生物富燃料推进剂气相平均相对分子质量((-M)g)约为29,补燃室火焰温度(Tc)约为2 200K,且二者随着呋咱衍生物含量增加而略有增加.     

含硼温压型燃料的爆炸性能

研究了超细硼粒子在温压型燃料爆炸中的能量效率，通过理论计算、实验室测试和外场实验比较了硼、镁、铝等添加剂在温压燃料中的性能。结果表明，虽然含硼燃料的能量明显高于含镁、铝燃料，但其点火和燃烧条件较为苛刻。爆炸试验时，在相同爆心距处，含硼温压燃料试样的爆炸冲击波压力与含镁、铝温压燃料试样相比没有明显优势。含硼燃料试样的爆炸火球温度较高、高温维持时间更长。为了提高燃料中硼粉的能量效率，需要提供初始高温环境和适当的氧浓度，改善硼粒子的燃烧性能。     

合金燃料在固体推进剂中的应用

介绍了合金燃料的特点及其制备方法,并对合金燃料在固体推进剂中的应用研究情况进行了综述.认为合金燃料具有点火性能好、点火温度及熔点可调、燃烧效率高等优点,而且对推进剂的燃烧性能有重要影响.其中贮氢合金燃料有较高的生成焓,与推进剂组分有良好的相容性,在高能推进剂中有良好的应用前景.     

An experimental study on the hypergolic ignition of hydrogen peroxide and ethanolamine

This paper presents the hypergolic ignition test results of a potential environmentally friendly liquid propellant consisting of hydrogen peroxide oxidizer (with a concentration of 85%) and ethanolamine fuel for use in rocket engines. Open cup drop tests were conducted to study the effect of amount of metal salt catalyst in fuel and the initial temperatures of fuel and oxidizer on the ignition delay time. To test the hypergolic ignition of bipropellant formulation in a real rocket engine environment, a pressure-fed liquid propellant rocket engine (LPRE) was designed and developed. During the tests it was found that the amount of catalyst and the initial temperature of the fuel had a significant effect on the ignition delay of hypergolic bipropellant. However, the oxidizer temperature seemed to have almost no affect on the ignition delay. There was also significant difference between the ignition delay times from open cup tests and those from rocket engine static firings.     

Hypergolic Studies of Ethanol Based Gelled Bi‐Propellant System for Propulsion Application

The experiments conducted in this study examined the hypergolicity and ignition delay of the formulated ethanol gelled fuel and hydrogen peroxide oxidizer bipropellant system. The hypergolicity and ignition delay data for bipropellant system are very important for propulsion applications. It was observed that the ethanol based gelled fuel systems were hypergolic with hydrogen peroxide (90% pure) in a presence of a suitable catalyst. The observed ignition delay was within the range of 10∼50 ms, which was comparable with the existing liquid hypergolic bipropellant systems. Temperature profile also indicated that the hypergolic system attained a very high temperature profile range of 1000 °C to 1400 °C for a very small weight percent of fuel. Experiments conducted with two separate volumes of oxidizer, 14 μl and 50 μl. In both cases the propellant system was fuel rich. It was also observed that the formation of cage in the gel network, which could encapsulate the higher temperature gases and flame in a network, might be a plausible reason for recorded higher ignition delay.     

Ignition and Combustion of Condensed Systems with Energy Fillers

This paper describes the results of an experimental study of ignition and combustion of condensed systems, containing energy fillers, i.e., powders of aluminum, boron, aluminum borides, and titanium. Compositions on a hydrocarbon or active fuel binder with a combined oxidizer (ammonium perchlorate and/or ammonium nitrate) are considered. Thermodynamic estimates for the ballistic characteristics of the compositions under study are given. It is shown that a unit pulse increases by 3.5% with the replacement of aluminum by boron in the compositions considered. It is experimentally determined that the time delay of ignition of boron-containing compositions decreases in conductive and radiant heat transfer and that the stationary burning rate of boron and aluminum boride containing compositions increases. The efficiency of the impact of energy fillers on the characteristics of condensed systems as a function of the composition of a combined oxidizer is determined.     

Experimental Investigation on Laser Ignition and Combustion Characteristics of NEPE Propellant

The ignition and combustion property of solid propellant is the main content in internal ballistic research, which has a great significance for propulsion application and combustion mechanism. In this study, the detailed gas‐phase reaction mechanism of Nitrate Ester Plasticized Polyether Propellant (NEPE) was developed. It is helpful to understand the intricate processes of solid‐propellant combustion. The factors which may have influences on ignition delay time and temperature distribution of propellant surface was analyzed by laser ignition experiment. Using high‐speed camera and an infrared thermometer, the ignition and combustion process and the surface temperature distribution of NEPE propellant under laser irradiation were measured. Laser heat flux, ambient pressure and initial temperature of NEPE propellant have an influence on the ignition delay time and the surface temperature. Results show that the ignition delay time decreases with the increase of laser heat flux, ambient pressure and initial temperature of NEPE propellant. At the same time, with the increase of laser heat flux, the influences of ambient pressure and initial temperature on the ignition delay time decrease. Besides, laser irradiation, ambient pressure and initial temperature have significant influences on the surface temperature distribution of the propellant.     

Laser Ignition of Various Pyrotechnic Mixtures – an Experimental Study

Ignition of several pyrotechnic mixtures by diode‐laser was studied experimentally using a novel combustion chamber. The ignition delay times dependence on laser intensity could be fit by the expression t_ign=aI⁻ⁿ for all compositions, with I being the laser intensity at target and n=1.4–2.1. This is roughly in accordance with thermal ignition theories assuming a semi‐inert solid. Differences in ignition delay times did not depend on fuel alone or oxidizer alone. The temperature of oxidizer decomposition does not correlate with ignition delay time. Furthermore, the steady state combustion temperature, deduced from emission spectra of the composition products are not correlated with ignition delay time. It is proposed that chemical reactions, taking place in the gas‐phase or in the solid‐phase, play a significant role, but are not solely responsible for ignition delay time. The seemingly uncorrelated ignition delay results between pyrotechnics containing either the same fuel or oxidizer hamper the construction of a “unified theory” for laser ignition of pyrotechnic mixtures.     

带延迟点火部件的发射药点火性能试验研究

为了更好地研究发射药的点火性能,在基于密闭爆发器原理的点火性能测试装置基础上增加了一个延迟点火部件,构建了一个新型点火性能模拟试验装置,根据该装置建立了简单的火药分层点火过程模型,模拟并对比了高能太根-18/1、双芳-3-18/1及NR11-18/1三种发射药的点火性能。结果表明,NR11-18/1发射药较易点火,双芳-3-18/1发射药最难点火,点火时间分别为19和45ms。增加延迟点火部件后,可将点火药的燃烧和发射药的燃烧阶段有效区分,不仅有利于对比点火性能差异较小的发射药之间的区别,还有助于分析发射药低压段的燃烧速度。随着延迟点火部件长度的增加,点火时间也增长。     

Effect of ignition temperature and fuel amount on photocatalytic activity of solution combustion synthesized ZnO

Nanocrystalline zinc oxide (ZnO) photocatalyst has been synthesized by a simple solution combustion method using zinc nitrate as the oxidizer and urea as the fuel. Effect of fuel to oxidizer ratio and ignition temperature on the mechanism of combustion synthesis, crystallinity, morphology, surface area, and optical properties were investigated by thermal analysis, X-ray diffraction (XRD), Scanning electron microscopy (SEM), Diffuse reflectance UV–Visible spectra and Photoluminescence analyses. Photocatalytic activity of the synthesized materials was evaluated by degrading an azo dye at ambient temperature and solution pH. The prepared photocatalysts at the fuel-rich condition possess small crystallite size and more surface area; consequently, a higher photocatalytic dye degradation capability.The powder samples synthesized at the fuel-oxidant ratio of 1.8 and the ignition temperature at 400 °C have shown the maximum percentage (99%) of dye degradation in 180 min. The pseudo-first order photocatalytic dye degradation rate constant of a catalyst sample synthesized at the fuel-oxidant ratio of 1.8 was 0.0253 min⁻¹and it is 3.14 and 2.88 times higher than that of samples synthesized at fuel-oxidant ratios of 0.6 and 1.The outcomes of the present article help to design more pronounced experiments for the synthesis of photocatalysts by varying ignition temperatures and fuel amounts.     

国外低特征信号富燃料推进剂的研究进展

综述了国外低特征信号富燃料推进剂的研究进展,归纳了研究低特征信号富燃料推进剂的技术途径。认为碳氢富燃料推进剂具有低特征信号的特点,是研究低特征信号富燃料推进剂的基础,采用非金属燃料是降低推进剂一次烟烟雾特征信号的有效途径,通过添加剂消除HCl是降二次烟的有效手段。对我国低特征信号富燃料推进剂的发展提出了几点建议。     

含团聚硼富燃料推进剂的能量特性及燃烧性能

用最小自由能计算程序计算了含硼富燃料推进剂的能量性能,探讨了不同压力时硼粉的质量分数对富燃料推进剂能量性能的影响,采用靶线法和化学滴定法研究了富燃料推进剂的燃烧特性和燃烧残渣中硼粉的燃烧效率。结果表明,随着硼粉含量的增加,推进剂的能量增大;大粒径的团聚硼对富燃料推进剂的燃速和压强指数影响较大,随着团聚硼含量的增加,推进剂的燃速提高;含硼富燃料推进剂中的硼粉燃烧后单质硼和硼化物的摩尔比发生了明显的变化,无定形硼粉经团聚后燃烧效率明显提高。