变燃速发射药内弹道参数的预估

运用内弹道势平衡理论将待测药和基准药的密闭爆发器实验数据及基准药的内弹道参数相联系,得到待测药与基准药最大膛压与炮口初速的关系式。以双基类XSX-1型和单基类XNX-1型变燃速发射药为基准药,以其在某火炮的内弹道参数为标准,分别对双基和单基变燃速发射药的炮口初速和最大膛压进行预估。结果表明,运用势平衡理论对变燃速发射药最大膛压和炮口初速进行预估是可行的,其结果具有准确性;预估结果能够体现药型尺寸与配方对变燃速发射药内弹道参数的影响。     

球形变燃速发射药的燃气生成规律

通过建立该类药型气体生成猛度与已燃发射药质量分数的理论表达式,对影响球形变燃速发射药的燃气生成规律进行理论分析。在服从几何燃烧定律的条件下,以球形变燃速发射药的初始药形尺寸以及内外层燃速比k、密度比y为基本变量,推导出球形变燃速发射药的表达式。在取值相同的情况下,根据药型和形状函数分别进行了计算和分析,得到了球形变燃速发射药的计算曲线。计算结果表明:适当调节发射药的初始药形尺寸及内外层药的燃速比k、密度比y的值时,可控制球形变燃速发射药的能量释放规律。当内外层燃烧比增加3倍时,气体生成猛度最大值增加约为2.2倍。     

变燃速发射药线膨胀系数关系的实验研究

为了解双层变燃速发射药的热膨胀性能规律,采用膨胀系数测定仪测定了一种类双基型中心开孔双层变燃速发射药的线膨胀系数,结果表明,外层药的线膨胀系数大于内层药的线膨胀系数.推导了变燃速药型的轴向线膨胀系数与内、外层药的线膨胀系数以及几何尺寸之间的理论关系式,并计算了变燃速发射药的线膨胀系数,与实测值的相对误差小于10%.     

双基发射药的超声挤压

为了测量超声活化对N5和XM—33无溶剂双基火箭发射药挤压速率的效应,已经在一个2时(5厘米)实验挤压机上进行了挤压研究,结果发现,应用的超声功率达到180声瓦就可将N5发射药的挤压速率提高到15％～360％,将XM-33发射药的挤压速率提高到110％～315％,就每种发射药而言,单位压力下的挤压速率随超声功率的增加而增加,用半活性N4发射药进行的安全试验说明,超声功率的应用不会引起发射药的过热,即使在极端条件下也是不会的,已经用实验挤压过程中获得的数据充实了在15时(38厘米)产品挤压机上挤压MK43 2.75时火箭发射药粒的标准超声活化系统的设计。     

粒状发射药接触角测定条件的优化

为获得较为准确的粒状发射药的表面性能参数,采用接触角测量仪测量了粒状发射药在不同实验操作条件下的接触角,讨论了躺滴法测量发射药接触角操作过程中测试面的选取、测试面的处理方式、所用液滴体积、液滴与发射药测试面的接触时间等因素对接触角测定值的影响。依据实测数据确定了较为稳定的实验操作条件:用磨平的粒状发射药侧面作为接触角测试面,对测试面采用细砂纸打磨后再用丙酮擦拭、晾干的处理方式,所用液滴体积不大于1μL,取液滴与测试面的接触时间为8s时的接触角值作为测试结果。     

发射药燃烧转爆轰的试验研究

为研究发射药燃烧转爆轰特性及其影响因素,采用联合国危险分级试验中燃烧转爆轰试验方法对单、双、三基以及不同药型的发射药进行燃烧转爆轰试验。结果表明,在管厚4mm弱约束条件下,只有三基小粒发射药发生爆轰,在管厚9mm强约束条件下,6/7双基药、6/7叠氮发射药、6/7三基药以及三基小粒药发生爆轰。发射药配方中添加硝化甘油(NG)、叠氮硝胺(DA)和黑索金(RDX)以及减小药型尺寸,可增强发射药的燃烧转爆轰能力,同时,提高壳体约束强度更易发生燃烧转爆轰。     

EI发射药的燃烧特性

为研究EI发射药的燃烧性能,基于EI发射药的制备过程及药形结构特征,对EI发射药的浸渍层分布、燃烧过程中药型尺寸及能量特性的变化进行了理论分析和实验验证.建立了EI发射药的燃速计算数学模型.制备了NG浸渍量分别为10％和15％的EI-1和EI-2样品.进行了密闭爆发器试验、显微切片照相.结果表明,NG浸渍量为15％时,火药力提高了10.14％,浸渍深度为0.168 mm;根据实验数据计算EI发射药的u-p曲线,150 MPa前EI发射药的燃速高于单基发射药,在150 MPa后两者重合;由L-B曲线知EI-2发射药的燃烧渐增性较好.只要NG浸渍量和聚酯浸渍量配比合适,EI发射药的火药力和燃烧渐增性在一定范围内可以同步增加.     

由密闭爆发器实验数据分析变燃速发射药的燃烧渐增性

为进一步研究变燃速发射药的燃烧渐增性,提出了一种利用密闭爆发器实验数据描述发射药能量释放规律的数学物理模型.通过密闭爆发器实验,研究了一种中心开孔式双层硝胺变燃速发射药试样的燃烧渐增性.结果表明,所提出的数学物理模型可以用来定量地判断发射药燃烧的渐增性强弱;所研制的硝胺发射药显示出了渐增性燃烧的特点,并且可以通过调节配方和药型尺寸,达到调节控制其燃烧渐增性的效果.     

双基发射药热碎片传导点火实验及影响因素

为研究发射药在高温碎片作用下的点火和燃烧行为,选热钢材圆柱体作模拟碎片,模拟高温碎片作用于发射药的点火和燃烧过程,建立了用于发射药热碎片传导点火的实验装置,确定了在热碎片作用下易损性的表征参数,研究了双基发射药在热碎片作用下的点火和燃烧行为。结果表明,碎片温度、碎片尺寸、药型尺寸及样品环境条件是影响同一配方发射药热碎片传导点火的主要因素。     

双层管状变燃速发射药的燃气生成规律

为建立气体生成猛度Г与已燃发射药质量分数ψ的理论表达式,对双层管状变燃速发射药的燃气生成规律进行了理论分析。在服从几何燃烧定律的条件下,以双层管状药的初始药形尺寸及内外层药的燃速比、密度比为基本变量,推导出变燃速发射药的Г-ψ表达式,得出发挥双层变燃速管状药渐增性燃烧特点所需的临界长径比。通过Г-ψ计算曲线,说明这种发射药的内径、长径比及燃速比影响其燃气生成规律。结果表明,当双层管状发射药的初始药形尺寸及内外层药的燃速比取值适当时,会出现前期为渐增性燃烧、中后期有一个Г值的阶跃情况。     

智能化万用压力及三维流场测量系统开发

介绍了近年来研制成的一种高精度、智能化的万用压力及三维流场测量系统。该系统由五孔探针、差压传感器、专用高速ＡＤ－ ＤＡ 接口、ＰＣ微机及配套软件包构成,采用全菜单提示选择工作方式,使流场测量成为简单、方便、快速、高精度的智能化测量过程。实际测试应用证明了其优良特性。     

Novel burning rate measurement technique for solid propellant by means of ultrasonics

A novel burning rate measurement technique for solid propellants using ultrasonics has been developed. Ultrasound is applied to the burning surface of the end-burning propellant grain from the bulk side, and the reflected wave, which is frequency-shifted by the Doppler effect, is analyzed with a wavelet technique. This method enables us to get the instantaneous linear burning rate and, thus, can be a strong tool for the instability study of solid propellants. The wavelet method is also favorable for the identification of the reflected signal from the burning surface even if the signal intensity becomes very low and indistinguishable from white noise with normal measuring techniques. Efforts have also been paid to eliminate the coupling material between the ultrasonic probe and the propellant grain to simulate the real situation of rocket motors. An oscillation deadener circuit has been successfully employed to reduce strong multi-deflection signals within a metallic plate between the probe and the propellant grain. With these two improvements, it becomes possible to detect and process the signals in longer propellant grains in the actual solid rocket motor situations.     

火炸药药柱撞击感度试验装置及方法

为了提高火炸药药柱撞击感度测试的试验手段,建立了一套新的炸药药柱撞击感度测试系统,并对系统的主要技术指标进行了验证。设计了试验方法,对不同成型炸药药柱和不同尺寸的推进剂进行了撞击试验。结果表明,试验结果气体检测判定法明显好于传统的方法,药粉与药柱由于结构的不同,试验结果也不完全一致,即使相同种类的药由于尺寸不同也可能带来结果的差异。     

Measurement and Analysis of the Burning Rate of HAN‐Based Liquid Propellants

A new device for measuring the linear burning rate of liquid propellants at high pressures is reported. High‐pressure environments were generated by the combustion of solid propellants. The coated propellants, which burn progressively, were introduced to maintain the approximate constant‐pressure environments. By use of ion probe transducers, measurements were made of the spread velocity of the flame surface, i.e. the apparent linear burning rate of the HAN‐based liquid propellant LP1846 (HAN =hydroxylammonium nitrate) was measured quantitatively at pressures from 6 to 28 MPa. The results show that it follows the exponential burning rate law. The burning rate coefficient and exponent were fitted by least‐squares methods. Based on the experiment, a simplified model of the linear burning rate of HAN‐based liquid propellants at high pressures was developed. The numerical simulation is found to be in good agreement with the experimental data.     

Laser technique for determining solid propellant transient burning rates during oscillatory combustion

The laser technique was developed for measurement of transient burning rates of solid propellant during oscillatory combustion. the design and operation of the system are discussed. A high pressure window bomb was used for the combustion chamber. A modulating disk was used to induce the pressure oscillation above the combustion bomb. The oscillatory frequency was controlled easily with selecting the rotating velocity of the disk. Test results with AP/PS propellants, were in agreement with the results of previous techniques.     

21世纪先进发射药(2):低敏感高能发射药--新配方、装药、点火和理论模拟技术

研究开发低敏感高能发射药必将成为2l世纪发射药及其装药发展的趋势。讨论和分析了低敏感高能发射药的新配方、装药及点火设计、理论模拟等方面的最新研究进展和成果，展现了新一代先进发射药的优异性能。     

推进剂组分相容性研究方法

相容性是评价推进剂贮存安定性与使用可靠性的一项重要指标。概述相容性的定义、理论判据、实验和理论研究方法,重点综述测定多组分体系相容性的方法和改善推进剂组分内共混物相容性的方法。     

Chemical Analysis of Aluminum as a Propellant Ingredient and Determination of Aluminum and Aluminum Nitride in Condensed Combustion Products

A brief survey of typical problems in the analysis of aluminum powder in aluminized solid propellants and in analysis of condensed combustion products of these propellants was carried out. Recommendations for applying the versions developed by the authors of the known methods are given. The permanganatometric variant of the titrimetric method was found suitable for most tasks concerning the measuring of the metallic/unburned aluminum. The determination of aluminum nitride in combustion products using the combination of chemical and X‐ray diffraction methods was described and illustrated by results obtained from condensed combustion products of propellant formulations containing highly active ultrafine aluminum powder. Even for this formulation the content of aluminum nitride in the final condensed combustion products was found to be negligibly small independently of the nature of the gas (argon or nitrogen) used for bomb pressurization.     

Roles of the Interphase Stiffness and Percolation on the Behavior of Solid Propellants

Atomic force microscopy has provided access to local moduli for propellants prepared with bonding agents, which create a stiffness gradient in the matrix producing a stiffer interphase surrounding the fillers. The reinforcing impact of the bonding agent appears up to some distance and interphase percolation is observed. In order to better understand the impact of bonding agents on the stress and strain at break of propellants, finite element simulations are performed. Two‐dimensional periodic cells containing randomly dispersed particles are considered, including both a cohesive zone model at the filler/matrix interface to account for possible debonding and an interphase that percolates or not. The influence of the interphase stiffness and of its percolation, on the stress and strain at break of the model propellants are evaluated through the use of a microstructure‐based failure criterion.     

A New Method Rapidly Measuring Nitroglycerin in the coating of the rocket propellant

In this paper an application of thermogravimetric-derivative thermogravimetric analysis (TG-DTG) to the measurement of the nitroglycerin (NG) in thc coating of the rocket propellant was developed. In comparisons with gas chromatography (GC) and weight method (WM), TG-DTC has been confirmed to he even more available to measure rapidly migration of NG in thc coating. The new method is accurate to within ± 0.5% and its standard deviation is O.1. The method is of actual significance in respect of thc investigation of the migration regularity of plasticizer, the selection for coating materials and the prediction of service life of the solid propellants.