METHOD FOR MAKING EXPLOSIVE CHARGES BY FILTERING LIQUID EXPLOSIVE（英）

The process of sensitive explosive charges making is dangerous and re-quires complicated technological equipment.In multi-component composition making,different mixing devices necessary cause mechanical effects on the processed material,which can lead to ignition and even to explosion.In St-Petersburg Technological Insti-tute a new method which is free of these shortcomings is worked out for making explo-sive charge of powerful crystal explosive with melt explosive or liquid polymer.     

The Application of Erosive Burning to Propellant Charge Interior Ballistics

Erosive burning is a common burning phenomenon of the gunpowder with inner holes. The actual combustion law of the gunpowder with inner holes can be changed by erosive burning. Pressure difference between the inner and the outer of hole caused by loading density variation of the propellant charge makes erosive burning occur at inner holes during in-bore burning. The effect of erosive burning on burning speed of the propellant is studied by using the effects of flow rate, heat transfer and erosion of the combustion gas in inner holes on burlaing rate. The mathematic model of erosive burning of the propellant is established. The effects of the factors such as loading density, inner hole size and grain length on erosive burning and interior ballistic performance are analyzed . The method to improve the bore pressure for small charge mass and small firing range by erosive burning is proposed.     

Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate （TEGDN） （TEGDN propellants） to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.     

Burning characteristics of microcellular combustible objects

Microcellular combustible objects for application of combustible case, caseless ammunition or combustible detonator-holding tubes are fabricated through one-step foaming process, in which supercritical CO2 is used as foaming agent. The formulations consist of inert polymer binder and ultra fine RDX. For the inner porous structures of microcellular combustible objects, the cell sizes present a unimodal or bimodal distribution by adjusting the foaming conditions. Closed bomb test is to investigate the influence of both porous structure style and RDX content on burning behavior. The sample with bimodal distribution of cell sizes burns faster than that with unimodal distribution, and the concentration of RDX can influence the burning characteristics in a positive manner. In addition, the translation of laminar burning to convective burning is determined by burning rate versus pressure curves of samples at two different loading densities, and the resulting transition pressure is 30 MPa. Moreover, the samples with bigger sample size present higher burning rate, resulting in providing deeper convective depth. Dynamic vivacity of samples is also studied. The results show that the vivacity increases with RDX content and varies with inner structure.     

Application of Space-time Conservation Element and Solution Element Method in Intake and Exhaust Flows of High Power Density Diesel Engine

A one-dimensional pipe flow model of single-cylinder diesel engine is established to investigate the intake and exhaust flow characteristics of diesel engine in the condition of high power density （HPD）. A space-time conservation element and solution element （CE/SE） method is used to derive the discrete equations of the partial differential equation for the intake and exhaust systems. The performance parameters of diesel engine with speed of 2100 r/min are simulated. The simulated results are in accordance with the experimental data. The effect of increased power density on charging coefficient is analyzed using a validated model. The results show that the charging coefficient is slowly improved with the increase in intake pressure, and is obviously reduced with the increase in engine speed.     

Study on Random Initiation Phenomenon for Sympathetic Detonation of Explosive

It is important to understand the characteristics of explosive sympathetic detonation for explosive safety. Sympathetic reaction test of GIlL （RDX/A1/Binder） explosive charges with shell are conducted. A model of the sympathetic reaction test is established. The elements-apart method and nodes random-failure method are used in the model to desctibe the expression progress of shell expanding and the randomly forming process of fragments. Random detonation phenomena of acceptor charge are simulated.     

Study of simple plane wave generator with an air-metal barrier

Plane wave generators （PWGs） are used to accelerate flyer plates to high velocities with their generated plane waves, which are widely used in the test of dynamic properties of materials. The traditional PWG is composed of two explosives with different detonation velocities. It is difficult to implement the related fabrication processes and control the generated waves due to its complicated structures. A simple plane wave generator is presented in this paper, which is composed of two identical cylindrical high explosive （HE） charges and an air-metal barrier. A theoretical model was established based on two different paths of the propagation of detonation waves, based on which the size of air-metal barrier was calculated for a given charge. The corresponding numerical simulations were also carried out by AUTODYN-2D based on the calculated results, which were used to compare with the theoretical calculations. A detonation wave with a flatness of 0.039 μs within the range of 70-percent diameter of the main charge was obtained through the simulations.     

Simulation of Aviation Kerosene Combustion in Dual-mode Scramjet Combustor

Supersonic combustion of aviation kerosene is investigated under the flight conditions of Mach number 5 and fuel-air equivalence ratio 0. 551. The trajectories of the fuel droplets and the heat/mass transfer between them are simulated by means of discrete phase model （DPM）. The k-ω model is chosen for turbulence closure and the non-premixed probability density function （PDF） approach is used to calculate the turbulence-chemistry interaction. The calculated wall static pressure and the total pressure loss coefficient are very close to the experiment results. The strut and cavity devices significantly increase the combustion efficiency.     

Analysis of Micro-scale Flame Structure of AP/HTPB Base Bleed Propellant Combustion

A complex multiple flame stracture is formed dining the combustion of AP/HTPB base bleed propellant. The AP monopropellant flame is concentrated in a thin zone above the burning surface of AP mystal to maintain seK-sustained decomposition. Due to the low temperature near the burning surface, the diffusion between the decomposition products of AP and the pyrolysis products of HTPB occurs, and a partly pre-mixed diffusion flame stracture-leading edge flame （LEF） is formed. The effects of pressure, chemical reaction rate and AP particle size on diffusion flame structure in the ravage from 20 arm to 100 ann are discussed. The Peclet number increases from 6.64 at 20 ann to 21.91 at 100 ann when AP particle size is 140 μm. The high temperature zone is blown away from the burning surface because the convective transport rate increases with the increase in Peclet number. The chemical reaction rate is enhanced and the diffusion mixing is hlhibit ed as Damkolfler nunlber increases. The chemical heat release is more concentrated axed the chemical reaction zone becomes nan＇ow when Damkolfler nunlber changes from 330 at 20 ann to 4700 at 100 atm. When AP particle diameter is decreased to 60 μm, the diffusion time scale is reduced due to the reduced diffusion length scale. So the diffusion mLxing is enhanced a more pre-mixed flame is formed. The burning rate increases because the more pre-mixed     

Experimental Study of RF-excited Diffusion Cooled Off-axis Unstable Resonator with High Frequency Modulation in a Waveguide CO2 Laser

The experimental study of the laser beam parameters of the pulse repetitive RF-excited diffusion cooled waveguide CO2 laser are presented. The measurements are carried out for the pumping pulse duration of 100 μs and pulse repetitive rates 5 - 14 kHz. The average power density delivered to the active medium is 76 W/cm^3. Three types of the pulses, namely the square, the sine and the triangular ones have been applied at the input as pumping pulses and their effects on the output power and the delay time have been studied. The output power of the radiation versus input power, pressure of the laser gas mixture and modulation frequency has been investigated. The results indicate that the output peak power for the three types of pulses increases with increase of the pressure of the laser gas mixture and with the input power where as it decreases with the repetition frequency. The delay time of the output pulse decreases with the increase of the repetition frequency and input power, where as it increases with the increase of the pressure of the laser gas mixture. The behavior of the output power and the delay time with duty cycle for square pulse has also been investigated.     

含偶氮四唑胍的改性双基推进剂性能（英）

采用浇铸工艺制备了含偶氮四唑胍盐(GZT)的RDX-CMDB推进剂,系统地研究了含GZT的RDX-CMDB推进剂的能量性能、燃烧性能和热安全性能等。理论计算和实验研究结果表明:RDX-CMDB推进剂的比冲、爆热和燃温随GZT含量的增加而降低,15%的GZT使推进剂的比冲降低了29.2 s,爆热降低了1248 kJ.kg-1,燃烧温度降低了800 K;RDX-CMDB推进剂的成气量随GZT含量的增加而增加,15%的GZT使成气量增加了10.73 mol.kg-1;GZT使RDX-CMDB推进剂燃烧更完全,且高温下(200℃以上)更容易燃爆,但对推进剂在100℃下的热安全性能无明显影响;对于不含有机铅铜催化剂的RDX-CMDB推进剂,G ZT使推进剂燃速升高,压强指数降低,15%的G ZT使推进剂7 MPa下的燃速提高了1 mm.s-1,使7～10 MPa间的压力指数由0.86降低到0.70;对于含有机铅铜催化剂的RD X-CMD B推进剂,G ZT使推进剂的压力指数升高,燃速降低,15%的G ZT使推进剂7 MPa下的燃速下降了3 mm.s-1,7～10 MPa间的压力指数由0.47上升到0.69。热行为研究表明,GZT表现出一单独的分解失重过程。     

铝薄膜含量对RDX基铝薄膜炸药水下爆炸性能影响

将传统含铝炸药中的铝粉用铝薄膜代替,得到铝薄膜炸药。用水下爆炸对比实验得到了铝薄膜含量为10%~40%的混合炸药与黑索今(RDX)在不同位置的压力-时程曲线。经过分析与计算得到了不同铝薄膜含量混合炸药的压力峰值、冲量、比冲击波能、比气泡能。结果表明:铝薄膜含量为10%时,铝薄膜炸药冲击波冲量相对于RDX提高了9%~9.5%,铝薄膜炸药比冲击波能相对于RDX提高了9%~12%。铝含量对铝薄膜炸药水下爆炸性能的影响不同于传统含铝炸药,主要由铝薄膜炸药的药柱结构与铝薄膜反应程度引起。     

封闭空间内水层对爆炸载荷特性影响的实验研究

采用球对称爆炸装置,在球形容器中开展了炸药与水之间有空气间隙（层）的置水爆炸实验,根据实测的激波走时、压力和冲量等数据,对容器内置水爆炸载荷形成机制进行了分析,并探讨了爆炸过程中空气间隙与爆轰产物和水之间的作用机理。结果表明：置水爆炸时容器内壁受到的载荷主要包括幅值较低的前导空气冲击波和雾状水滴的持续撞击作用,有空气间隙的置水爆炸可以降低反射压力、准静态压力和冲量,空气间隙有利于水对爆炸载荷的消减效果。     

钢筋混凝土端面重墙结构的抗爆性能规律

为研究钢筋混凝土端面重墙结构在爆炸冲击波下的抗爆性能,依据最大TNT当量为300 kg的现场试验,对D1、D2、D33种不同构型端面重墙的损伤破坏规律进行数值模拟研究.基于LS-DYNA有限元分析软件,建立流体和固体耦合数值模型,计算得到3种重墙房屋结构在爆炸冲击波作用下的破坏形态,并利用试验结果校正模型参数.进一步利...     

黑索今基含铝炸药的铝氧比对爆轰性能及其水下爆炸性能的影响

为了分析铝氧比对爆压和爆速的影响规律,采用试验方法测定了黑索今（RDX）基含铝炸药的爆轰参数,应用KHT程序计算分析了试验测试结果;针对RDX基含铝炸药,进行了1kg柱形装药水下4.7 m爆炸试验,测量了距爆心1～3m处的冲击波压力峰值与气泡脉动周期,拟合得到了冲击波压力峰值与衰减时间常数的相似律系数。研究结果表明：RDX基含铝炸药的爆压和爆速随铝氧比的增加呈现线性减小变化,爆热在铝氧比为0.997时达到最大值;当铝氧比为0.366时,冲击波压力峰值与冲击波能达到最大值;当铝氧比为0.633时,冲击波冲量与冲击波能量密度达到最大值;当铝氧比为0.997时,气泡第一次脉动周期与半径达到最大值。     

PBT/A3 基RDX 含铝炸药爆炸能量特性研究

为掌握PBT/A3 粘结剂体系对含铝炸药爆炸能量的影响特性,以PBT/A3 粘结剂体系为研究对象,复合 RDX 和Al 粉设计PBT/A3 基RDX 含铝炸药配方。测试炸药复合体系密度、爆速、爆热等性能,并与相同条件HTPB 基RDX 含铝炸药进行对比,探讨PBT/A3 粘结剂对炸药密度及爆炸本征能量爆速和爆热影响;开展PBT/A3 基含铝 炸药冲击波超压性能测试,对其近/远场冲击波能量释放特性进行分析和讨论。研究结果表明：较于HTPB 基RDX 含铝炸药,PBT/A3 粘结剂对复合体系装药密度提升9.1%,爆速和爆热分别提升1.45%和11.47%,能量密度提升较 为明显;PBT/A3 基炸药近场超压当量为1.6 倍,远场超压当量为1.69 倍,PBT/A3 含能粘结剂体系的引入改善了复 合体系氧平衡,有利于Al 粉充分燃烧提高其远场能量释放。     

带壳装药热爆炸冲击波超压测量及分析

冲击波压力是评估炸药爆炸效应的重要参数,冲击波压力的特征与装药形式和起爆方式密切相关.介绍了带壳装药热爆炸模式下的装药周围空气中的冲击波超压的测量方法和测量结果,并结合爆室结构,对结果进行了深入分析.带壳装药爆炸时,由于电动效应及爆炸产物和壳体之间的摩擦,会产生电磁辐射,且电磁辐射信号持续时间和复杂程度与裸露炸药爆炸时...     

密闭空间内六硝基六氮杂异伍兹烷基复合炸药能量释放特性

为研究密闭空间内六硝基六氮杂异伍兹烷(CL-20)基复合炸药爆炸能量释放特性,实验测试了药氧比为0.35～1.00炸药样品内爆产生的准静态压力.基于理想气体绝热模型和铝粒子气化燃烧方程,计算分析了不同药氧比样品爆炸的能量释放过程,应用非线性有限元AUTODYN软件模拟了不同药氧比炸药样品密闭空间内爆炸的作用过程.研究结...     

考虑后燃烧效应的TNT空气中爆炸的数值模拟

采用AUTODYN软件对TNT在空气中爆炸进行了数值计算,在计算模型中考虑了负氧平衡炸药的后燃烧效应,并将峰值超压、比冲量、正压作用时间计算结果与相似律公式计算值以及Baker测试数据进行了对比,指出Brode公式计算出的炸药附近空气冲击波峰值超压明显偏大,可能是将爆轰产物造成的峰值超压误认为空气冲击波峰值超压所致.     

硅系延期药的共沉淀法制备及其性能

采用共沉淀法和手工混药法制备了硅系延期药,通过扫描电子显微镜(SEM)、能谱分析(EDS)及X-射线粉末衍射(XRD)分析显示:在共沉淀过程中有BaSO4和(BaPb)SO4的生成,并实现了对硅粉Si和Pb3O4的部分包覆。在60 MPa压力下将一定量延期药和适量点火药装入外径为5 mm的铁制延期管内,采用光电法对延期时间进行测试,结果表明:共沉淀法制备的延期药的平均燃速为1.25 mm.s-1,手工混合制备的延期药的平均燃速为1.41 mm.s-1;共沉淀法制备的延期药的延期精度明显高于手工混制的,前者燃速的标准差0.073,后者的为0.25。