固态燃料空气炸药空爆实验研究

通过四组无约束固态燃料空气炸药(FAE)装置与等质量的TNT在野外开放空间的一次起爆对比实验,测得了不同配方组份FAE装置在不同距离的爆炸超压分布,FAE装置峰值超压比相同距离的TNT高1.14~1.6倍;并运用空气冲击波峰值超压公式计算出了FAE的等效爆炸TNT当量随距离的变化关系,在爆炸场边缘区,FAE装置爆炸当量达到了3.88倍TNT当量;通过高速摄影的图片得到了爆炸产生火球的持续时间和最大作用范围,与等质量TNT爆炸火球相比,FAE的优势明显;运用粉尘爆炸下极限浓度估算了云雾爆轰区半径,并分析了测量到的固态FAE爆炸场的压力分布单调衰减的原因;建议在保持超压不变的情况下,把提高爆温作为提高FAE爆炸性能的主要途径。     

Hydrodynamics of explosion: models and software for modeling explosions and estimation of their consequences

Physical and hydrodynamic processes accompanying explosions of condensed explosives and fuel–air mixtures have been considered. Wide-range equations of state of explosion products and air have been used. A physical model and a program code based on the gas dynamics equations in the Lagrangian form have been developed for modeling one-dimensional hydrodynamic processes in the near zone of explosion. This firmware forms the basis for estimation of explosion consequences. The described model has shown its working efficiency within a wide range of explosion energies and environmental conditions.     

新型发射药爆炸TNT当量系数的实验研究

TNT当量系数是危险品工程抗爆设计和安全距离确定的重要依据。为确定H1和H2两种新型高能发射药的TNT当量系数,分别开展了10 kg TNT和新型发射药的空气自由场静爆实验。基于修正的当量系数计算方法和测量得到的不同爆心距离处冲击波超压时程曲线,确定了不同比例距离处两种高能发射药的超压和比冲量TNT当量系数。研究结果表明,发射药爆炸产生的冲击波传播规律与TNT炸药爆炸产生的冲击波传播规律相同,符合爆炸相似律,相同质量发射药爆炸产生的冲击波超压和比冲量都显著高于TNT的。随着比例距离的增大,H1的超压当量系数先增大后减小,最大值为1.34;H2的超压当量系数逐渐减小,最大值为1.26。两种新型发射药的比冲量TNT当量系数均随比例距离的增大先减小后增大,H2的比冲量TNT当量系数大于H1的,最大值为1.38。本文中修正的计算方法能更准确计算被试样品的TNT当量系数,实验结果可为提高抗爆结构安全性设计提供参考。     

不同装药战斗部壳体对水中兵器的爆炸威力

通过对裸炸药和带壳战斗部在无限水域中水下爆炸的实验研究,对比分析了炸药的冲击波峰值压力、比冲击波能、比气泡能、总比能量及相对比总能量等爆炸特性参数。结果表明:不同装药爆炸后峰值压力从大到小分别是热塑梯黑铝、熔梯黑铝、复合PBX、TNT,其他对比参数从大到小分别是复合PBX、熔梯黑铝、热塑梯黑铝、TNT;带壳战斗部爆炸后比冲击波能、比气泡能、总比能量相对裸炸药均有不同程度的下降,其中总比能量分别比裸炸药减少25%、21%、15%和15%;战斗部壳体对水中兵器爆炸的比冲击波能、比气泡能及总比能量的影响较为显著。因此,研究水中兵器爆炸威力必须考虑战斗部壳体因素,不能简化。研究成果对于战斗部水下爆炸威力考核有一定的借鉴意义。     

Numerical models for afterburning of TNT detonation products in air

Afterburning occurs when fuel-rich explosive detonation products react with oxygen in the surrounding atmosphere. This energy release can further contribute to the air blast, resulting in a more severe explosion hazard particularly in confined scenarios. The primary objective of this study was to investigate the influence of the products equation of state (EOS) on the prediction of the efficiency of trinitrotoluene (TNT) afterburning and the times of arrival of reverberating shock waves in a closed chamber. A new EOS is proposed, denoted the Afterburning (AB) EOS. This EOS employs the JWL EOS in the high pressure regime, transitioning to a Variable-Gamma (VG) EOS at lower pressures. Simulations of three TNT charges suspended in a $26\,\hbox {m}^3$ explosion chamber were performed. When compared to numerical results using existing methods, it was determined that the Afterburning EOS delays the shock arrival times giving better agreement with the experimental measurements in the early to mid time. In the late time, the Afterburning EOS roughly halved the error between the experimental measurements and results obtained using existing methods. Use of the Afterburning EOS for products with the Variable-Gamma EOS for the surrounding air further significantly improved results, both in the transient solution and the quasi-static pressure. This final combination of EOS and mixture model is recommended for future studies involving afterburning explosives, particularly those in partial and full confinement.     

Secondary shock features for large surface explosions: results from the Sayarim Military Range,Israel and other experiments

A series of surface explosions was designed and conducted by the Geophysical Institute of Israel at the Sayarim Military Range in the Negev desert, including two large-scale explosions: approx. 82 tons of high explosives in 2009, and approx. 100 tons of low-grade ANFO explosives in 2011. The main goal of the explosions was to provide large controlled sources for calibration of global infrasound stations designated for monitoring nuclear tests; however, the geophysical experiment also provided valuable observations for shock wave research. High-pressure gauges were deployed at distances between 100 and 600 m to record air blast properties and to provide reliable estimation of the true charge yield compared to the design value. Secondary shock phenomena were clearly observed at all near-source gauges as characteristic shock wave shapes. Secondary shocks were also observed at numerous seismic and acoustic sensors deployed in the range 0.3–20 km as acoustic phases. Empirical relationships for standard air blast parameters (peak pressure and impulse) and for a new parameter called secondary shock time delay, as a function of distance, were established and analyzed. The standard parameters, scaled by the cubic root of the estimated TNT yield, were found to be consistent for all analyzed explosions. However, the scaled secondary shock delays were clearly separated for the 2009 and 2011 explosions, thus demonstrating dependence on the explosive type. Additionally, air blast records from other experiments were used to extend the charge and distance ranges for the secondary shock observation, and showed consistency with the Sayarim data. Analysis and interpretation of observed features of the secondary shock phenomenon are proposed and a new empirical relationship of scaled secondary shock delay versus scaled distance is established. The results suggest that the secondary shock delay can be used as a new additional waveform feature for simple and cost-effective explosive yield estimation.     

温压炸药在野外近地空爆中的冲击波规律

为了研究温压炸药在敞开空间爆炸中冲击波的规律,选取典型温压炸药制成不同量级的裸药柱进行野外近地空爆实验,同时用TNT进行对比实验,获取温压炸药与TNT的冲击波参数并拟合得到相似律公式。结果表明,温压炸药的冲击波超压峰值在中远场略高于TNT;在相同对比距离处,温压炸药的比冲量明显高于TNT,在对比距离小于2 m/kg1/3的近场,温压炸药的比冲量达到TNT的2倍。引入超压-比冲量曲线描述冲击波特征,表明当超压峰值相同时,温压炸药比冲量更大, 超压峰值在20~50 kPa的中度以下毁伤范围时,温压炸药的比冲量比TNT高40%~60%,可产生更严重的毁伤效应。冲量是爆炸冲击波的重要毁伤元素,应建立与冲量有关的方法评价温压炸药的威力。     

Numerical modeling the dynamics of flow in explosion above a surface

The hydrodynamics of processes occurring in explosion of condensed explosives in air is considered. The physical model, computation technique, and results of simulation of a two-dimensional hydrodynamic flow arising in explosion of cylindrical charges are discussed. In this case, the explosions are considered at some distance above the ground. To close the gas-dynamics equations, the Jones–Wilkins–Lee equation of state is used. The results of calculation allow one to obtain a detailed space–time pattern of the arising flow and to study the origination, propagation, and subsequent attenuation of shock waves. Cylindrical charges of the same mass but with different diameter-to-length ratios are considered. It is shown that the charge shape can render essential influence on dynamics of flow and the parameters of shock waves (in the near and medium fields of explosion).     

温压炸药的爆炸温度

根据温压炸药的爆炸特性,采用红外热成像仪研究温压炸药的爆炸温度。通过对实验结果的分析发现,与等量TNT相比,温压炸药爆炸云团温度较高,高温持续时间是TNT的2~5倍,高温云团体积可达TNT的2~10倍,体现了温压炸药相对于传统高能炸药的温度场优势。药剂被引发后所形成的高温环境,足以维持其中铝粉的后续快速燃烧反应,从而为增强爆炸冲击波提供帮助。     

触、近水面爆炸自由场冲击波特性的试验研究

本文通过药量为0.05kg至32kgTNT的触、近水面化爆试验,介绍了空中、水中冲击波的测量方法和传播特性,并总结出一些计算冲击波参数的实用的经验公式。     

压装TNT的SDDT特性研究

本文报告厂将水箱技术同改型隔板试验结合起来研究凝聚炸药由冲击波经爆燃向爆轰转变(SDDT)的方法。实测了压装TNT(装药密度1.615g/cm~3)的SDDT曲线,并确定了其燃烧阈值和爆轰阈值(分别为2.1GPa和2.5-3.0GPa)。按照流体动力学特征线法计算了不同强度起爆冲击波作用下在炸药中形成的一系列冲击波、爆燃波和爆轰波的剖面,这些剖面反映了炸药SDDT的基本特征。所取得的信息对于炸药的实际应用和对冲击波起爆的深入研究均有价值。     

水及盛水容器对近距离爆炸载荷影响的实验研究

为研究用水包围炸药的方式对爆炸载荷的作用机理,在两端开口的钢筒内进行了水直接包覆炸药的爆炸实验,利用光纤位移干涉仪获取了钢筒外壁的径向速度和动态变形。结果表明:不同于无水爆炸,爆轰产物通过水的“裂缝”在空气中形成冲击波,造成该冲击波出现时间更晚、强度更低、持续时间更长,并要求相应的数值模拟采用二维以上的计算模型;盛水结构的材料密度越低、厚度越小对爆炸载荷的影响越小。     

Studies of the TNT equivalence of silver azide charges

Schlieren photographs and shadowgrams have been evaluated to provide the radius-time histories of the shocks generated by explosions of silver azide charges with masses in the milligram range. Series of photographs of the flow field produced by a single explosion were obtained with an image converter camera, to yield a time history of the shock trajectory. These data were used to determine the shock Mach number and subsequently the peak hydrostatic overpressure as a function of radius. The pressure-radius profile was compared with that from a unit charge of TNT to determine the TNT equivalence of silver azide as a function of peak pressure and of distance from the centre of a silver azide charge. The shock radius and time were also determined from single-shot visualizations of silver azide explosions. A new method of analysis was developed so that the charge mass and the TNT equivalence of an explosion could be derived from such a single radius-time measurement. The TNT equivalence factor for silver azide was shown to vary from 0.3 to 1.4, depending on the distance from the centre of the explosion. This agrees well with the generally reported equivalence factor of about 0.4 (Baker et al. 1983), which was probably based on the chemical composition of the material. Procedures are described by which the TNT equivalence factor can be calculated at any specified distance from a silver azide charge of known mass, or from a measurement of the shock radius and time, even when the charge mass is not known. This factor can then be used to determine the physical properties of the TNT blast wave which best describe those from the silver azide charge at the specified distance. A further result of these studies was that the scaling laws for blast waves, whose validity has been verified for charge masses ranging from a few grams to hundreds of tons, i.e., for charge masses varying over more than nine orders of magnitude, also apply for charges with masses of the order of one milligram.Received: 7 April 2003, Accepted: 1 July 2003, Published online: 5 August 2003     

Application of background oriented schlieren for quantitative measurements of shock waves from explosions

This paper describes application of a background oriented schlieren technique in order to obtain quantitative measurements of shock waves from explosions by processing high speed digital video recordings. The technique is illustrated by an analysis of two explosions, a high explosive test and a hydrogen gas explosion test. The visualization of the shock front is utilized to calculate the shock Mach number, leading to a predicted shock front pressure. For high explosives the method agreed quite well with a standard curve for side-on shock pressures. In the case of the gas explosion test we can also show that the shock front is non-spherical. It should be possible to develop this technique to investigate external blast waves and external explosions from vented gas explosions in more details. This paper is based on work that was presented at the 21th International Colloquium on the Dynamics of Explosions and Reactive Systems, Poitiers, France, July 23–27, 2007.     

不同介质地下爆炸的地震耦合效应

对黄土、砂砾石和花岗岩等几种不同介质中的地下爆炸实验进行了地表速度测量,利用实测数据 获得爆炸源频谱以及以折合速度势低频稳态值表示的地震耦合强度。实验结果表明,对于相同当量、相当比 例埋深下的地下爆炸,地震耦合强度和源区介质特性有着强烈的依赖关系,其中介质强度是影响地震耦合效 率的最主要因素,而介质的干孔隙率和水饱和度也是影响地震耦合效率的重要因素。考察了M.D.Denny等 提出的经验公式在估算100kg级当量地下爆炸地震耦合强度的适用性和局限性。     

温压炸药爆炸抛撒的运动规律

采用高速运动分析系统观察了高能炸药、含铝炸药和温压炸药爆炸产物抛撒的过程;比较了这3种炸药的爆炸产物抛撒运动及后燃特点,通过比较直观地观察到温压炸药爆炸和后燃2个过程,以及后燃火球的成长历程;根据实验结果确定了温压炸药爆炸产物抛撒半径随时间变化的数学表达式。     

CL-20基炸药水中爆炸气泡脉动实验研究

为研究CL-20基炸药、CL-20基含铝炸药水下爆炸气泡脉动情况,在2 m×2 m×2 m的实验水箱中开展小当量实验,采用高速摄影技术,得到炸药水中爆炸冲击波传播曲线,同时清晰地观测到气泡的产生、膨胀和收缩过程。拟合得到气泡脉动过程中气泡半径、速度、加速度对时间的变化曲线,对比分析了CL-20含铝与非含铝炸药水下爆炸气泡脉动规律。在实验条件下,首次直观地拍摄到CL-20含铝炸药水下爆炸的二次反应放热现象。实验表明:CL-20基含铝炸药的气泡半径、脉动周期都明显升高,半径增大13.7%,周期增大6.9%;冲击波峰值压力略有下降;水下爆炸测试技术以及高速摄影技术是研究观测含铝炸药二次反应的有效手段。     

固态燃料小型FAE装置空中爆炸场效应分析

通过一次引爆固态复合粉尘燃料小型FAE装置与等质量TNT在自由空间的爆炸对比实验,获得了不同距离的峰值超压值,并运用粉尘爆炸下极限浓度对云雾爆轰区半径进行了估算。结果表明,固态燃料小型FAE装置空爆峰值超压分布规律不同于TNT,云雾爆轰区内的峰值超压不呈现单调减的特征,而是在有限范围内呈现波动趋势;云雾爆轰区外的峰值超压随距离增大迅速衰减,但固态燃料小型FAE装置的峰值超压大于相同距离处等质量的TNT。高速摄影观测结果显示,固态燃料小型FAE装置爆炸的化学反应持续时间大于等质量TNT。     

用水下卡片间隙试验法测定炸药冲击波感度

将炸药的水下爆炸能量测试方法与冲击波感度测试方法（小隔板法）相结合,研究了一种测试炸药冲击波感度的方法水下卡片间隙试验法,并用该方法得到了6种炸药冲击波感度的相对排序（从高到低）:炸药泰安、黑索金、8701、钝化黑索金、梯恩梯、膨化硝酸铵的冲击波感度依次降低,该试验结果与文献值、传统隔板试验结果一致,表明水下卡片间隙试验法的测试结果是可信的,水下卡片间隙试验法用于测定炸药冲击波感度是可行的,在一定程度上可代替传统的隔板试验法,此方法还可用于研究炸药装药密度对其冲击波感度的影响。     

Optical measurement and scaling of blasts from gram-range explosive charges

Laboratory-scale experiments with gram-range explosive charges are presented. Optical shadowgraphy and high-speed digital imaging are used to measure the explosive-driven shock-wave position as a function of time. From this, shock Mach number-versus-distance from the explosion center can be found. These data then yield the peak overpressure and duration, which are the key parameters in determining the potential damage from an explosion as well as the TNT equivalent of the explosive. Piezoelectric pressure gage measurements of overpressure duration at various distances from the explosive charges compare well with theoretical calculations. A scaling analysis yields an approach to relate the gram-range blast to a large-scale blast from the same or different explosives. This approach is particularly suited to determining the properties and behavior of exotic explosives like triacetone triperoxide (TATP). Results agree with previous observations that the concept of a single TNT equivalence value is inadequate to fully describe an explosive yield, rather TNT equivalence factor and overpressure duration should be presented as functions of radius.