Numerical simulation on the bomb case effects of non-ideal aluminized explosive

The detonation process of non-ideal explosives is influenced by the casing of the bomb. Non-ideal charges in the process of the explosion of live ammunition energy output mechanism and distribution ratio, the impact of the case on the explosion flow field, and other issues cannot be obtained through the existing theoretical analysis and testing techniques to obtain specific values. This paper establishes a “detonation+afterburning” energy output model to characterize the energy release characteristics of non-ideal charges, using step-by-step numerical simulation of the near and middle, and far fields of the explosion, and verify simulation results through experiments, quantitative analysis the case of a type of earth penetrator on the normal particle size (4 μm) and two times the normal particle size (8 μm) of non-ideal charges of aluminum powder explosion process. The results indicate that the presence of the casing enhances the energy output of aluminum powder with 4 μm by ≈5 %. When the particle size of aluminum powder is doubled, the maximum reaction rate and the peak of the shock wave are merely around 35 % and 75 %, respectively, compared to those of normal particle size. The detonation products, case fragments, and air constitute 49 %, 48 %, and 3 % of the overall explosion energy, respectively. The proportional equation of the conversion between the chemical energy of the explosion and the kinetic energy of the case fragments is obtained. These conclusions can provide data support for the design of non-ideal charge warheads, lethality assessment, and establishment of engineering protection standards.     

TNT装药水中爆炸的数值模拟

采用AUTODYN软件对不同起爆方式下TNT装药水中爆炸模型进行了数值计算,并对计算结果进行了实验验证.根据计算结果分析了中心起爆、端面中心起爆和端面面起爆情况下,在装药不同方位的水中冲击波压力峰值随距离的变化趋势.计算结果表明,端面起爆状态下,装药径向的冲击波压力峰值均大于端部;中心起爆状态下,一定距离处,装药端面的压力峰值大于径向.改变起爆方式,可以实现水中爆炸冲击波能量的定向增益,提高特定方位爆炸能量利用率.     

Numerical Modeling Evaluation of Underwater Energies

The underwater detonation of explosives has been modeled using the one-dimensional code SIN. Conditions for the modeling are carefully chosen so that equilibrium product isentropes calculated with BKW equation of state can be used with enough accuracy. The characteristics of the shock wave and gas bubble pulsation are used for the evaluation of underwater energies. Values of the shock wave and bubble parameters obtained, and of the shock and bubble energies, are compared with data available from literature for both ideal and non-ideal explosives. The modeling appears to be able to predict fairly accurately the underwater energies of explosives with quasi-ideal behavior, while it overestimates energies of non-ideal compositions, particularly the shock energy.     

含铝典型炸药爆轰参数计算研究

用途不同,对炸药的爆速、爆压、爆热要求不一样。准确、快速计算炸药的爆轰参数对于设计指定性能新型炸药和炸药的应用研究具有十分重要的意义。本文用不同的方法对含铝炸药的爆轰参数进行了计算,采用含铝炸药经验公式计算含铝炸药的爆速、ω-Г公式方法计算的爆压、盖斯定律计算爆热,较其他计算方法计算结果相对误差小。     

含铝炸药与理想炸药能量输出结构的数值模拟

采用AUTODYN计算软件,对含铝炸药与理想炸药水中爆炸能量输出结构进行了数值模拟,讨论了人工黏性对计算结果的影响,对冲击波压力历程进行了对比分析.结果表明,含铝炸药PBXN-105水中爆炸时由于铝粉的二次燃烧放热,能够在较远距离处保持较大的冲击波能,作功能力高于理想炸药PBX9010.含铝炸药水中爆炸能量输出结构的数值模拟可以为炸药的配方设计提供一定的依据.     

炸药水中爆炸规律的研究进展

通过对比炸药空中爆炸的特性,阐述了水中爆炸的显著特点,分析和总结了炸药水中爆炸规律的研究现状,包括水中爆炸冲击波理论研究、气泡脉动和目标对炸药水中爆炸的动态响应等,并根据已有的研究现状,提出了目前炸药水中爆炸机理的两大类研究热点和发展培势,即应重点进行炸药水中爆炸毁伤作用及水中爆炸载荷的能量输出结构研究,深入研究目标对于炸药水中爆炸近场能量输出结构的动态响应过程。附参考文献31篇。     

炸药爆炸能量的水中测试与分析

介绍了炸药爆炸能量的水中测试方法,对TNT和3种新设计的含铝炸药进行了水中爆炸的实验研究,比较了各炸药的爆炸性能.结果表明,发现冲击波峰值超压、冲量和冲击波能流密度等参数较好地符合爆炸相似律,得到了新配方各参数的爆炸相似律系数.计算了炸药的冲击波能和气泡能,并提出了计算爆炸总能量的方法.把实验测得的炸药的总能量与KHTR程序计算的爆热进行对比,二者符合得较好,说明了KHTR程序可用.     

Underwater detonation performance of the aluminum film explosive

A new aluminized explosive is proposed, and the approach is to replace the aluminum powder in the traditional aluminized explosive with an aluminum film. The purpose is not only to improve mechanical properties and lower the impact sensitivity of traditional aluminized explosives, but also to reduce environmental pollution in the aluminum particle production process. The pressure-time curves of the aluminum film explosive and RDX are measured in underwater explosion experiments. The peak pressure, impulse, shock wave energy, and bubble energy are obtained by analyzing the curves. The results of the study indicate that the peak pressure of the aluminum film explosive is lower than that of RDX. However, the aluminum film explosive maintains a high pressure for a longer period of time. The large amount of energy is found to liberate by subsequent reactions of the Al film with the primary detonation products. The increase in the explosion energy of the aluminum film explosive is based mainly on the increase in the bubble energy.     

淀粉-PLA复合材料拉伸性能的数值模拟

针对淀粉-PLA复合材料的微观结构,建立了球形粒子填充的简单立方体模型的八分之一胞体模型,并使用有限元方法有效地模拟了低质量分数时淀粉-PLA复合材料的拉伸强度。结果表明:在低质量分数时,模拟值与实验值的误差相差较小。此外,还对不同质量分数的淀粉-PLA复合材料弹性模量进行了有限元预测,并探究了塑化淀粉的强度和界面性质对复合材料拉伸性能的影响。     

Temperature Change of Light Induced Explosion of explosive material

A theoretical analysis based on the adiabatic consideration of one- dimensional model for initiation of explosive materials by intense light is performed. An expression is obtained which can be used to calculate the explosion temperature.     

炸药水下爆炸冲击波参数的修正

根据有限水域中TNT、钝化RDX的测试结果,结合所采用传感器的特点．得出了一种修正冲击波参数(峰压、比冲能)的方法。结果表明,修正后的峰压与计算值接近,TNT、钝化RDX的比冲能分别占其总能量的46％、44％左右,并使测试总能量占其爆热值的95％以上。     

水下爆炸冲击波传播的近似计算

水下爆炸冲击波传播计算由能流密度一时间曲线经验表达式化简。用简单数值积分法解由拉格朗日形式流体动力学方程、Hugoniot方程和能流密度一时间关系式组成的偏微分方程组,不同距离处的冲击波峰值由单点初始数据计算。结果表明,由近似计算方法所得结果与实测数据和相似律结果一致。适当选取起算参数,在5倍装药半径以外的爆炸远场范围计算精度良好。5倍装药半径以内的爆炸近场,冲击波未充分形成,计算方法失效。计算了几种含铝炸药的冲击波传播,表明冲击波能显著影响冲击波传播特性,冲击波能有利于抑制超压衰减。     

Theoretical Prediction of Pressure and Temperature of an Aluminized High Explosive in Underwater Explosion

The blast wave propagation in underwater explosion was studied. The shock propagation in water medium was different from that in air. The blast effect in water lasted longer and offered resistance to the expansion of hot gases and release of energy. A theoretical analysis of the expansion of blast wave in water was carried out and numerical results for pressures and temperatures were obtained as functions of distance and time by analytically solving the governing equations. The initial peak pressures of blast waves, which were required for theoretical analysis were calculated using the blast wave theory. Underwater blasts with different weights (0.045, 0.5, and 1.0 kg) of the aluminized high explosive HBX‐3 were conducted to record pressure as a function of distance and time from the blast point. Theoretical results were compared with experimental data and empirical data for HBX‐3 from literature. Since the measurement of pressure and temperature at close proximity of point of detonation is difficult, theoretical modeling of underwater blast is of significant importance.     

不同起爆方式对TNT水中爆炸作用的影响

通过小型爆炸水池实验,研究了端面点起爆和中心点起爆状态下TNT装药水中爆炸能量输出结构的变化规律,并将两者进行了对比.结果表明,装药端面点起爆后,能量输出结构-冲击波压力峰值和比冲量有较大的变化,靠近起爆端方向的冲击波压力峰值和比冲量变化均较其他方位提高,端面点起爆状态比中心点起爆特定方位的冲击波压力峰值和比冲量增大约10%.得出在装药形状基本不变的条件下,改变起爆方式即可实现在水下特定方位处的爆炸能量输出结构变化.另外,聚能结构的存在,对爆炸远区冲击波比冲量的提高有益.     

TNT爆炸的数值计算及其影响因素

应用LS-DYNA有限元程序建立了模拟TNT爆炸的数值计算模型并进行了空爆冲击波超压等数值计算。通过数值计算结果与经验公式和试验数据的对比分析,验证了计算模型和参数取值的可信性。基于数值计算结果,分析了炸药材料参数、TNT药量、单元网格密度、建模方式、空气域形状和炸药形状等参数变化对爆炸冲击波超压的影响。结果表明,与试验结果相比,数值计算结果可以作为爆炸冲击波超压的下限值,而Henrych公式、Sadovskyi公式和GB6722-2003公式给出的是超压的中位和下位值;炸药材料参数的取值、单元网格密度和炸药形状对数值模拟结果的影响与比例距离相关,比例距离小于2.0时,不能忽视其影响;冲击波超压会随TNT药量的增加而小幅度增加,但建模方式和空气域形状对数值计算结果的影响可以忽略不计。     

Modeling of an Electrothermal Explosion with Account for Changes in the Thermoelectric Characteristics of a Gasless System

Combustion, Explosion, and Shock Waves - This study describes the mathematical modeling of an electrothermal explosion (ETE) of a gasless system placed in the annular layer of a conductive product....     

RDX基铝纤维炸药水下爆炸的能量分析

将RDX基铝纤维炸药和RDX基含铝炸药进行水下爆炸实验,得到两种炸药在不同位置的压力-时程曲线,经过计算得到两种炸药水下爆炸的能量,并以含铝炸药的能量为铝纤维炸药的参考能量,分析两者的差异及造成差异的原因。结果表明,与含铝炸药相比,铝纤维炸药的压力峰值与冲量降低,铝纤维炸药的比冲击波能降低11%～22%,比气泡能降低11%～15%,比爆炸能降低11%～18%。铝纤维炸药的比爆炸能占爆热的73%～82%,低于含铝粉炸药比爆炸能与爆热的比值(89%～94%)。铝纤维炸药能量未达到其参考能量的主要原因是铝纤维直径较大导致反应不充分以及熔喷法制成的铝纤维中Al2O3含量较高。     

乙醚蒸气爆炸特性数值研究

以湍流燃烧理论和CFD模拟技术为基础,对爆炸过程采用EBU-Arrhenius模型,压力与速度的耦合采用SIMPLCE算法,研究了乙醚蒸气在反应釜中气体爆炸传播过程中火焰及冲击波的传播规律和可燃液体蒸气爆炸的相关特性,验证了密闭空间中乙醚蒸气爆炸方式为爆燃,模拟过程能够较为清楚地反映可燃液体蒸气的爆炸过程,得到的爆温和爆压与理论值相近。所做工作能为可燃蒸气爆炸强度的评价提供一个良好的途径与思路,为进一步使用CFD数值模拟手段分析工业灾害中的问题提供一些帮助。