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铝粉含量和粒度对CL-20含铝炸药水中爆炸反应特性的影响 总被引:1,自引:0,他引:1
为了研究CL-20基含铝炸药的爆炸反应机理,利用水中爆炸实验,测量了不同铝粉含量和粒度的CL-20炸药水中爆炸的冲击波参数、二次压力波参数,计算了冲击波能和气泡能。结果表明,水中爆炸的冲击波能和气泡能表征了爆轰和二次反应两个阶段的炸药爆炸能量分配,CL-20炸药中的铝粉主要在二次反应阶段发生反应,只有少部分的铝粉参与了早期的爆轰反应。气泡脉动形成的二次压力波能描述铝粉含量和粒度对二次反应过程的影响,铝粉含量对炸药的二次反应有显著的影响;铝粉粒度对炸药的水下爆炸的初始冲击波参数、冲击波能和气泡能的影响很小,对铝粉与爆轰产物的二次反应速率影响较大。 相似文献
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采用锰铜压力计和PVDF压力计的多计测试技术以及高速扫描实验技术,对含铝炸药水中爆炸近场冲击波进行了测量。压力计的测试结果表明,采用一个锰铜压力计和多个PVDF计同时测量炸药水中爆炸近场冲击波压力是可行的,但不能同时采用多个锰铜压力计进行测量。高速扫描相机记录了冲击波自出炸药端面到约60mm距离内冲击波传播轨迹,经过数字化分析计算得到了冲击波峰值压力随距离变化曲线。分析表明,压力计和高速扫描相机的测试结果符合较好,说明测试技术和分析方法是可行的。将压力计和高速扫描相机结合起来,有助于更好地研究含铝炸药水中爆炸近场冲击波特性。 相似文献
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CL-20基炸药水中爆炸气泡脉动实验研究 总被引:1,自引:0,他引:1
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。 相似文献
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提出通过水中实验确定炸药的水中爆轰产物JWL状态方程参数的方法;选择PBX-01高能炸药进行水中实验,利用ANSYS/LS-DYNA程序建立炸药的水中实验模型,将实验结果与数值计算结果进行对比,确定PBX-01炸药水中爆轰产物的JWL状态方程参数。研究结果显示,圆筒实验确定的JWL参数在反映炸药水中爆轰产物的膨胀状态时有所不足,水中实验确定的JWL状态方程参数能够更准确地描述PBX-01炸药水中爆轰产物的膨胀过程,因此对水中爆炸的研究需要通过水中爆炸实验建一套状态方程参数。 相似文献
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如何准确界定“近距离爆炸(close-in explosion)”一直是防护工程研究领域的热点。本文中基于已被充分验证的精细化有限元模型,研究了TNT球形装药自由场爆炸冲击波传播与爆轰产物高速膨胀共同作用的特点和规律,发现在比例爆距小于0.80 m/kg1/3的范围内,爆轰产物对刚性壁面的爆炸荷载影响显著,提出球形装药近距离爆炸的比例爆距界定标准为0.30~0.80 m/kg1/3。研究发现,在近距离爆炸下,爆炸波在入射角为0°~5°范围内的刚性壁面反射荷载峰值会出现急剧下降的现象,这是由爆轰产物喷射的不均匀性和随机性导致的;近距离爆炸下,刚性壁面反射超压出现了两个峰值的现象,这是由冲击波和爆轰产物分别与刚性壁面相互作用导致的。提出了近距离爆炸情况下两个荷载峰值的计算公式,以及适合工程结构响应计算的简化荷载模型;揭示了近距离爆炸下刚性壁面反射超压的分布规律。 相似文献
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Three-dimensional numerical simulation of detonations in both a circular tube and a coaxial tube are simulated to reveal characteristics
of single spinning and two-headed detonations. The numerical results show a feature of a single spinning detonation which
was discovered in 1926. Transverse detonations are observed in both tubes, however, the single spinning mode maintains the
complex Mach reflection whereas the two-headed mode develops periodically from the single Mach reflection to the complex one.
The calculated cell aspect ratio for the two-headed mode changes from 1.09 to 1.34 as the radius of axial insert increases
from r
1/R = 0.1 to 0.9. The calculated cell aspect ratio for r
1/R = 0.1 is close to the experimental results without an axial insert. The formation of an unreacted gas pocket behind the detonation
front was not observed in the single spinning mode; however, the two-headed mode has unreacted gas pocket behind the front
near the axial insert.
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An analysis of theoretical models and experimental investigations of the detonability of unconfined detonation in uniform
gaseous mixtures shows a disparity in results. The present study is limited to propane, acetylene and methane diluted with
oxygen or air in variable proportions and initial pressures at ambient temperature conditions. Because of the disparity in
results, a simple and general formulation of critical initiation energy for gaseous detonations has been investigated. The
problem has been formulated using the conservation equation of total energy enclosed by the shock. From this, a simple form
for the critical energy has been deduced. This approach leads to a good simulation in uniform mixtures, regardless of initiation
conditions. Some applications are presented in this paper.
A new experimental study on the detonability of methane/oxygen mixtures diluted with propane and/or nitrogen is reported.
The gaseous mixtures are confined in a cylindrical vessel. The initial conditions are various equivalence ratio and pressure
under room temperature. In the case of methane/oxygen mixtures, the predetonation radius varies directly with the cell width.
The constant ratio is in the order of 18, slightly different from the classical relation R
c= 20λ. For propane the slope variation of the critical energy versus initial pressure depends on the dilution.
We have compared the critical energy obtained by several authors with the theoretical values. Fuel ratio and initial pressure
are the chosen parameters. These comparisons show that the formulation allows for the prediction of the critical energy of
detonation of uniform mixtures with a good estimation range. The correlation between the different geometries has been deduced
and a test has been conducted as well in the case of stoichiometric methane/oxygen and acetylene/oxygen mixtures versus initial
pressure for a cylindrical detonation.
Received 9 January 1996 / Accepted 24 January 1997 相似文献
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Experimental study on spherically imploding detonation waves 总被引:1,自引:0,他引:1
Spherically imploding detonation waves propagating in a stoichiometric propane-oxygen mixture in a convergent hemispherical space having an innerdiameter of 800 mm were experimentally investigated with an intention to clarify the reason for the anomalous increase of the pressure and temperature behind the imploding detonation waves observed in a smaller vessel having an inner-diameter of 360 mm. The relations between the radial distance of the detonation front, the peak pressure, spectroscopic temperature at the imploding detonation front and those behind the shock waves reflected from the implosion focus show almost the same tendencies as in the smaller convergent space. The pressure as well as the temperature at the imploding detonation front increases, with the propagation of the implosion, more rapidly than theoretically estimated. The reason for it is attributed to the double imploding detonation waves.This article was processed using Springer-Verlag TEX Shock Waves macro package 1990. 相似文献
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凝聚炸药非理想爆轰的数值模拟 总被引:2,自引:0,他引:2
本文对凝聚炸药非理想爆轰的数值模拟进行了系统介绍。对敏感、钝感炸药的理想与非理想爆轰的数值模拟方法、宏观反应速率方法及近年发展起来的DSD(DetonationShockDyntimics)方法和波阵面追踪法,以及对这些方法的适应能力、存在的主要问题进行了分析与讨论。 相似文献
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大型水平爆轰管中悬浮铝粉爆炸过程的实验研究 总被引:1,自引:0,他引:1
铝粉的燃烧与爆轰性能是粉尘爆炸领域研究的热点.利用长29.6m,内径199mm,配有40套喷粉扬尘系统的水平爆轰管,在40J电火花点火条件下,实现了悬浮铝粉-空气混和物火焰加速、爆燃、爆轰及其转捩过程,测得了爆炸波传播过程中的压力信号,并且观察到了爆轰波的稳定传播现象.实验结果表明,当铝粉浓度为300 g/m3时,在距离点火端10.15m(长径比L/D=51)处发生了DDT,测得的爆轰波传播过程中管内的最大爆速为1840m/s,最大峰值超压为10.5MPa.铝粉尘爆炸波在爆轰管内的传播过程可分为爆燃段、爆燃转爆轰(DDT)、爆轰增强以及稳态爆轰四个阶段. 相似文献
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建立了长2 800 mm、内径为50 mm的圆管内爆轰波传播实验装置,采用光电二极管探测火焰锋面以获得爆轰波的传播速度,采用烟迹法记录爆轰波的胞格结构。通过在管道不同位置设置阻塞率为1的聚丙烯薄膜,研究不同初始压力下不同氩气稀释浓度的C2H2+2.5O2+nAr预混气体爆轰波在通过全阻塞障碍物前后传播速度及胞格结构的变化。结果表明,气相爆轰波在达到稳态爆轰后,在通过全阻塞薄膜障碍物的过程中会产生2种不同的传播形式:速度亏损和爆轰失效。气相爆轰波穿过不同区域的传播过程可以分为3个阶段:稳态传播阶段、速度亏损阶段或爆轰失效阶段、过驱爆轰阶段。 相似文献
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Doppler interferometry study of unstable detonations 总被引:2,自引:0,他引:2
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气相爆轰物理的若干研究进展 总被引:1,自引:0,他引:1
爆轰现象的研究已经有一百多年的历史了,爆轰物理的研究取得了许多重要进展.本文从爆轰波的经典理论、胞格爆轰波的多波结构、气相爆轰波形成机理、气相爆轰波传播机制等方面综述了相关的若干研究进展,评述了这些进展的科学性与局限性,并探讨了将来可能的研究方向.这些研究进展主要包括:CJ(Chapman-Jouguet)理论和ZND(Zel'dovich,von Neumann,D?ring)模型、爆轰波多波结构、爆轰胞格特征、直接起爆和爆燃转爆轰过程、热点起爆机制、爆轰波稳定性、扰动爆轰波的传播等.爆轰波是以超声速传播的自持燃烧现象,涉及了激波相互作用、燃烧化学反应、湍流扩散和流动不稳定性等复杂的气动物理过程,相关研究具有重要的学科理论意义.另外,爆轰燃烧具有高效的热化学能释放特点,在先进的热力推进技术方面有着重要的应用背景,因此相关研究也具有重要的工程应用价值. 相似文献