球形钨合金破片终点弹道性能实验研究

实验研究了球形钨合金破片的速度衰减规律、爆轰驱动下的变形和破碎、对半无限钢靶的侵彻以及对薄钢靶的贯穿。结果表明:(1)破片长距离(120m)飞行时的衰减系数为常数,阻力系数与破片初速成线性关系;(2)在爆轰驱动下,直径为6.0和7.5mm的破片破碎率为2%～3%,而直径为8.5mm的破碎率为45%;(3)破片长距离飞行后仍有很强的穿甲能力。     

爆轰驱动变截面异形杆静态抛撒实验研究

为提高防空战斗部的毁伤后效,设计一种新型离散杆战斗部—中心起爆式变截面异形杆战斗部,并首次开展了爆轰驱动异形杆静态抛撒实验研究,获得了杆条的初速度,分析了杆条的抛撒特性、飞行姿态及其对目标钢板的侵彻效应。实验结果表明,异形杆在爆轰驱动过程中飞行姿态发生改变,达到了预期设计效果,提高了对目标的侵彻能力。     

含铝炸药爆轰驱动的非线性特征线模型

针对含铝炸药爆轰的非理想特性,提出了含铝炸药爆轰产物膨胀的局部等熵假设,建立含铝炸药爆轰驱动的非线性特征线模型,为研究含铝炸药爆轰产物的非等熵流动和膨胀做功提供了一种新的理论分析方法。设计了5、50 μm含铝炸药和含LiF炸药驱动0.5、1 mm厚金属板实验,通过激光位移干涉仪测试金属板运动的速度历程,再通过实验结果计算得到铝粉在爆轰产物中的反应度变化规律,结合含铝炸药爆轰产物的非线性特征线模型,理论计算了含铝炸药驱动金属板的速度历程。对比理论与实验结果,理论方法能够很好地描述铝粉二次反应对炸药做功能力的贡献,同时验证了含铝炸药爆轰驱动的非线性特征线模型的正确性。     

一种低附带弹药金属颗粒定向加载技术

为了实现低附带弹药金属颗粒定向可控加载,研制了采用爆轰方式驱动低附带弹药金属颗粒的发射装置,并进行了不同尺寸钨球颗粒与不同装药比的发射实验。运用高速摄影与高速红外摄影捕捉爆轰驱动过程中颗粒抛撒分布和速度,并采用CT断层扫描和三维图像重建再现了颗粒在肥皂靶中的三维空间分布。实验结果揭示了爆轰驱动下颗粒加速、减速和散落3个阶段的特征。钨球颗粒速度均值范围为689.84~889.14 m/s,最大侵彻深度为65.23~167.35 mm,颗粒加载上靶率在30%以上。发射装置中金属颗粒/装药质量比可调,能重复使用。采用肥皂靶、高速摄影、高速红外相结合的测试方法有效可行,CT图像重建用于终点弹道参数判读能提高结果分析精度。以上结果可为研究低附带弹药对生物目标的毁伤效应、致伤机理和生物损伤判定与救治提供有效可行的技术与方法。     

煤油液滴直径对两相旋转爆轰发动机流场的影响

为探究煤油液滴不同初始直径对气液两相旋转爆轰发动机流场的影响，假设初始注入的煤油液滴具有均匀直径，考虑雾化破碎、蒸发等过程，建立了非定常两相爆轰的Eulerian-Lagrangian模型，进行了液态煤油/高温空气爆轰的非预混二维数值模拟。结果表明：在初始液滴直径为1～70μm的工况范围，燃烧室内均形成了单个稳定传播的旋转爆轰波；全局当量比为1时，爆轰波前的空气区域大于液滴煤油的蒸气区域，导致波前燃料空气混合不均匀，波前均存在富油区和贫油区，两相速度差导致分离出的空气形成低温条带；当煤油液滴的初始直径较小时，波前的反应物混合过程主要受蒸发的影响，爆轰波可稳定传播；当直径减小至1μm时，煤油液滴在入口处即蒸发，旋转爆轰波表现为气相传播的特性，爆轰波结构平整；当煤油液滴的初始直径较大时，波前的反应物混合过程主要受液滴破碎的影响；对于相同的燃料质量流量，在不同初始煤油液滴直径工况下，煤油液滴最大的停留时间均占爆轰波传播时间尺度的80%以上；爆轰波前燃料预蒸发为气相的占比越高，爆轰波的传播速度越高；初始液滴直径为10～70μm的工况范围内，爆轰波的速度随初始直径的增大先升高后降低。     

初始压力和狭缝宽度对毫米量级狭缝内爆轰起爆距离的影响

为获得狭缝内爆轰起爆距离的影响因素,分别在高度为1.0 mm,宽度为10、20、30 mm的狭缝爆轰管内,对不同初始压力下(p₀=5.0~50.0 kPa)等当量比的乙烯/氧气预混气体进行了单次爆轰性能实验研究。根据烟迹法、高速摄影图片判定起爆位置,分析了初始压力和狭缝宽度对爆轰起爆距离的影响。结果表明:(1)p₀=21.0~30.0 kPa时,起爆距离随着狭缝宽度的增大而逐渐缩短;(2)p₀=35.0~42.5 kPa时,起爆距离随着狭缝宽度的增大先缩短后增大,在p₀=45.0~50.0 kPa时起爆距离随着狭缝宽度的增大基本保持不变;(3)3种狭缝宽度下,量纲一起爆距离随量纲一初始压力的变化曲线差异较大。     

战斗部轴向威力的增强

基于预制破片技术的杀伤战斗部周向破片场威力得到了很好的改善,但战斗部头部轴向破片较少,难以实现对空间域的完全封锁。为了改善杀伤战斗部轴向破片场分布,探索影响轴向预制破片飞散角和速度的影响因素,设计了一种轴向威力增强战斗部,通过改变战斗部头部形状、曲率半径并加装球形预制破片实现轴向威力增强。运用LS-DYNA软件对战斗部爆炸驱动全过程进行数值模拟,通过设置不同的起爆条件得到战斗部结构参数对轴向预制破片初速和飞散角的影响规律。仿真结果表明:预制破片的飞散角及速度与战斗部头部结构参数关系密切,采用圆弧形头部结构可显著提高预制破片的飞散速度和飞散角,使预制破片轴向封锁区域显著增大,大大增强战斗部轴向威力。     

边界条件对甲烷预混气爆轰特性的影响

通过实验研究及数字化处理研究了边界条件对CH₄预混气体爆轰特性的影响。在内径为63.5、50.8 mm圆柱形管道及长方体管道进行爆轰实验,得到胞格结构和爆轰速度曲线。烟膜数字化处理量化了预混气体的爆轰不稳定性,并计算出胞格尺寸。3种管道内测得的平均爆轰速度与CJ速度接近,边界条件的影响不明显。分析爆轰速度曲线发现,极限压力受到边界条件的影响,?50.8和?63.5 mm管道内预混气的极限压力分别为5和4.05 kPa,即随着管径增大,爆轰极限压力降低。数字化处理所得不同管道内烟膜轨迹的不规则程度无明显差别,因此可以认为不稳定性是预混气固有的性质。在相同爆轰初始压力下,管径增大,胞格数量变多,表明爆轰传播时爆轰螺旋头数增多以维持传播。     

氢气/丙烷/空气预混气体爆轰性能的实验研究

通过采用压力传感器和烟灰板两种测试设备,开展了常温常压下氢气/丙烷和空气混合气体爆轰性能的实验研究。实验过程中观察到自持爆轰波,爆轰速度比值在0.99~1之间,爆轰压力比值在0.8~1.2之间。爆轰胞格尺寸在10~50 mm范围内,建立了爆轰胞格尺寸和化学诱导长度的关系式。随着丙烷不断添加,爆轰速度减小,而爆轰压力和胞格尺寸增加。这种变化趋势起初较快,而后变缓。因为起初氢气摩尔分数较大,混合气体趋向于氢气/空气的爆轰性能;而后因丙烷摩尔质量较大,丙烷逐渐起主要作用,混合气体表现出丙烷/空气的爆轰性能。     

氢氧燃烧及爆轰驱动激波管

分析并观察了沿驱动段轴向分布多火塞燃烧驱动段的性能．提出主膜处同一管截面均匀分布三火花塞引燃的点火方法．用这种点火方法驱动产生的入射激波强度重复性较高,激波后气流速度、温度和压力的定常性亦大大改善,可满足气动试验实际要求．提出在驱动段尾端串接卸爆段来消除爆轰波反射高压,从而可使反向爆轰驱动段用来产生高焓高密度试验气流．这种反向爆轰驱动产生的入射激波重复性高,激波衰减弱．在主膜处的收缩段产生的反射波可缓解爆轰波后跟随的稀疏波的不利影响,从而使前向爆轰驱动具有实用性．在产生的入射激波强度相同条件下,前向爆轰驱动所需的爆轰驱动段可爆混合气初始压力可较反向爆轰低近一个量级．     

聚能射流侵彻页岩储层损伤裂隙形成机制

为研究药型罩对聚能射孔弹侵彻页岩储层的射孔和损伤致裂效果的影响机理，建立了射孔弹-空气-页岩三维模型，设置药型罩的锥角分别为50°、60°、70°和80°，壁厚分别为0.5、1.0和1.5 mm，材料分别为铜、钢、钛和钨。利用ANSYS/LS-DYNA软件进行数值计算，分别从射流速度与形态、页岩射孔效果及页岩孔裂隙形成规律特征等进行系统性分析。研究结果表明：在射孔弹结构中，随着药型罩锥角的减小，射流速度提高、杵体速度降低、侵彻深度增大同时开孔孔径减小。在一定范围内，适当减小药型罩的壁厚，可以提高射流速度、减小杵体质量、增大侵彻深度和开孔倾斜度。药型罩材料对射流速度、杵体结构和页岩射孔效果均有显著影响，其中钨药型罩射孔弹的侵彻深度最大但开孔孔径最小，钛药型罩射孔弹的侵彻深度最小但开孔倾斜度最大，铜比钢药型罩射孔弹的侵彻深度略大但开孔孔径略小。通过研究不同对照组的页岩孔裂隙形成规律特征发现，页岩孔裂隙发育主要发生在杵体对页岩的再扩孔阶段，减小射流初始扩孔孔径、增大杵体直径、提高杵体速度，可以促进页岩孔裂隙发育程度。     

钨球侵彻防弹衣加红松木复合靶的研究

为研究钨球对防弹衣加人体等效靶的侵彻性能,利用12.7 mm弹道枪对钨球侵彻三级软体防弹衣加25 mm厚红松靶开展了实验研究;在此基础上,利用LS-DYNA3D软件对侵彻过程及破坏机理进行了分析,并研究了钨球质量变化对弹道极限及靶板能量吸收的影响;依据量纲分析建立了钨球侵彻防弹衣加红松木复合靶的穿靶能量公式,推导了钨球的弹道极限公式。研究结果表明:0.17、0.21、0.44 g的小钨球侵彻防弹衣加红松木复合靶的弹道极限分别为742.3、692.9、570.1 m/s;侵彻过程中,防弹衣以基体开裂、纤维断裂和拉伸分层破坏为主,纤维层面内出现类似“十”字型的损伤,松木靶以剪切和冲塞剥落破坏为主;随着钨球质量的增加,弹道极限呈幂函数形式降低,靶板的能量吸收率逐渐降低;钨球穿靶能量公式及弹道极限公式的计算结果与实验结果吻合良好,可分别用于计算不同侵彻速度下的穿靶能量和不同质量钨球的弹道极限。     

Semi-theoretical analyses of the concrete plate perforated by a rigid projectile

Based on the three-stage perforation model, a semi-theoretical analysis is conducted for the ballistic performances of a rigid kinetic projectile impacting on concrete plates. By introducing the projectile resistance coefficients, dimensionless formulae are proposed for depth of penetration (DOP), perforation limit thickness, ballistic limit velocity, residual velocity and perforation ratio, with the projectile nosed geometries and projectile-target interfacial friction taken into account. Based on the proposed formula for DOP and lots of penetration tests data of normal and high strength concrete targets, a new expression is obtained for target strength parameter. By comparisons between the results of the proposed formulae and existing empirical formulae and large amount of projectile penetration or perforation tests data for monolithic and segmented concrete targets, the validations of the proposed formulae are verified. It is found that the projectile-target interfacial friction can be neglected in the predictions of characteristic ballistic parameters. The dimensionless DOP for low-to-mid speed impacts of non-flat nosed projectiles increases almost linearly with the impact factor by a coefficient of 2/(πS). The anti-perforation ability of the multilayered concrete plates is dependent on both the target plate thickness and the projectile impact velocity. The variation range of the perforation ratio is 1–3.5 for concrete targets.     

刚性钝头弹体正冲击GH4169间隔靶的消耗功分析

在380～680 m/s的弹体初速范围内，开展了直径8 mm钨球正冲击GH4169间隔靶实验，测得弹体初速、余速及靶板形貌，明显看出第1层板挠度较小,主要表现为剪切破坏，并产生了杯状挤凿块，第3层板挠度较大，主要表现为拉伸破坏。提出了间隔靶消耗功计算公式，结合剪切冲塞模型和建立的挤凿块速度模型计算了刚性钝头弹体冲击间隔靶中各层板的消耗功。结果表明，第2～3层板的单位面密度消耗功远高于相同面密度的第1层板，这与各层板的变形和失效形式密切相关。消耗功分析可用于定量描述间隔靶中各层板的抗侵彻性能。     

The influence of detonation cell size and regularity on the propagation of gaseous detonations in granular materials

This paper presents results from an experimental study of transmission of gaseous detonation waves through various granular filters. Spherical glass beads of 4 and 8 mm diameter and crushed rock of 7.5 mm volume averaged diameter were used as filter material. Varying the initial pressure of the detonating gas mixture controlled the detonation cell size. Dilution with argon was used to vary the detonation cell regularity. The complete range from almost no detonation velocity deficit to complete extinction of the combustion wave was observed. The existing correlation for gaseous detonation velocity deficit where is the critical diameter for the gaseous detonation and is the pore size, is found to be applicable for both smooth spherical particles and irregular crushed rock when considering irregular detonation structures. Soot films and pressure measurements show that as the detonation cell size is increased, reinitiation of a reanular filter until it finally no longer occurs at . Complete extinction of the combustion wave occurs at . These two limits appear to be about the same for irregular and regular detonation cell structures. For irregular structures without argon dilution, can be found for detonation wave failure, and can be found for complete extinction of the combustion wave. For argon dilution these limits are changed to and , respectively. The data are a bit scarce as a basis for proposing a new correlation for regular structures, but as a first approximation log is suggested for regular structures. The detonation or combustion wave is found to approach a constant velocity in the granular filter if not extinguished. Received 31 October 2001 / Accepted 15 July 2002 Published online 4 November 2002 Correspondence to: T. Slungaard (e-mail: slung@maskin.ntnu.no) An abridged version of this paper was presented at the 18th Int. Colloquium on the Dynamics of Explosions and Reactive Systems at Seattle, USA, from July 29 to August 3, 2001     

Experimental investigation into the detonation characteristics of hybrid RDX–ethylene–air mixtures

An experimental study is conducted to determine the detonation characteristics of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) particles dispersed in a gaseous fuel air mixture in a vertical detonation tube with an inner diameter of 200 mm and a height of 5400 mm. Experiments are performed in both ethylene–air mixtures and RDX–ethylene–air hybrid mixtures. The detonation front pressure and velocity are measured with six pressure transducers along the detonation tube. The results show that the addition of RDX assists 4.0 vol.% ethylene–air mixtures in achieving detonation. The detonation front pressure increases noticeably with dust concentration up to \(474\hbox { g/m}^{3}\) in the RDX–ethylene–air hybrid mixtures, but the velocity only increases slightly. The cellular structures of RDX–ethylene–air hybrid mixtures and ethylene–air mixtures were obtained with the use of smoked foils and exhibit irregular structures. It is found that the measured cell size has a U-shaped curve with respect to RDX concentration.     

凝聚炸药的短脉冲冲击起爆

本文介绍了利用电炮研究两种凝聚炸药（TNT/RDX=35/65和PBH-9）的短脉冲冲击起爆的实验结果。炸药样品为直径20mm,长度分别为3.0、5.0、10.0mm的圆柱及楔形药块。在所研究的实验条件下,当药柱长度大于5.0mm时,两种炸药的起爆判据可用p?=常数描述。当药柱长度小于3.0mm时,撞击飞片的阈值速度明显增加。我们还观测了飞片直径对起爆阈值速度的影响,用楔形药块观测了不同加载条件下的到爆轰时间和距离。     

Explosively driven particle fields imaged using a high speed framing camera and particle image velocimetry

A high speed framing camera and a particle image velocimetry instrument were used to determine the properties of explosively driven particle fields in early microsecond and later millisecond times. Test items were configured in a two inch long cylindrical shape with a half inch diameter core of organic explosive. The core was surrounded by a particle bed of aluminum or tungsten powder of a specific particle size distribution. Position data from the leading edge of the particle fronts for each charge was recorded with a high speed framing camera at early time and with a particle image velocimetry (PIV) instrument at later time to determine particle velocity. Using a PIV image, a velocity gradient along the length of the particle field was established by using the mean particle velocity value determined from three separate horizontal bands that transverse the particle field. The results showed slower particles at the beginning of the particle field closest to the source and faster ones at the end. Differences in particle dispersal, luminescence, and agglomeration were seen when changes in the initial particle size and material type were made. The aluminum powders showed extensive luminescence with agglomeration forming large particle structures while the tungsten powder showed little luminescence, agglomeration and no particle structures. Combining velocity data from the high speed framing camera and PIV, the average drag coefficient for each powder type was determined. The particle field velocities and drag coefficients at one meter showed good agreement with the numerical data produced from a computational fluid dynamics code that takes advantage of both Eulerian and Lagrangian solvers to track individual particles after a set post detonation time interval.     

高速碰撞下圆柱壳自由梁的穿孔特性

利用二级轻气炮加载,进行了球状2A12铝弹丸垂直撞击圆柱壳自由梁实验。并进行了弹丸速度、圆柱壳直径和壁厚等因素对穿孔直径影响的数值模拟,数值模拟结果和实验结果基本吻合。通过量纲分析和数值模拟结合,推导了穿孔直径与相关影响参数的经验关系式。研究结果表明:当圆柱壳直径和厚度不变时,高速撞击产生的穿孔直径在径向和轴向都随着弹丸速度增大而增大;当弹丸速度和圆柱壳厚度不变时,高速撞击产生的穿孔直径随着圆柱壳自由梁直径的增大而减小;当弹丸速度和圆柱壳直径不变时,穿孔直径随着圆柱壳厚度的增大而减小。