Influences of negative pressure conditions on the explosion temperature field and harmful effects of emulsion explosive
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摘要: 为了探究负压条件下乳化炸药的爆轰反应机制,利用自制的可视化球形爆炸罐,通过高速摄像机、压力传感器和噪声仪分别记录乳化炸药的爆炸火焰传播过程、爆轰波压力和爆炸噪声,采用比色测温技术重构了爆炸火球的二维温度场,并深入研究了初始真空度对乳化炸药爆炸温度场、爆轰波特征参数以及爆炸噪声的影响。实验结果表明:随着初始真空度的提高,爆炸火球亮度更高,持续时间更长,形态更稳定;当真空度为0 kPa时,火球在19.35 μs时破裂,而当真空度为100 kPa时,火球在58.05 μs才开始破裂;低初始真空度对火球温度影响较小,而60 kPa以上的初始真空度会显著提高乳化炸药的爆炸温度;冲击波峰值压力和比冲量均随着初始真空度的升高而降低,但初始真空度对冲击波正压作用时间变化的影响不明显。AUTODYN数值模拟结果表明,随着真空度的提高,冲击波峰值压力降低,冲击波速度逐渐降低至与爆轰产物的膨胀速度接近。此外,初始真空度的提高有利于降低爆炸噪声,与常压相比,当罐体内真空度为100 kPa时,爆炸噪声的声压级降低了35.9 dB,降幅为29.8%。Abstract: In order to explore the mechanism of the detonation reaction of emulsion explosives under negative pressure conditions, a self-made visualized spherical explosion tank was designed, and the explosion flame propagation process, detonation wave pressure and explosion noise of emulsion explosive were measured by a high-speed camera, a pressure sensor and a noise meter, respectively. Furthermore, the two-dimensional temperature field of explosion fireball was reconstructed by using the colorimetric temperature measurement technology and the effects of the initial vacuum degree on the explosion temperature field, while the detonation wave characteristic parameters and the explosion noise of emulsion explosives were studied in depth. Combined with the simulation results of the AUTODYN software, the influences of negative pressures on the explosive pressure fields were analyzed, and the detonation mechanism of the emulsion explosive in the negative pressure environment was also discussed. The experimental results show that with the increase of the initial vacuum degree, the explosion fireball became brighter, lasted longer and had a more stable morphology; when the vacuum degree was 0 kPa, the fireball began to rupture at 19.35 μs, while the vacuum degree was 100 kPa, the fireball began to rupture at 58.05 μs; a low initial vacuum degree had little effect on the fireball temperature, while the initial vacuum degree above 60 kPa would significantly increase the explosion temperature of emulsion explosives. The peak pressure and specific impulse of shock wave decreased with the increase of initial vacuum degree, while the effect of initial vacuum degree on the positive pressure action time of shock wave was not obvious. AUTODYN numerical simulation results show that the peak pressure of the shock wave decreases with the increase of the vacuum degree, the shock wave velocity gradually decreases, being closer to the expansion velocity of the detonation product. In addition, the increase of the initial vacuum degree was beneficial for the reduction of the explosion noise, compared with atmospheric pressure, when the vacuum degree in the tank was 100 kPa, the sound pressure level of explosion noise was reduced by 35.9 dB, with a reduction of 29.8%.
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Key words:
- vacuum explosion /
- emulsion explosive /
- colorimetric pyrometer /
- shock wave parameters /
- explosion noise
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表 1 乳化炸药试样质量
Table 1. Mass of emulsion explosive samples
真空度/kPa 质量/g 样品1 样品2 样品3 0 20.01 19.99 20.03 20 19.97 20.04 20.03 40 19.98 20.01 20.00 60 20.00 19.96 20.01 80 20.02 20.04 20.03 100 20.04 19.98 19.99 表 2 爆炸火球在不同真空度下的持续时间
Table 2. Duration of explosive fireballs under different vacuum degrees
真空度/kPa 火球持续时间/μs 0 45.15 20 51.60 40 64.50 60 70.95 80 77.40 100 90.30 表 3 不同真空度下乳化炸药爆炸的冲击波参数
Table 3. Shock wave parameters for explosion of emulsion explosive under different vacuum degrees
真空度/kPa 峰值压力/kPa 正压作用时间/μs 正冲量/(Pa·s) 0 64.58 542 13.18 20 61.44 541 11.98 40 57.19 543 10.92 60 53.04 532 10.43 80 44.06 526 9.11 100 25.76 514 4.17 表 4 不同真空度下的空气密度
Table 4. Air density under different vacuum degrees
真空度/kPa 空气密度/(kg·m−3) 0 1.225 20 0.980 40 0.735 60 0.490 80 0.245 100 0.0123 -
[1] CHENG Y F, MA H H, LIU R, et al. Explosion power and pressure desensitization resisting property of emulsion explosives sensitized by MgH2 [J]. Journal of Energetic Materials, 2014, 32(3): 207–218. DOI: 10.1080/07370652.2013.818078. [2] 程扬帆, 汪泉, 龚悦, 等. MgH2型复合敏化储氢乳化炸药的制备及其爆轰性能 [J]. 化工学报, 2017, 68(4): 1734–1739. DOI: 10.11949/j.issn.0438-1157.20161341.CHENG Y F, WANG Q, GONG Y, et al. Preparation and detonation properties of MgH2 type of composite sensitized emulsion explosives [J]. CIESC Journal, 2017, 68(4): 1734–1739. DOI: 10.11949/j.issn.0438-1157.20161341. [3] 李志敏, 汪旭光, 汪泉, 等. 负压环境对炸药爆炸冲击波影响的实验研究 [J]. 火炸药学报, 2021, 44(1): 35–40. DOI: 10.14077/j.issn.1007-7812-202007025.LI Z M, WANG X G, WANG Q, et al. Experimental study on the effect of negative pressure environment on explosion shock wave [J]. Chinese Journal of Explosives and Propellants, 2021, 44(1): 35–40. DOI: 10.14077/j.issn.1007-7812-202007025. [4] 李孝臣, 汪泉, 谢守冬, 等. 负压条件下球形爆炸容器内乳化炸药冲击波参数研究 [J]. 火炸药学报, 2023, 46(3): 252–259. DOI: 10.14077/j.issn.1007-7812.202207001.LI X C, WANG Q, XIE S D, et al. Study of shock wave parameters of emulsified explosives in spherical explosive containers under negative-pressure conditions [J]. Chinese Journal of Explosives & Propellants, 2023, 46(3): 252–259. DOI: 10.14077/j.issn.1007-7812.202207001. [5] SILNIKOV M V, CHERNYSHOV M V, MIKHAYLIN A I. Blast wave parameters at diminished ambient pressure [J]. Acta Astronautica, 2015, 109: 235–240. DOI: 10.1016/j.actaastro.2014.12.007. [6] JIANG F, WANG X F, HUANG Y F, et al. Effect of particle gradation of aluminum on the explosion field pressure and temperature of RDX-based explosives in vacuum and air atmosphere [J]. Defence Technology, 2019, 15(6): 844–852. DOI: 10.1016/j.dt.2019.06.007. [7] WANG F Q, WANG Q, WANG Y J, et al. Propagation rules of shock waves in confined space under different initial pressure environments [J]. Scientific Reports, 2022, 12(1): 14352. DOI: 10.1038/s41598-022-18567-0. [8] XI P, SUN S Y, SHANG Y, et al. Internal explosion performance of RDX@nano-B composite explosives [J]. Nanomaterials, 2023, 13(3): 412. DOI: 10.3390/nano13030412. [9] 汪泉, 林朝键, 李志敏, 等. 负压条件下爆炸罐内爆炸引起筒体振动及噪声特性 [J]. 振动与冲击, 2021, 40(6): 135–139, 200. DOI: 10.13465/j.cnki.jvs.2021.06.018.WANG Q, LIN C J, LI Z M, et al. Vibration and noise characteristics of a cylinder body caused by the explosion in an explosion tank under negative pressure [J]. Journal of Vibration and Shock, 2021, 40(6): 135–139, 200. DOI: 10.13465/j.cnki.jvs.2021.06.018. [10] VELDMAN R L, NANSTEEL M W, CHEN C C T, et al. The effect of ambient pressure on blast reflected impulse and overpressure [J]. Experimental Techniques, 2017, 41(3): 227–236. DOI: 10.1007/s40799-017-0171-8. [11] 李科斌, 李晓杰, 闫鸿浩, 等. 不同真空度下空中爆炸近场特性的数值模拟研究 [J]. 振动与冲击, 2018, 37(17): 270–276. DOI: 10.13465/j.cnki.jvs.2018.17.038.LI K B, LI X J, YAN H H, et al. Numerical simulation for near-field characteristics of air explosion under different degrees of vacuum [J]. Journal of Vibration and Shock, 2018, 37(17): 270–276. DOI: 10.13465/j.cnki.jvs.2018.17.038. [12] 张启威, 程扬帆, 夏煜, 等. 比色测温技术在瞬态爆炸温度场测量中的应用研究 [J]. 爆炸与冲击, 2022, 42(11): 114101. DOI: 10.11883/bzycj-2021-0477.ZHANG Q W, CHENG Y F, XIA Y, et al. Application of colorimetric pyrometer in the measurement of transient explosion temperature [J]. Explosion and Shock Waves, 2022, 42(11): 114101. DOI: 10.11883/bzycj-2021-0477. [13] YAO Y L, CHENG Y F, ZHANG Q W, et al. Explosion temperature mapping of emulsion explosives containing TiH2 powders with the two-color pyrometer technique [J]. Defence Technology, 2022, 18(10): 1834–1841. DOI: 10.1016/j.dt.2021.09.020. [14] WANG Z H, CHENG Y F, MOGI T, et al. Flame structures and particle-combustion mechanisms in nano and micron titanium dust explosions [J]. Journal of Loss Prevention in the Process Industries, 2022, 80: 104876. DOI: 10.1016/j.jlp.2022.104876. [15] HU F F, CHENG Y F, ZHANG B B, et al. Flame propagation and temperature distribution characteristics of magnesium dust clouds in an open space [J]. Powder Technology, 2022, 404: 117513. DOI: 10.1016/j.powtec.2022.117513. [16] CHENG Y F, YAO Y L, WANG Z H, et al. An improved two-colour pyrometer based method for measuring dynamic temperature mapping of hydrogen-air combustion [J]. International Journal of Hydrogen Energy, 2021, 46(69): 34463–34468. DOI: 10.1016/j.ijhydene.2021.07.224. [17] 张广华, 李彪彪, 沈飞, 等. 真空条件下炸药爆炸特性试验研究 [J]. 火炸药学报, 2020, 43(3): 308–313. DOI: 10.14077/j.issn.1007-7812.201903005.ZHANG G H, LI B B, SHEN F, et al. Experimental research on the explosion performance of explosives under vacuum conditions [J]. Chinese Journal of Explosives and Propellants, 2020, 43(3): 308–313. DOI: 10.14077/j.issn.1007-7812.201903005. [18] 汪泉, 陆军伟, 李志敏, 等. 负压条件下柱形爆炸罐内爆炸波传播规律 [J]. 兵工学报, 2021, 42(6): 1250–1256. DOI: 10.3969/j.issn.1000-1093.2021.06.015.WANG Q, LU J W, LI Z M, et al. Propagation law of explosion wave in columnar explosion tank under vacuum conditions [J]. Acta Armamentarii, 2021, 42(6): 1250–1256. DOI: 10.3969/j.issn.1000-1093.2021.06.015. [19] 辛春亮, 王俊林, 余道建, 等. TNT空中爆炸冲击波的工程和数值计算 [J]. 导弹与航天运载技术, 2018(3): 98–102. DOI: 10.7654/j.issn.1004-7182.20180319.XIN C L, WANG J L, YU D J, et al. Empirical formula and numerical simulation of TNT explosion shock wave in free air [J]. Missiles and Space Vehicles, 2018(3): 98–102. DOI: 10.7654/j.issn.1004-7182.20180319. [20] 李瑞, 李孝臣, 汪泉, 等. 低温和低压环境下炸药爆炸冲击波的传播特性 [J]. 爆炸与冲击, 2023, 43(2): 022301. DOI: 10.11883/bzycj-2022-0188.LI R, LI X C, WANG Q, et al. Propagation characteristics of blast wave in diminished ambient temperature and pressure environments [J]. Explosion and Shock Waves, 2023, 43(2): 022301. DOI: 10.11883/bzycj-2022-0188. [21] 陆军伟, 汪泉, 李志敏, 等. 环境压力对自由场冲击波传播影响的数值模拟 [J]. 工程爆破, 2021, 27(2): 51–57. DOI: 10.19931/j.EB.20200164.LU J W, WANG Q, LI Z M, et al. Numerical simulation of the influence of environmental pressure on free field shock wave propagation [J]. Engineering Blasting, 2021, 27(2): 51–57. DOI: 10.19931/j.EB.20200164. [22] 韩崇刚, 郭成更, 王娜峰. 基于AUTODYN的乳化炸药水下爆炸能量分布的数值研究 [J]. 工程爆破, 2018, 24(1): 27–31, 77. DOI: 10.3969/j.issn.1006-7051.2018.01.005.HAN C G, GUO C G, WANG N F. Numerical studies on energy distribution of emulsion explosives using AUTODYN [J]. Engineering Blasting, 2018, 24(1): 27–31, 77. DOI: 10.3969/j.issn.1006-7051.2018.01.005.