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瓦斯爆炸诱导沉积煤尘爆炸的数值模拟 总被引:2,自引:0,他引:2
建立了描述瓦斯爆炸卷扬沉积煤尘参与爆炸的物理和数学模型,借助流场模拟平台,对瓦斯爆炸
卷扬沉积煤尘参与爆炸的过程进行了数值模拟;并把模拟值与实验值进行了对比;对爆炸过程中的速度场和
温度场进行了深入的分析。通过比较分析爆炸压力、速度场以及温度场,认为模拟结果清楚地展现了沉积煤
尘的扬起和爆炸过程,达到了瓦斯爆炸诱导沉积煤尘爆炸数值模拟的要求。 相似文献
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从爆炸力学的观点分析世贸大厦塔楼倒塌的过程 总被引:4,自引:0,他引:4
运用气体爆炸以及爆炸力学的基本理论对飞机撞击世贸大厦塔楼以及塔楼随后的倒塌过程进行了初步分析研究,并对世贸大厦北楼先撞而后倒,南楼后撞而先倒的原因也进行了分析。 相似文献
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爆炸容器内壁所受爆炸载荷的确定是容器动态响应特征研究、容器结构设计及安全评估的基础。对自行研制的组合式圆柱形爆炸容器开展了系列内爆加载试验,测量了容器内壁几个典型位置所受爆炸载荷,并利用ANSYS/LS-DYNA软件对容器内爆载荷的形成和传播全过程进行了数值模拟。通过对试验结果进行分析,获得了容器内壁所受爆炸载荷的特征及其分布规律,并拟合出容器圆柱形壳体部分所受载荷首脉冲的峰值压力、正压作用时间和比冲量经验计算公式、容器内部准静态压力经验计算公式。通过对数值模拟结果进行分析,阐明了容器内壁所受爆炸载荷特征和分布规律的形成机理。研究结果表明,椭球端盖内壁产生的马赫反射波在端盖极点汇聚,使得极点所受载荷峰值压力及单次脉冲比冲量峰值总是所有测点中最大的,峰值压力最高可达圆柱壳所受最大压力的2.79倍,应予以足够重视。 相似文献
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爆炸容器内壁所受爆炸载荷的确定是容器动态响应特征研究、容器结构设计及安全评估的基础。对自行研制的组合式圆柱形爆炸容器开展了系列内爆加载试验,测量了容器内壁几个典型位置所受爆炸载荷,并利用ANSYS/LS-DYNA软件对容器内爆载荷的形成和传播全过程进行了数值模拟。通过对试验结果进行分析,获得了容器内壁所受爆炸载荷的特征及其分布规律,并拟合出容器圆柱形壳体部分所受载荷首脉冲的峰值压力、正压作用时间和比冲量经验计算公式、容器内部准静态压力经验计算公式。通过对数值模拟结果进行分析,阐明了容器内壁所受爆炸载荷特征和分布规律的形成机理。研究结果表明,椭球端盖内壁产生的马赫反射波在端盖极点汇聚,使得极点所受载荷峰值压力及单次脉冲比冲量峰值总是所有测点中最大的,峰值压力最高可达圆柱壳所受最大压力的2.79倍,应予以足够重视。 相似文献
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本文是利用炸药爆炸所产生的高压气体为加载手段,导出了在低速的情况下,弹射器的弹丸质量、弹丸的速度、与药量以及爆炸腔的体积、加速段长度之间的近似关系,根据这一关系设计了爆炸弹射器初加载装置。并用实验结果与近似计算做了比较。 相似文献
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密闭空间煤粉的爆炸特性 总被引:4,自引:0,他引:4
利用ISO6184/1和IEC推荐的20L球型爆炸测试装置,对4种规格的煤粉进行了系统的粉尘爆炸实验,探讨了煤粉的爆炸规律。得到了样品的爆炸下限浓度、最大爆炸压力,最大爆炸压力上升速率变化规律;分析了浓度、粒径、点火能量对煤粉爆炸猛烈度的影响。结果表明,粒径越小的煤粉,爆炸下限越小,而且在指定浓度下爆炸越猛烈。随着浓度的增大,最大爆炸压力和上升速率先增后减。样品3,峰值爆炸压力对应的浓度为400~1000g/m3,爆炸压力最大值为0.54MPa;点火头能量的增大在一定程度上促使反应更充分,从而爆炸强度更强。由于煤粉组成的特点,实验数据一定程度上说明了爆炸过程中气相燃烧的重要作用。 更多还原 相似文献
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The problem of peripheral explosion in a star initially at equilibrium is solved for an exponential density distribution.
Qualitatively new flow modes, such as recurrent ejection of the star shell and partial scatter of its matter in interstellar
space, are obtained. The critical energies corresponding to various flow modes are determined. Calculations conducted over
a wide range of the determining parameters allow certain conclusions to be drawn concerning the possibility of explaining
the phenomena occurring in the interior of pulsing and variable stars.
The problem of dynamic explosion of star equilibrium, followed by the formation of a detonation wave travelling through a
gravitating gas at rest, is also considered. It is shown that various solutions involving detonation may be constructed by
choosing the adiabatic exponent and the exponent of the power density distribution.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 157–163, May–June, 1998. 相似文献
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B. V. Putyatin 《Fluid Dynamics》1980,15(3):383-389
A study is made of the initial stage of a point explosion in a radiating gray gas whose absorption coefficient is approximated by the dependenceK=x()e
–n
,where is the density and e is the internal energy of the gas. It is shown that for n > —1/3 the initial stage of the process differs significantly from the solution of the problem in not only the classical adiabatic case [1, 2] but also in the case of a medium with nonlinear thermal conductivity [2–4]. The supply of energy to the medium at a point leads to instantaneous heating of the complete medium. The form of this heating is found analytically. The method of matched asymptotic expansions is used to investigate the behavior of the solution in the neighborhood of the center. It is found that for definite conditions at the center of the perturbed region there are formed a shock wave and a region of reverse flow of the gas.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 75–82, May–June, 1980.I should like to thank V. P. Korobeinikov for interest in the work and a helpful discussion of it. 相似文献
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Assume that a planar, cylindrical, or spherical point explosion takes place in a combustible mixture of gases. As a result of the explosion a strong shock wave develops and triggers chemical reactions with the release of heat. The solution of the problem for the case in which the thickness of the heat release zone is neglected (the infinitely thin detonation wave model) was obtained in [1–3].It was emphasized in [4] that these solutions can be considered only as asymptotic solutions for time and distance scales which are large in comparison with the scales which are characteristic for the chemical reactions, and under the assumption that as the overdriven detonation wave which is formed in the explosion is weakened by the rarefaction waves it does not degenerate into an ordinary compression shock. Here the question remains open of the possibility of obtaining such asymptotic solutions with account for finite chemical-reaction rates.In conclusion the authors wish to thank E. Bishimov for carrying out most of the computations for this study. 相似文献
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I. M. Lyuboshits 《Fluid Dynamics》1968,3(1):105-108
We consider an underwater gas explosion in a cylindrical tank which is open at the bottom. The pressure field in the water is a toroidal compression wave with gradually increasing pressure behind the wave front. In the linear approximation the pressure shock occurs only under the cylinder with the gas. Filling of the lower portion of the cylinder with water alters the compression wave profile.The results obtained may be used in marine seismological prospecting for developing sources for exciting elastic vibrations which are not hazardous to the fish population, in explosive cleaning of filters in water wells, etc. 相似文献