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新材料敏化的乳化炸药爆炸特性研究 总被引:1,自引:0,他引:1
通过水下爆炸与爆破切割实验,研究了新型材料敏化的乳化炸药爆炸能量输出特性。研究结果表明,材料CMLS敏化的乳化炸药相对玻璃微球敏化的乳化炸药在爆炸威力上有了很大的提高。CMLS型乳化炸药采用的是动态敏化技术,在引爆过程中,CMLS受压分解产生气体,从而引入均匀分布的小气泡,达到了敏化的目的。它保证了初始高密度装药,并且避免了由于敏化气泡破坏而造成的半爆和拒爆现象。材料CMLS分解产生的物质是含能基团,参与乳化基质的爆轰反应,因此其总输出能量会大于现有乳化炸药的输出能量。上述结果对新型乳化炸药设计具有指导意义。 相似文献
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A dense, two-phase numerical methodology is used to study the mixing layer developing behind the detonation of a heterogeneous
explosive charge, i.e., a charge comprising of a high explosive with metal particles. The filtered Navier–Stokes equations
are solved in addition to a sub-grid kinetic energy equation, along with a recently developed Eulerian–Lagrangian formulation
to handle dense flow-fields. The mixing layer resulting from the post-detonation phase of the explosion of a nitromethane
charge consisting of inert steel particles is of interest in this study. Significant mixing and turbulence effects are observed
in the mixing layer, and the rms of the radial velocity component is found to be about 25% higher than that of the azimuthal
and zenith velocity components due to the flow being primarily radial. The mean concentration profiles are self-similar in
shape at different times, based on a scaling procedure used in the past for a homogeneous explosive charge. The peak rms of
concentration profiles are 23–30% in intensity and decrease in magnitude with time. The behavior of concentration gradients
in the mixing layer is investigated, and stretching along the radial direction is observed to decrease the concentration gradients
along the azimuth and zenith directions faster than the radial direction. The mixing and turbulence effects in the mixing
layer subsequent to the detonation of the heterogeneous explosive charge are superior to that of a homogeneous explosive charge
containing the same amount of the high explosive, exemplifying the role played by the particles in perturbing the flow-field.
The non-linear growth of the mixing layer width starts early for the heterogeneous explosive charge, and the rate is reduced
during the implosion phase in comparison with the homogeneous charge. The turbulence intensities in the mixing layer for the
heterogeneous explosive charge are found to be nearly independent of the particle size for two different sizes considered
in the initial charge. Overall, this study has provided some useful insights on the mixing layer characteristics subsequent
to the detonation of heterogeneous explosives, and has also demonstrated the efficacy of the dense, multiphase formulation
for such applications. 相似文献
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A. V. Kashirskii Yu. V. Korovin L. A. Chudov 《Journal of Applied Mechanics and Technical Physics》1974,15(6):878-880
A numerical solution is obtained for the two-dimensional nonsteady problem of the motion of detonation products from a cylindrical high-explosive charge enclosed in a shell with the initiation of detonation at a central point in the end of the charge. The detonation products propagate in vacuum. The strength of the shell is not considered. A three-term equation of state is used for the detonation products. 相似文献
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A. V. Kashirskii Yu. V. Korovin V. A. Odintsov L. A. Chudov 《Journal of Applied Mechanics and Technical Physics》1974,15(2):286-287
A numerical solution is obtained to the problem of the motion of an incompressible cylindrical shell with a charge of explosive, with excitation of the detonation simultaneously along the whole axis of the charge. The strength of the shell is not taken into consideration. A three-term equation of state is adopted for the products of the detonation. In [1] a numerical solution is obtained to the problem of the one-dimensional motion of a shell with the axial detonation of a charge of explosive. 相似文献
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Meshfree particle simulation of the detonation process for high explosives in shaped charge unlined cavity configurations 总被引:8,自引:0,他引:8
The numerical simulation of the detonation of a high explosive (HE) is generally not an easy task for traditional grid based methods. Smoothed particle hydrodynamics (SPH) method, as a meshfree, Lagrangian and particle method, provides a very attractive approach in dealing with large deformations and large inhomogeneities in the extremely transient high explosive detonation and later expansion process. This paper presents the application of SPH to simulate and analyze the detonation process of high explosive in shaped charge. A three-dimensional SPH code is developed and applied to simulate the shaped charge detonation process in different scenarios. It is observed that for high explosive in a shaped charge, the detonation produced gaseous products experience strong convergence that forms an extremely high-pressure gas jet. Factors such as different charge cavity shapes and different detonation models lead to quite different behavior of the gas jet convergence and later divergence. Further analyses reveal that a critical value for the charge head length exists. Beyond this critical value, increasing the charge head length will not result in improvement on the gas jet convergence performance.Received: 11 March 2002, Accepted: 9 December 2002, Published online: 28 April 2003 相似文献
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In this paper,detonation parameters of fuel cloud,such as propylene oxide(PO),isopropyl nitrate(IPN),hexane,90 # oil and decane were measured in a self-designed and constructed vertical shock tube.Results show that the detonation pressure and velocity of PO increase to a peak value and then decrease smoothly with increasing equivalence ratio.Several nitrate sensitizers were added into PO to make fuel mixtures,and test results indicated that the additives can efficiently enhance detonation velocity and pressure of fuel cloud and one type of additive n-propyl nitrate(NPN) played the best in the improvement.The critical initiation energy that directly initiated detonation of all the test liquid fuel clouds showed a U-shape curve relationship with equivalence ratios.The optimum concentration lies on the rich-fuel side(φ > 1).The critical initiation energy is closely related to molecular structure and volatility of fuels.IPN and PO have similar critical values while that of alkanes are larger.Detonation cell sizes of PO were respectively investigated at 25 C,35 C and 50 C with smoked foil technique.The cell width shows a U-shape curve relationship with equivalence ratios at all temperatures.The minimal cell width also lies on the rich-fuel side(φ > 1).The cell width of PO vapor is slightly larger than that of PO cloud.Therefore,the detonation reaction of PO at normal temperature is controlled by gas phase reaction. 相似文献
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本文介绍了一种用光电技术同时测定爆速和爆温、爆压和爆温的方法。用光电比色技术测定炸药爆轰温度的同时,用两个爆轰面上爆轰的时间差计算爆轰波速度;或用透明介质中冲击波速度来反算炸药中的爆轰压力。方法原理可靠,技术简便。 相似文献
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Abstract. Two-dimensional numerical simulations of detonations in two-phase lean mixtures of aluminum particles and pure oxygen have
been performed. The computational procedure adopts an adaptive mesh refinement methodology in order to increase spatial resolution
in the most interesting parts of the flow field. A one-step heterogeneous reaction describes the evaporation and combustion
of aluminum. Depending on the gas-phase temperature, the combustion product is aluminum oxide or aluminum monoxide. The results
show that the heterogeneous detonations resemble gaseous single-phase ones although the scale of the phenomena is very different.
The detonation of aluminum dust evolves into the 2-headed mode of propagation with the characteristic detonation cell width equal to cm. For aluminum dust the cellular structure is much finer. The detonation initially propagates in the 11-headed mode with the characteristic
cell width equal to cm and evolves into the 8.5-headed mode with the characteristic cell size $\lambda_{\rm cell}$ equal to cm.
Received 7 May 2001 / Accepted 25 March 2002 Published online 23 January 2003
Correspondence to: K. Benkiewicz (e-mail: kbenk@cow.me.aoyama.ac.jp) 相似文献
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A two-dimensional numerical simulation has been performed to study the interaction of a gaseous detonation wave with obliquely
inclined surfaces in a variable cross-sectional chamber. The weighted essentially non-oscillatory (WENO) numerical scheme
with a relatively low resolution grid is employed. A detailed elementary chemical reaction model with 9 species and 19 elementary
reactions is used for a stoichiometric oxy-hydrogen mixture diluted with argon. In this work, we study the effect of area
expansion and contraction on the main/gross features of the detonation cellular structures in the presence of detonation reflection,
diffraction and localized explosion. The result shows that there exists a transition region as the detonation wave propagates
through the converging/diverging chamber. Within the transition region, the initial regular detonation cells become distorted
and irregular before they re-obtain their regularity. While the ultimate regular cell size and the length of the transition
region are strongly affected by the converging/diverging angle, the width/length ratio of the cells is fairly independent
of it. A localized explosion near the wall is found as the detonation wave propagates in the diverging chamber.
相似文献
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Recently, we have used scarce available data on the detonation cell size in suspensions of aluminium particles in air and oxygen to adjust the kinetic parameters of our two-phase model of detonations in these mixtures. The calculated detonation cell width was derived by means of two-dimensional (2D) unsteady simulations using an assumption of cylindrical symmetry of the flow in the tube. However, in reality, the detonation cells are three-dimensional (3D). In this work, we have applied the same detonation model which is based on the continuous mechanics of two-phase flows, for 3D numerical simulations of cellular detonation structures in aluminium particle suspensions in oxygen. Reasonable agreement on the detonation cell width was obtained with the aforementioned 2D results. The range of tube diameters where detonations in $\text{ Al/O}_2$ mixture at a given particle size and concentration would propagate in the spinning mode has been estimated (these results make a complement to our previous analysis of spinning detonations in Al/air mixtures). Coupling these results with the dependencies of detonation cell size on the mean particle diameter is of great interest for the understanding of fundamental mechanisms of detonation propagation in solid particle suspensions in gas and can help to better guide the experimental studies of detonations in aluminium suspensions. It is shown that the part of detonation wave energy used for transverse kinetic energy of both gas and particles is quite small, which explains why the propagation velocity of spinning and multi-headed detonations reasonably agrees with the ideal CJ values. 相似文献
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V. M. Gendugov 《Moscow University Mechanics Bulletin》2007,62(1):6-12
A shock wave of zero width is studied as a detonation model in the case when detonation products are in chemical equilibrium
behind this shock wave. Together with the well-known properties, some new properties of this model are found. In particular,
it is found that there exist weak and strong self-sustaining detonation waves; the latter one propagates in the Chapman-Jouguet
regime and corresponds to the point of contact of the Mikhelson line with a new-type adiabat called the extreme adiabat. 相似文献
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A. V. Kashirskii Yu. V. Korovin V. A. Odintsov L. A. Chudov 《Journal of Applied Mechanics and Technical Physics》1972,13(4):496-498
The problem of the motion of an incompressible cylindrical shell with an explosive charge is solved numerically for the propagation of a plane detonation wave from the end of the charge. The strength of the shell is not taken into account. A three-term equation of state [1] is assumed for the detonation products. A comparison is made with the one-dimensional case.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 76–79, July–August, 1972.The authors thank G. S. Roslyakov and V. M. Paskonov for assistance in the work and for helpful advice. 相似文献
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Large scale experiments on detonation initiation in gasoline-air by two different sources were carried out at stoichiometric
conditions. Unconfined clouds of volume generated by a special facility had a shape of semicylinder of 15–17 m in length and 6–8 m in radius. Both the charge
of condensed HE and the charge of stoichiometric propane-air were used to initiate detonation in the mixture. In case of initiation
by a propane-air charge the critical initiation energy was up to 7 times as large as that for HE initiation. The detonation
cell size for gasoline-air was determined as 0.04–0.05 m. It was shown, that the well-known correlation between the critical
energy of point blast initiation and the cell size failed for this system. The cell size obtained is close to one of propane-air,
but no direct transfer of detonation from one mixture to another was observed.
Received 10 March 1995 / Accepted 12 March 1995 相似文献
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This study explores the properties of spherical combustion clouds in explosions. Two cases are investigated: (1) detonation of a TNT charge and combustion of its detonation products with air, and (2) shock dispersion of aluminum powder and its combustion with air. The evolution of the blast wave and ensuing combustion cloud dynamics are studied via numerical simulations with our adaptive mesh refinement combustion code. The code solves the multi-phase conservation laws for a dilute heterogeneous continuum as formulated by Nigmatulin. Single-phase combustion (e.g., TNT with air) is modeled in the fast-chemistry limit. Two-phase combustion (e.g., Al powder with air) uses an induction time model based on Arrhenius fits to Boiko’s shock tube data, along with an ignition temperature criterion based on fits to Gurevich’s data, and an ignition probability model that accounts for multi-particle effects on cloud ignition. Equations of state are based on polynomial fits to thermodynamic calculations with the Cheetah code, assuming frozen reactants and equilibrium products. Adaptive mesh refinement is used to resolve thin reaction zones and capture the energy-bearing scales of turbulence on the computational mesh (ILES approach). Taking advantage of the symmetry of the problem, azimuthal averaging was used to extract the mean and rms fluctuations from the numerical solution, including: thermodynamic profiles, kinematic profiles, and reaction-zone profiles across the combustion cloud. Fuel consumption was limited to $\sim $ 60–70 %, due to the limited amount of air a spherical combustion cloud can entrain before the turbulent velocity field decays away. Turbulent kinetic energy spectra of the solution were found to have both rotational and dilatational components, due to compressibility effects. The dilatational component was typically about 1 % of the rotational component; both seemed to preserve their spectra as they decayed. Kinetic energy of the blast wave decayed due to the pressure field. Turbulent kinetic energy of the combustion cloud decayed due to enstrophy $\overline{\omega ^{2}} $ and dilatation $\overline{\Delta ^{2}} $ . 相似文献
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The cellular detonation structure has been recorded for hybrid hydrogen/air/aluminium mixtures on 1.0 m 0.110 m soot plates. Addition of aluminium particles to the gaseous mixture changes its detonation velocity. For very fine
particles and flakes, the detonation velocity is augmented and, in the same time, the cell width diminishes as compared with the characteristic cell size of the mixture without particles. On the contrary, for large particles, the detonation velocity decreases and the cell size
becomes larger than . It appears that the correlation law between the cell size and the detonation velocity in the hybrid mixture is similar to
the correlation between the cell size and the rate of detonation overdrive displayed for homogeneous gaseous mixtures. Moreover,
this correlation law remains valid in hybrid mixtures for detonation velocities smaller than the value D of the mixture without particles.
Received 10 May 2001 / Accepted 12 August 2002 Published online 19 December 2002
Correspondence to: B. Veyssiere (e-mail: veyssiere@lcd.ensma.fr) 相似文献
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S. B. Dorofeev A. V. Bezmelnitsin V. P. Sidorov J. G. Yankin I. D. Matsukov 《Shock Waves》1996,6(2):73-78
Large scale experiments (50 m3) have been carried out on the initiation of detonation by means of a jet of hot combustion products. The effects of hydrogen
concentration (18–30% vol.), jet orifice diameter (100–400 mm), and the mixture composition in constant volume explosion chamber
(25–50%) were investigated. Both high enough hydrogen concentration and large enough jet size are necessary for detonation
initiation. The minimum values are within the ranges of 20 to 25% vol. H2, and of 100 to 200 mm correspondingly. A minimum ratio of jet size and mixture cell width 12–13 is required for detonation
initiation. 相似文献