A theory for triple point spacing in overdriven detonation waves

1989 ◽  
Vol 77 (3-4) ◽  
pp. 219-228 ◽  
Author(s):  
J. Buckmaster
Keyword(s):  
Triple Point ◽  
Detonation Waves ◽  
Overdriven Detonation

scholarly journals The EFP Formation and Penetration Capability of Double-Layer Shaped Charge with Wave Shaper

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4519
Author(s):  
Yakun Liu ◽  
Jianping Yin ◽  
Zhijun Wang ◽  
Xuepeng Zhang ◽  
Guangjian Bi
Keyword(s):  
Detonation Wave ◽  
Double Layer ◽  
Detonation Velocity ◽  
Incidence Angle ◽  
Shaped Charge ◽  
Experimental Simulation ◽  
Detonation Waves ◽  
Forming Process ◽  
Large Length ◽  
Overdriven Detonation

Detonation waves will bypass a wave shaper and propagate in the form of a horn wave in shaped charge. Horn waves can reduce the incidence angle of a detonation wave on a liner surface and collide with each other at the charge axis to form overdriven detonation. Detection electronic components of small-caliber terminal sensitive projectile that are limited by space are often placed inside a wave shaper, which will cause the wave shaper to no longer be uniform and dense, and weaken the ability to adjust detonation waves. In this article, we design a double-layer shaped charge (DLSC) with a high-detonation-velocity explosive in the outer layer and low-detonation-velocity explosive in the inner layer. Numerical and experimental simulation are combined to compare and analyze the forming process and penetration performance of explosively formed projectile (EFP) in DLSC and ordinary shaped charge (OSC). The results show that, compared with OSC, DLSC can also adjust and optimize the shape of the detonation wave when the wave shaper performance is poor. DLSC can obtain long rod EFPs with a large length-diameter ratio, which greatly improves the penetration performance of EFP.

Quasi-One-Dimentional Approach To Modeling Of Propagation Of Gas Detonation In A Medium With Variable Chemical Composition

2015 ◽  
Vol 10 (4) ◽  
pp. 77-84
Author(s):  
Evgeniy Prokhorov
Keyword(s):  
Chemical Composition ◽  
Heat Removal ◽  
Detonation Waves ◽  
Detonation Products ◽  
Gas Detonation ◽  
One Dimensional ◽  
Chemical Agents ◽  
Variable Chemical ◽  
Detonation Transition ◽  
Overdriven Detonation

The quasi-one-dimensional model is presented to describe the propagation of detonation wave in a tube filled with an explosive gas mixture, the chemical composition of which varies along the tube axis. This takes into account energy losses chemical equilibrium flow of detonation products for friction and heat removal in the tube wall. Within the limits of this model, it numerically investigated the gas detonation transition through a region with the concentration gradient of chemical agents. It analyzed the possibility of excitation overdriven detonation waves as a result of this transition.

A numerical study of overdriven detonation waves

1999 ◽  
Author(s):  
Balu Sekar ◽  
Sampath Palaniswamy ◽  
Ryan Pfeiffer
Keyword(s):  
Numerical Study ◽  
Detonation Waves ◽  
Overdriven Detonation

scholarly journals Triple-point shear layers in gaseous detonation waves

2007 ◽  
Vol 586 ◽  
pp. 205-248 ◽  
Author(s):  
L. MASSA ◽  
J. M. AUSTIN ◽  
T. L. JACKSON
Keyword(s):  
Activation Energy ◽  
Triple Point ◽  
Effective Activation Energy ◽  
Shear Layers ◽  
Gaseous Detonation ◽  
Detonation Waves ◽  
Effective Activation ◽  
Helmholtz Instability ◽  
High Activation ◽  
Vortical Structures

Recent experiments have shown intriguing regions of intense luminescence or ‘hotspots’ in the vicinity of triple-point shear layers in propagating gaseous detonation waves. Localized explosions have also been observed to develop in these fronts. These features were observed in higher effective activation energy mixtures, but not in lower effective activation energy mixtures. The increased lead shock oscillation through a cell cycle in higher activation energy mixtures may result in a significantly increased disparity in the induction time on either side of the triple-point shear layer, and thus an enhanced mixing between reacted and non-reacted streams supported by Kelvin–Helmholtz instability. The relation between the shear-layer instability and the mixture effective activation energy is analysed by carrying out a spatial linear stability study for three mixtures with different activation energies and injection conditions that correspond to the experimental conditions. The role of vortical structures associated with Kelvin–Helmholtz instability in the formation of localized ignition is investigated by performing two-dimensional Navier–Stokes simulations with detailed chemical kinetics and transport. In the low activation energy mixture, large-scale vortical structures are observed to occur downstream of the induction distance; these structures do not have a noticeable effect on the reaction. In higher effective activation energy mixtures, a thin transverse ignition front develops near the interface between the two gas streams and results in a combustion structure decoupled from the entrainment region. The decoupling leads to attenuation of the instability growth rate when compared to frozen calculations, and a reduced heat release in the high vorticity region. The analysis indicates the instability plays a modest role in ignition events for high activation energy mixtures. The formation of localized explosions observed in high activation energy systems is instead linked to the impossibility of a one-dimensional reactive combustion wave supported by the injection conditions. In the absence of curvature effects and stream-tube divergence, a system of shock waves is formed which spreads the ignition to the cold gas stream.

Application of Overdriven Gaseous Detonation for Spraying

1998 ◽  
Author(s):  
T.P. Gavrilenko ◽  
Y.A. Nikolaev ◽  
V.Y. Ulianitsky
Keyword(s):  
Surface Coating ◽  
Internal Surface ◽  
Gaseous Detonation ◽  
Detonation Waves ◽  
Powder Materials ◽  
High Melting ◽  
Detonation Products ◽  
Detonation Spraying ◽  
High Melting Temperature ◽  
Overdriven Detonation

Abstract The use of overdriven detonation waves can promote coating fabrication from powder materials with high melting temperature and improve the quality coating for all materials. The detonation products flow behind overdriven detonation has kinetic and thermal energy values significantly exceeding those for self-sustaining Chapman- Jouguet's detonation, conventionally used for detonation spraying. This makes it possible to design a micro-gun and, as a consequence, the equipment for internal surface coating.

Stimulated Emission behind Overdriven Detonation Waves in F2O–H2 Mixtures

1969 ◽  
Vol 51 (3) ◽  
pp. 1250-1250 ◽  
Author(s):  
Rolf W. F. Gross ◽  
R. R. Giedt ◽  
T. A. Jacobs
Keyword(s):  
Stimulated Emission ◽  
Detonation Waves ◽  
Overdriven Detonation

The structure of the wave front in spinning detonation

1966 ◽  
Vol 26 (2) ◽  
pp. 321-336 ◽  
Author(s):  
D. H. Edwards ◽  
D. J. Parry ◽  
A. T. Jones
Keyword(s):  
Wave Front ◽  
Triple Point ◽  
Experimental Error ◽  
The Self ◽  
Detonation Waves ◽  
Mach Stem ◽  
Spinning Detonation ◽  
Schlieren Photography ◽  
The Waves ◽  
Smoked Foil

The structure and mode of propagation of spinning detonation waves in stoichiometric oxyhydrogen, at initial pressures of 20–30 mm, have been investigated. The waves were generated in a square-section tube and observations have been made by the smoked-film technique, spark schlieren photography and pressure gauges. At the front of the self-sustaining detonation waves obtained at these pressures, two Mach interactions exist, the trajectories of which are derived from the imprints made on the smoked foil. As the triple point traverses the tube section, its direction of motion is found to vary between 50° and 70° with the tube diameter. An analysis of a Mach triple point for these conditions predicts the absence of chemical reaction behind the Mach stem in the immediate neighbourhood of the triple point. Experimentally determined pressures and triple shock angles confirm, to within experimental error, the postulated theoretical configuration.

Sign in / Sign up

Export Citation Format

Share Document