Relaxation of overdriven detonation waves with finite reaction rate

1972 ◽  
Vol 4 (3) ◽  
pp. 13-18
Author(s):  
S. A. Medvedev
Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4519
Author(s):  
Yakun Liu ◽  
Jianping Yin ◽  
Zhijun Wang ◽  
Xuepeng Zhang ◽  
Guangjian Bi

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.


2015 ◽  
Vol 10 (4) ◽  
pp. 77-84
Author(s):  
Evgeniy Prokhorov

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.


1999 ◽  
Author(s):  
Balu Sekar ◽  
Sampath Palaniswamy ◽  
Ryan Pfeiffer

Author(s):  
T.P. Gavrilenko ◽  
Y.A. Nikolaev ◽  
V.Y. Ulianitsky

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.


1969 ◽  
Vol 51 (3) ◽  
pp. 1250-1250 ◽  
Author(s):  
Rolf W. F. Gross ◽  
R. R. Giedt ◽  
T. A. Jacobs

Author(s):  
Kathleen B. Reuter

The reaction rate and efficiency of piperazine to 1,4-diazabicyclo-octane (DABCO) depends on the Si/Al ratio of the MFI topology catalysts. The Al was shown to be the active site, however, in the Si/Al range of 30-200 the reaction rate increases as the Si/Al ratio increases. The objective of this work was to determine the location and concentration of Al to explain this inverse relationship of Al content with reaction rate.Two silicalite catalysts in the form of 1/16 inch SiO2/Al2O3 bonded extrudates were examined: catalyst A with a Si/Al of 83; and catalyst B, the acid/phosphate Al extracted form of catalyst A, with a Si/Al of 175. Five extrudates from each catalyst were fractured in the transverse direction and particles were obtained from the fracture surfaces near the center of the extrudate diameter. Particles were also obtained from the outside surfaces of five extrudates.


Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (11) ◽  
pp. 601-607
Author(s):  
Alan Rudie ◽  
Peter Hart

The use of 50% concentration and 10% concentration hydrogen peroxide were evaluated for chemical and mechanical pulp bleach plants at storage and at point of use. Several dangerous occurrences have been documented when the supply of 50% peroxide going into the pulping process was not stopped during a process failure. Startup conditions and leaking block valves during maintenance outages have also contributed to explosions. Although hazardous events have occurred, 50% peroxide can be stored safely with proper precautions and engineering controls. For point of use in a chemical bleach plant, it is recommended to dilute the peroxide to 10% prior to application, because risk does not outweigh the benefit. For point of use in a mechanical bleach plant, it is recommended to use 50% peroxide going into a bleach liquor mixing system that includes the other chemicals used to maintain the brightening reaction rate. When 50% peroxide is used, it is critical that proper engineering controls are used to mitigate any risks.


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