A spherical explosion wave in soils

1976 ◽  
Vol 12 (5) ◽  
pp. 718-720 ◽  
Author(s):  
R. G. Yakupov
2012 ◽  
Vol 57 (3) ◽  
pp. 601-618 ◽  
Author(s):  
Vasyl Moisyshyn ◽  
Vasyl Yacyshyn ◽  
Oleg Vytyaz

Abstract Studied here are the results of the asymmetric problem solution of the thick walled circular cylinder elasticity using the spatial characteristics technique. The practical implementation of the solution of the problem is based on the calculation of the stress-caused deformation state of the stuck drilling string zone affected by the explosion wave action upon the inner wall of the pipe. Suggested here is the technique for determining axual σz and circular σθ stress on the drill pipe wall as well as the radial displacements ur of the stuck drill pipe outer surface under the action of the explosion shock wave. The above technique enables to make a sound selection of the cylindrical explosive charge weight in order to avoid the residual strain during the drilling string shaping off and uncoupling the threaded joints or to prevent them from exceeding the admissible level.


2016 ◽  
Vol 11 (1) ◽  
pp. 60-65 ◽  
Author(s):  
R.Kh. Bolotnova ◽  
E.F. Gainullina

The spherical explosion propagation process in aqueous foam with the initial water volume content α10=0.0083 corresponding to the experimental conditions is analyzed numerically. The solution method is based on the one-dimensional two-temperature spherically symmetric model for two-phase gas-liquid mixture. The numerical simulation is built by the shock capturing method and movable Lagrangian grids. The amplitude and the width of the initial pressure pulse are found from the amount of experimental explosive energy. The numerical modeling results are compared to the real experiment. It’s shown, that the foam compression in the shock wave leads to the significant decrease in velocity and in amplitude of the shock wave.


In previous papers of this series it was shown that the secondary formation of nitric oxide in CO-O 2 -N 2 explosions, when oxygen is present in excess of that required to burn all the carbonic oxide, rapidly increases with the density of the medium, the optimum composition of the medium for the purpose being 2CO + 3O 2 + 2N 2 . The former experiments were carried out, in bombs Nos. 2 and 3, the 7·5 cm. diameter spherical explosion chambers of which were each of 240 c.c. capacity with a surface/volume ratio 0·78, under conditions permitting of no acceleration in the normal rate of cooling down of the hot products from the maximum explosion temperature.


2005 ◽  
Vol 192 ◽  
pp. 309-314
Author(s):  
Hideki Madokoro ◽  
Tetsuya Shimizu ◽  
Yuko Motizuki

SummaryWe examine effects of small-scale fluctuations with angle in the neutrino radiation in core-collapse supernova explosions. As the mode number of fluctuations increases, the results approach those of spherical explosion. We conclude that global anisotropy of the neutrino radiation is the most effective mechanism of increasing the explosion energy when the total neutrino luminosity is given.


2016 ◽  
Vol 23 (s1) ◽  
pp. 131-137 ◽  
Author(s):  
Baiwei Lei ◽  
Bing Wu ◽  
Yatong Zhao ◽  
Muhammad Aqeel Ashraf

Abstract In coal mine fire rescues, if the abnormal increase of gas concentration occurs, it is the primary thing to analyze the reasons and identify sources of the abnormal forming, which is also the basis of judge the combustion state of fire area and formulate proper fire reliefs. Nowadays, related researches have recognized the methane explosion as the source of high concentration of H2 formation, but there are few studies about the conditions and reaction mechanism of gas explosion generating high concentration of H2.Therefore, this paper uses the chemical kinetic calculation software, ChemKin, and the 20L spherical explosion experimental device to simulate the generating process and formation conditions of H2 in gas explosion. The experimental results show that: the decomposition of water vapor is the main base element reaction (R84) which leads to the generation of H2.The free radical H is the key factor to influence the formation of H2 generated from gas explosion. With the gradual increase of gas explosion concentration, the explosive reaction becomes more incomplete, and then the generating quantity of H2 increases gradually. Experimental results of 20L spherical explosion are consistent with the change trend about simulation results, which verifies the accuracy of simulation analysis. The results of explosion experiments show that when gas concentration is higher than 9%, the incomplete reaction of methane explosion increases which leads to the gradual increase of H2 formation.


2011 ◽  
Vol 101-102 ◽  
pp. 365-368
Author(s):  
Zhan Fei Zhu ◽  
Quan Shi ◽  
Guang Yan Wang ◽  
Hang Lu

In order to study the influence of charge weight and blast position on damage effect of EPW (Earth Penetrating Weapon), theoretic analysis was combined with experiment data, the model of volume of funnel pit formed by blast was set up based on supposing that the warhead was instantaneous spherical explosion and the fragments’ destructive effect could be neglected, then the model was discussed in detail. The results are helpful to the launch and control of the EPW and have reference value for the building of contravallation and underground blindage.


The measurement of the pressure produced in the “explosion-wave” in gaseous mixtures is difficult because of the rapidity of movement of the wave and the short time for which the pressure over any given area lasts. In 1894 Dixon and Cain pointed out that the pressures obtained by firing a mixture in a closed vessel did not correspond to pressures in the wave front. Following a suggestion of Mallard and Le Chatelier, they used a method in which glass tubes of known strength were fractured by the explosion-wave, it being assumed that “if a pressure is produced in a glass tube greater than it can stand, the glass will be broken although the pressure may only last for a very short interval of time.” The strength of the glass tubes was found by determining the static pressures required to break similar pieces. It was found that three lengths from the same piece of glass tubing required respectively 890, 950 and 1220 lbs. per square inch to fracture them: the accuracy of the results was therefore not very great. Dixon and Cain estimated that the pressure in the explosion-wave in C 2 N 2 + O 2 lay, probably, between 70 and 120 atmospheres and that in C 2 N 2 O + 2N 2 between 63 and 84 atmospheres. Jones and Bower cast some doubt on the pressures given by Dixon and Cain, and suggested that they were the pressures produced just after detonation had been re-established when the explosion-wave had been damped down at a junction. The pressure in the wave front of the fully established detonation wave in the mixture C 2 N 2 + O 2 was estimated by Jones and Bower to lie between 58 and 75 atmospheres.


1962 ◽  
Vol 5 (4) ◽  
pp. 426 ◽  
Author(s):  
S. A. Berger ◽  
M. Holt

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