Mach reflection of a H2-O2-Ar detonation wave on the rough wedge based on soot track measurements

2021 ◽  
Vol 225 ◽  
pp. 364-376
Author(s):  
Zhi Zhang ◽  
Changjian Wang ◽  
Xinjiao Luo ◽  
Yongzhi Guo ◽  
Yang Wan ◽  
...  
2008 ◽  
Vol 599 ◽  
pp. 81-110 ◽  
Author(s):  
C. J. WANG ◽  
S. L. XU ◽  
C. M. GUO

Gaseous detonation propagation in a bifurcated tube was experimentally and numerically studied for stoichiometric hydrogen and oxygen mixtures diluted with argon. Pressure detection, smoked foil recording and schlieren visualization were used in the experiments. Numerical simulation was carried out at low initial pressure (8.00kPa), based on the reactive Navier–Stokes equations in conjunction with a detailed chemical reaction model. The results show that the detonation wave is strongly disturbed by the wall geometry of the bifurcated tube and undergoes a successive process of attenuation, failure, re-initiation and the transition from regular reflection to Mach reflection. Detonation failure is attributed to the rarefaction waves from the left-hand corner by decoupling leading shock and reaction zones. Re-initiation is induced by the inert leading shock reflection on the right-hand wall in the vertical branch. The branched wall geometry has only a local effect on the detonation propagation. In the horizontal branch, the disturbed detonation wave recovers to a self-sustaining one earlier than that in the vertical branch. A critical case was found in the experiments where the disturbed detonation wave can be recovered to be self-sustaining downstream of the horizontal branch, but fails in the vertical branch, as the initial pressure drops to 2.00kPa. Numerical simulation also shows that complex vortex structures can be observed during detonation diffraction. The reflected shock breaks the vortices into pieces and its interaction with the unreacted recirculation region induces an embedded jet. In the vertical branch, owing to the strength difference at any point and the effect of chemical reactions, the Mach stem cannot be approximated as an arc. This is different from the case in non-reactive steady flow. Generally, numerical simulation qualitatively reproduces detonation attenuation, failure, re-initiation and the transition from regular reflection to Mach reflection observed in experiments.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Yusong Miao ◽  
Xiaojie Li ◽  
HongHao Yan ◽  
Xiaohong Wang ◽  
Junpeng Sun

It is difficult to use industrial explosives to excavate hard rock and achieve suitable blasting effect due to the low energy utilization rate resulting in large rocks and short blasting footage. Thus, improving the utilization ratio of the explosive energy is important. In this study, a novel bilinear initiation system based on hard rock blasting was proposed to improve the blasting effects. Furthermore, on the basis of the detonation wave collision theory, frontal collision, oblique reflection, and Mach reflection during detonation wave propagation were studied. The results show that the maximum detonation pressure at the Mach reflection point where the incident angle is 46.9° is three times larger than the value of the explosive complete detonation. Then, in order to analyze the crack propagation in different initiation forms, a rock fracture test slot was designed, and the results show that bilinear initiating system can change the energy distribution of explosives. Finally, field experiment was implemented at the hard rock pile blasting engineering, and experimental results show that the present system possesses high explosive energy utilization ratio and low rock fragments size. The results of this study can be used to improve the efficiency in hard rock blasting.


Shock Waves ◽  
2015 ◽  
Vol 25 (3) ◽  
pp. 293-304 ◽  
Author(s):  
J. Li ◽  
J. Ning ◽  
J. H. S. Lee

2002 ◽  
Vol 12 (7) ◽  
pp. 403-412 ◽  
Author(s):  
P. A. Fomin ◽  
K. Mitropetros ◽  
H. Hieronymus ◽  
J. Steinbach

1987 ◽  
Vol 48 (C4) ◽  
pp. C4-119-C4-124
Author(s):  
H. N. PRESLES ◽  
P. BAUER ◽  
C. GUERRAUD ◽  
D. DESBORDES

Author(s):  
S. M. FROLOV ◽  
◽  
V. I. ZVEGINTSEV ◽  
V. S. AKSENOV ◽  
I. V. BILERA ◽  
...  

The term "detonability" with respect to fuel-air mixtures (FAMs) implies the ability of a reactive mixture of a given composition to support the propagation of a stationary detonation wave in various thermodynamic and gasdynamic conditions. The detonability of FAMs, on the one hand, determines their explosion hazards during storage, transportation, and use in various sectors of the economy and, on the other hand, the possibility of their practical application in advanced energy-converting devices operating on detonative pressure gain combustion.


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