Blast Mitigation by Water Mist (2) Shock Wave Mitigation Using Glass Particles and Water Droplets in Shock Tubes

Author(s):  
Douglas Schwer ◽  
K. Kailasanath
2006 ◽  
Author(s):  
Jean L. Bailey ◽  
John P. Farley ◽  
Frederick W. Williams ◽  
Michael S. Lindsay ◽  
Douglas A. Schwer
Keyword(s):  

2002 ◽  
Vol 9 (2) ◽  
pp. 721-723 ◽  
Author(s):  
Daniel Bivolaru ◽  
S. P. Kuo

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5850
Author(s):  
Hassan Raza Shah ◽  
Kun Wang ◽  
Xu Qing Lang ◽  
Jing Wu Wang ◽  
Jing Jun Wang ◽  
...  

Recently, water has been employed as a supportive agent for the preparation of multiple suppressing agents including aqueous film forming foams (AFFF), which is combined with different kinds of gases for its various applications. In this study, the water mist is chosen for the gas-suppressing agent such as carbon dioxide. Our work investigated the suppression effects of water droplets on the n-heptane pool fire, and its mixture with carbon dioxide, respectively. The size and frequency of droplets with their effect on temperature and suppression was compared to observe the difference in the suppression. Initially, it was found that the droplets having a larger droplet size were found to be more efficient as compared to the smaller droplets with respect to the heat release rate, temperature, and radiation. Afterwards, a mixture of water droplets and carbon dioxide was simultaneously discharged to compare the difference between these two suppressing agents. It was found that the synergistic effect of the mixture has higher advantages over the use of only water suppression. It helps reduce the hot gases that surround the pool fire and allows the water mist to travel efficiently towards the fuel. Both suppression mechanisms were set to similar initial parameters that lead to different outcomes.


2018 ◽  
pp. 279-297
Author(s):  
C. Breda ◽  
S. Kerampran ◽  
M.-O. Sturtzer ◽  
M. Arrigoni ◽  
J.-F. Legendre

Shock Waves ◽  
2012 ◽  
Vol 23 (1) ◽  
pp. 91-101 ◽  
Author(s):  
A. Chaudhuri ◽  
A. Hadjadj ◽  
O. Sadot ◽  
G. Ben-Dor

Author(s):  
Chong Whang ◽  
Warren Chilton ◽  
Philemon Chan

A computational fluid dynamics (CFD) study was carried out with data comparison to provide guidance for the control of open shock tube wave expansion to simulate field blast loadings for the conduct of biomechanical blast overpressure tests against surrogate test models. The technique involves the addition of a diffuser to the shock tube to prevent overexpansion before the shock wave impacts the test model. Mild traumatic brain injury (mTBI) has been identified as the signature injury for the conflicts in Iraq and Afghanistan, and blast overpressure from improvised explosive devices (IEDs) has been hypothesized as a significant mTBI risk factor. Research in the understanding of the mechanism of blast induced mTBI has been very active, which requires blast testing using animal and physical models. Full scale field blast testing is expensive. The use of shock tubes is clearly a viable cost effective laboratory method with many advantages. CFD simulations with data comparison show that without a diffuser, the shock wave exiting the tube tends to over expand producing an incident waveform with a short positive duration followed by a significant negative phase that is different from a Friedlander wave. However, the overexpansion effects can be mitigated by a diffuser. Shock tube tests also support the simulation results in which a diffuser improves the waveform from the shock tube. CFD simulations were validated by shock tube tests.


2015 ◽  
Vol 20 (2) ◽  
pp. 49-54
Author(s):  
Iuliana Florina Pană ◽  
Luminiţa Cristina Alil ◽  
Florin Ilie

Abstract The main application of underwater detonation since the Second World War is to destroy military ships. Nowadays, a lot of studies are performed in order to discover a controlled and safe application of shock waves through different media. The paper presents the results of a research on a bubble curtain behaviour subjected to shock waves generated by an underwater TNT blast. The main objective was to analyze the mitigation solution of underwater explosion effects by means of gas bubbles. Simulations using ANSYS AUTODYN and explicit dynamics procedures were performed on a 3D model, in order to better understand the physical process of formation and propagation of a shock wave in the biphasic medium which represents the purpose of many researchers. The numerical simulations were performed taking into account the interaction between a shock wave and the bubble curtain considering a random distribution in space and bubble dimensions.


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