Blast Wave Mitigation from the Straight Tube by Using Water Part II - Numerical Simulation

2018 ◽  
Vol 910 ◽  
pp. 78-83 ◽  
Author(s):  
Yuta Sugiyama ◽  
Tomotaka Homae ◽  
Kunihiko Wakabayashi ◽  
Tomoharu Matsumura ◽  
Yoshio Nakayama
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Energy Transfer ◽  
Numerical Simulations ◽  
Blast Wave ◽  
Blast Waves ◽  
Straight Tube ◽  
Water Interface ◽  
Effect Of Water ◽  
Air Water Interface

This paper investigates explosions in a straight square tube in order to understand the mitigation effect of water on blast waves that emerge outside. Numerical simulations are used to assess the effect of water that is put inside the tube. The water reduces the peak overpressure outside, which agrees well with the experimental data. The increases in the kinetic and internal energies of the water are estimated, and the internal energy transfer at the air/water interface is shown to be an important factor in mitigating the blast wave in the present numerical method.

Dispersion of Particles on Liquid Surfaces

2011 ◽  
Author(s):  
Shriram B. Pillapakkam ◽  
Pushpendra Singh
Keyword(s):  
Numerical Simulation ◽  
Particle Size ◽  
Vertical Motion ◽  
Liquid Interface ◽  
Water Interface ◽  
Small Particles ◽  
Air Water Interface ◽  
Large Velocity ◽  
Simulation Results ◽  
Air Liquid Interface

In a recent study we have shown that when small particles, e.g., flour, pollen, glass, etc., contact an air-liquid interface, they disperse rapidly as if they were in an explosion. The rapid dispersion is due to the fact that the capillary force pulls particles into the interface causing them to accelerate to a large velocity. The vertical motion of a particle during its adsorption causes a radially-outward lateral (secondary) flow on the interface that causes nearby particles to move away. We present direct numerical simulation results for the adsorption of particles and show that the inertia of a particle plays an important role in its motion in the direction normal to a fluid-liquid interface. Although the importance of inertia diminishes with decreasing particle size, on an air-water interface the inertia continues to be important even when the size is as small as a few nanometers.

Investigating Pressure Wave Impact on a Surrogate Head Model Using Numerical Simulation Techniques

2019 ◽  
Author(s):  
Rohan Banton ◽  
Thuvan Piehler ◽  
Nicole Zander ◽  
Richard Benjamin ◽  
Josh Duckworth ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Blast Wave ◽  
Military Personnel ◽  
Pressure Wave ◽  
Blast Waves ◽  
Head Model ◽  
Wave Impact ◽  
Simulation Techniques

Abstract There is an urgent need to understand the mechanism leading to mild traumatic brain injury (mTBI) resulting from blast wave impact to the head. The recent conflicts in Iraq and Afghanistan have heightened the awareness of head impact injuries to military personnel resulting from exposure to blast waves [1, 2]. A blast wave generated in air is a by-product of the detonation of an explosive [3]. To date the mechanism resulting in mTBI from primary blast insult is still unclear.

Effect of Additives on J-Aggregate Formation of a Merocyanine and Energy Transfer in Monolayers at the Air−Water Interface

Langmuir ◽  
2002 ◽  
Vol 18 (22) ◽  
pp. 8527-8534 ◽  
Author(s):  
Álvaro Gil ◽  
Inés Arístegui ◽  
Arturo Suárez ◽  
Isabel Sández ◽  
Dietmar Möbius
Keyword(s):  
Energy Transfer ◽  
Water Interface ◽  
Aggregate Formation ◽  
Effect Of Additives ◽  
Air Water Interface

scholarly journals Analysis of Blast Wave Parameters Depending on Air Mesh Size

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Hrvoje Draganić ◽  
Damir Varevac
Keyword(s):  
Numerical Simulations ◽  
Blast Wave ◽  
Large Scale ◽  
Wave Interaction ◽  
Mesh Size ◽  
Blast Waves ◽  
3D Environment ◽  
Close Range ◽  
Blast Wave Propagation ◽  
Optimal Mesh

Results of numerical simulations of explosion events greatly depend on the mesh size. Since these simulations demand large amounts of processing time, it is necessary to identify an optimal mesh size that will speed up the calculation and give adequate results. To obtain optimal mesh sizes for further large-scale numerical simulations of blast wave interactions with overpasses, mesh size convergence tests were conducted for incident and reflected blast waves for close range bursts (up to 5 m). Ansys Autodyn hydrocode software was used for blast modelling in axisymmetric environment for incident pressures and in a 3D environment for reflected pressures. In the axisymmetric environment only the blast wave propagation through the air was considered, and in 3D environment blast wave interaction and reflection of a rigid surface were considered. Analysis showed that numerical results greatly depend on the mesh size and Richardson extrapolation was used for extrapolating optimal mesh size for considered blast scenarios.

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