Comparison with experiment for TVD calculations of blast waves from a shock tube

1989 ◽  
Vol 9 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Charlie H. Cooke ◽  
Kevin S. Fansler
Keyword(s):  
Shock Tube ◽  
Blast Waves ◽  
Comparison With Experiment

Simulation of blast waves with tailored explosive charges

1985 ◽  
Vol 158 ◽  
pp. 137-152
Author(s):  
M. Sanai ◽  
H. E. Lindberg ◽  
J. D. Colton
Keyword(s):  
Shock Tube ◽  
Charge Density ◽  
Cost Effective ◽  
Development Programme ◽  
Blast Waves ◽  
Charge Density Distribution ◽  
Test Conditions ◽  
Order Of Magnitude ◽  
Explosive Charges ◽  
Simulation Time

We have developed a compact and cost-effective shock tube to simulate the static and dynamic pressures of blast waves. The shock tube is open at both ends and is driven by high explosives distributed over a finite length of the tube near one end. The overall charge length is determined by the simulation time of interest, and the charge-density distribution is tailored to produce the pressure-waveform shape desired. For the shock tube to simulate a typical blast wave, the charge density must be highest at the charge front (closest to the test section) and gradually reduced towards the back. The resulting shock tube is an order of magnitude shorter than a conventional dynamic airblast simulator (DABS) in which concentrated explosives are used to drive the shock.Tailored charges designed using this method were built and tested in a simulation development programme sponsored by the U.S. Defense Nuclear Agency (DNA). The pressures measured for several charge distributions agreed very well with SRI's PUFF hydrocode computations and demonstrated the feasibility of the compact simulator under realistic test conditions.

scholarly journals On the formation of Friedlander waves in a compressed-gas-driven shock tube

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150611 ◽  
Author(s):  
Abiy F. Tasissa ◽  
Martin Hautefeuille ◽  
John H. Fitek ◽  
Raúl A. Radovitzky
Keyword(s):  
Shock Tube ◽  
Analytical Model ◽  
Blast Waves ◽  
Rational Approach ◽  
Initial Structure ◽  
Shock Tubes ◽  
Rarefaction Waves ◽  
Wave Interactions ◽  
Compressed Gas ◽  
Volume Method

Compressed-gas-driven shock tubes have become popular as a laboratory-scale replacement for field blast tests. The well-known initial structure of the Riemann problem eventually evolves into a shock structure thought to resemble a Friedlander wave, although this remains to be demonstrated theoretically. In this paper, we develop a semi-analytical model to predict the key characteristics of pseudo blast waves forming in a shock tube: location where the wave first forms, peak over-pressure, decay time and impulse. The approach is based on combining the solutions of the two different types of wave interactions that arise in the shock tube after the family of rarefaction waves in the Riemann solution interacts with the closed end of the tube. The results of the analytical model are verified against numerical simulations obtained with a finite volume method. The model furnishes a rational approach to relate shock tube parameters to desired blast wave characteristics, and thus constitutes a useful tool for the design of shock tubes for blast testing.

Shock Tube Design for High Fidelity Blast Wave Simulation

2015 ◽  
Author(s):  
Christopher Ostoich ◽  
Mark Rapo ◽  
Brian Powell ◽  
Humberto Sainz ◽  
Philemon Chan
Keyword(s):  
Shock Tube ◽  
Blast Wave ◽  
Laboratory Data ◽  
Blast Waves ◽  
High Fidelity ◽  
Ongoing Research ◽  
Wave Simulation ◽  
Blast Overpressure ◽  
Blast Exposure ◽  
Significant Pathway

Traumatic brain injury (TBI) has been recognized as the signature wound of the current conflicts and it has been hypothesized that blast overpressure can contribute a significant pathway to TBI. As such, there are many ongoing research efforts to understand the mechanism to blast induced TBI, which all require blast testing using physical and biological surrogates either in the field or in the laboratory. The use of shock tubes to generate blast-like pressure waves in a laboratory can effectively produce the large amounts of data needed for research into blast induced TBI. A combined analytical, computational, and experimental approach was developed to design an advanced shock tube capable of generating high quality out-of-tube blast waves. The selected tube design was fabricated and laboratory tests at various blast wave levels were conducted. Comparisons of tube-generated laboratory data with explosive-generated field data indicated that the shock tube could accurately reproduce blast wave loading on test surrogates. High fidelity blast wave simulation in the laboratory presents an avenue to rapidly and inexpensively generate the large volumes of data necessary to validate and develop theories linking blast exposure to TBI.

Generation and Analysis of Blast Waves from a Compressed Air-Driven Shock Tube

2008 ◽  
Author(s):  
Daniel Kirk ◽  
Joel Faure ◽  
Hector Gutierrez ◽  
Stanislav Svetlov ◽  
Ronald Hayes ◽  
...  
Keyword(s):  
Shock Tube ◽  
Blast Waves ◽  
Compressed Air

Experimental and Numerical Investigation of Blast Wave Interaction With a Three Level Building

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Jacques Massoni ◽  
Laurent Biamino ◽  
Georges Jourdan ◽  
Ozer Igra ◽  
Lazhar Houas
Keyword(s):  
Shock Tube ◽  
Blast Wave ◽  
Wave Interaction ◽  
Wave Pattern ◽  
Blast Waves ◽  
Building Model ◽  
Experimental Part ◽  
Level Building ◽  
Blast Wave Interaction ◽  
Good Agreement

The present work shows that weak blast waves that are considered as being harmless can turn to become fatal upon their reflections from walls and corners inside a building. In the experimental part, weak blast waves were generated by using an open-end shock tube. A three level building model was placed in vicinity to the open-end of the used shock tube. The evolved wave pattern inside the building rooms was recorded by a sequence of schlieren photographs; also pressure histories were recorded on the rooms' walls. In addition, numerical simulations of the evolved flow field inside the building were conducted. The good agreement obtained between numerical and experimental results shows the potential of the used code for identifying safe and dangerous places inside the building rooms penetrated by the weak blast wave.

Methodology to Study Attenuation of a Blast Wave Through the Cranium

2011 ◽  
Author(s):  
Alok S. Shah ◽  
Brian D. Stemper ◽  
Narayan Yoganandan ◽  
Frank A. Pintar ◽  
Nagarajan Rangarajan ◽  
...  
Keyword(s):  
Finite Element ◽  
Shock Tube ◽  
Open Field ◽  
Sampling Rate ◽  
Blast Waves ◽  
Membrane Thickness ◽  
Finite Element Models ◽  
Ipsilateral Side ◽  
Injury Mechanisms ◽  
Neck Pressure

The purpose of the study was to quantify attenuation of open field shockwaves passing through the PMHS (Post Mortem Human Subject) cranium. A better understanding of the relationship between shockwave characteristics external to the cranium and insults experienced by the brain is essential for understanding injury mechanisms, validation of finite element models, and development of military safety devices for soldiers in the field. These relationships are being developed using experimental PMHS techniques. Our existing shock tube produced open field shockwaves by increasing input pressure behind a Mylar membrane using compressed nitrogen until the membrane burst. Increasing membrane thickness resulted in greater bursting pressure and peak shockwave pressure. Peak pressure decreased predictably with greater distance from the shock tube outlet. Input pressures between 1.6 and 3.2 MPa resulted in peak shockwave pressures between 45 kPa and 90 kPa measured between 40 and 60 cm from the shock tube exit. The experimental protocol consisted of obtaining a PMHS head, filling the voided cranium with Sylgard gel, and securing the head in front of the shock tube using a Hybrid III dummy neck. Pressure transducers were mounted on the external cranium surface on the ipsilateral side and on the internal cranium surface on the ipsilateral and contralateral sides. Because the specimen was tested in multiple orientations, the ipsilateral side referred to the frontal or temporal sides. Transducers were mounted prior to adding the Sylgard gel. Data from all tests indicated shockwave rise times less than 10 μs external to the skull and internal to the skull on the ipsilateral side. Therefore, the sampling rate was 10 MHz using a digital oscilloscope. Shockwave characteristics were quantified including peak overpressure, peak underpressure, and duration of positive phase. The results show peak overpressure attenuations between 14 and 26% from the external ipsilateral transducer to the contralateral transducers in frontal and lateral orientation. In addition, there was a 93–96% reduction in the rate of onset between those transducers. Each characteristic may affect injury type/severity. This setup can be used to understand injury mechanisms for blast-induced mTBI, to quantify effects of interventions (e.g., helmets) on attenuation of open field blast waves, and for validation of finite element models.

Generation and Analysis of Blast Waves from a Compressed Air-Driven Shock Tube

2008 ◽  
Author(s):  
Daniel Kirk ◽  
Joel Faure ◽  
Hector Gutierrez ◽  
Stanislav Svetlov ◽  
Ronald Hayes ◽  
...  
Keyword(s):  
Shock Tube ◽  
Blast Waves ◽  
Compressed Air

scholarly journals Shock tube design for high intensity blast waves for laboratory testing of armor and combat materiel

2014 ◽  
Vol 10 (2) ◽  
pp. 245-250 ◽  
Author(s):  
Elijah Courtney ◽  
Amy Courtney ◽  
Michael Courtney
Keyword(s):  
Shock Tube ◽  
High Intensity ◽  
Laboratory Testing ◽  
Blast Waves

Some Consideration on the Aerodynamic Design of Blast Wave Simulator Using a Shock Tube System

2019 ◽  
Author(s):  
Suguru Kushida ◽  
Kengo Asada ◽  
Kozo Fujii ◽  
Tomoaki Tatsukawa ◽  
Kazuyuki Sakamoto
Keyword(s):  
Shock Tube ◽  
Blast Wave ◽  
Nozzle Exit ◽  
Jet Flow ◽  
Blast Waves ◽  
Aerodynamic Design ◽  
Computational Simulations ◽  
Tube System ◽  
Reduction Methods ◽  
Driver Section

Abstract Reduction methods of the jet flow associated with simulated blast waves by blast wave simulators are investigated by computational simulations. First, the cause of the jet flow is discussed. After that, the influence of the nozzle angle and the volume of the driver section on the jet flow are investigated. The obtained results show that the jet flow is caused by vortices which are generated at the edge of the nozzle and that the jet can be reduced by decreasing the driver section. Furthermore, the nozzle with the moderate angle reduces the jet flow near the nozzle exit and the nozzle with the widest angle reduces the jet flow far from the nozzle exit. These results indicate reducing the driver section and using the proper nozzle angle according to the distance from the nozzle exit are effective for reducing the jet flow.

Shock Tube Simulation of Low Mach Number Blast Waves

2015 ◽  
pp. 83-88
Author(s):  
R. G. Morgan ◽  
D. E. Gildfind
Keyword(s):  
Mach Number ◽  
Shock Tube ◽  
Blast Waves ◽  
Low Mach Number
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