scholarly journals Performance Study of Shock Tubes with Area Change at the Diaphragm Section : Effects on the Shock Tube Performance of Diaphragm Location, Area Ratio and Convergent Angle

1983 ◽  
Vol 26 (216) ◽  
pp. 958-963 ◽  
Author(s):  
Hiromu SUGIYAMA
1958 ◽  
Vol 3 (05) ◽  
pp. 457 ◽  
Author(s):  
R. A. Alpher ◽  
D. R. White
Keyword(s):  

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.


Author(s):  
Abiy F. Tasissa ◽  
Martin Hautefeuille ◽  
John H. Fitek ◽  
Raúl A. Radovitzky

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.


Author(s):  
N. G. Bykova ◽  
◽  
I. E. Zabelinsky ◽  
P. V. Kozlov ◽  
Yu. V. Tunik ◽  
...  

There are several installations with shock tubes in the world, in which a shock wave in air propagates at a speed close to the second cosmic one. Such velocities are achieved by supplying of high energy (~ 1 MJ) to the pushing gas in the high-pressure chamber.


Author(s):  
B. E. Schmidt ◽  
B. Bobbitt ◽  
N. J. Parziale ◽  
J. E. Shepherd
Keyword(s):  

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
I. da S. Rêgo ◽  
T. Ando ◽  
K. Misumi ◽  
T. Miyazaki ◽  
S. Nishiyori ◽  
...  

A double piston-actuated structure designed for replacing the use of diaphragms in conventional shock tubes has been recently developed. In order to clarify the piston sliding process for this structure, a simplified model based on the motion equation of its main sliding piston has been developed. Calculated piston sliding time against pressure ratio has been numerically obtained and indirectly evaluated by examining the experimental curves of the performance of the diaphragmless structure.


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