Observations of Shock Waves in an Electrically Driven Shock Tube

1964 ◽  
Vol 7 (6) ◽  
pp. 906 ◽  
Author(s):  
H. G. Ahlstrom ◽  
D. W. Mahaffey ◽  
L. Sanga ◽  
R. I. Schoen
Keyword(s):  
Shock Waves ◽  
Shock Tube

Generation of Cylindrical Converging Shock Waves in a Conventional Shock Tube

2015 ◽  
pp. 1077-1082 ◽  
Author(s):  
L. Biamino ◽  
G. Jourdan ◽  
C. Mariani ◽  
L. Houas ◽  
M. Vandenboomgaerde ◽  
...  
Keyword(s):  
Shock Waves ◽  
Shock Tube ◽  
Converging Shock Waves

Shock-initiated exothermic reactions. VI. The oxidation of ethylene oxide and cyclopropane

1969 ◽  
Vol 22 (7) ◽  
pp. 1355 ◽  
Author(s):  
LJ Drummond ◽  
J Kikkert
Keyword(s):  
Shock Waves ◽  
Ethylene Oxide ◽  
Shock Tube ◽  
Induction Period ◽  
Ignition Delay ◽  
Exothermic Reactions ◽  
Induction Periods ◽  
Reflected Shock ◽  
Formaldehyde Oxidation ◽  
Temperature Dependences

Mixtures of ethylene oxide or cyclopropane with oxygen and argon were ignited with reflected shock waves In a shock tube. The temperature dependences of the ignition delay and the growth of light emitted during the induction period to explosion of C2H4O-O2 mixtures indicate that the rate-controlling reaction is that of formaldehyde oxidation. The temperature dependence of induction periods for C3H6-O2 mixtures suggests that a complicated but undetermined mechanism controls the delay to ignition.

scholarly journals Shock Loading of Closed Cell Aluminum Foams in the Presence of an Air Cavity

2020 ◽  
Vol 10 (12) ◽  
pp. 4128
Author(s):  
Mahesh Thorat ◽  
Shiba Sahu ◽  
Viren Menezes ◽  
Amol Gokhale ◽  
Hamid Hosano
Keyword(s):  
Shock Waves ◽  
Shock Tube ◽  
Shock Loading ◽  
Pressure Rise ◽  
Incident Shock ◽  
Foam Density ◽  
Aluminum Foams ◽  
Closed Cell ◽  
Rigid Walls ◽  
End Wall

It is important to protect assets located within cavities vulnerable to incident shock waves generated by explosions. The aim of the present work is to explore if closed cell aluminum foams can mediate and attenuate incident shocks experienced by cavities. A small cavity of 9 mm diameter and 2 mm length was created within the steel end-wall of a shock tube and exposed to shocks, directly or after isolating by aluminum foam liners. Shock waves with incident pressure of 9–10 bar travelling at a velocity of 1000–1050 m/s were generated in the shock tube. Compared to the no-foam condition, the pressure induced in the cavity was either equal or lower, depending on whether the foam density was low (0.28 g/cc) or high (0.31 to 0.49 g/cc), respectively. Moreover, the rate of pressure rise, which was very high without and with the low density foam barrier, reduced substantially with increasing foam density. Foams deformed plastically under shock loading, with the extent of deformation decreasing with increasing foam density. Some interesting responses such as perforation of cell walls in the front side and densification in the far side of the foam were observed by a combination of scanning electron microscopy and X-ray microscopy. The present work conclusively shows that shocks in cavities within rigid walls can be attenuated by using foam liners of sufficiently high densities, which resist densification and extrusion into the cavities. Even such relatively high-density foams would be much lighter than fully dense materials capable of protecting cavities from shocks.

scholarly journals A Shock Tube Study on Nonequilibrium Radiation of Strong Shock Waves in Low-Density Air.

1998 ◽  
Vol 41 (2) ◽  
pp. 390-396 ◽  
Author(s):  
Hiroki HONMA ◽  
Toshihiro MORIOKA ◽  
Nariaki SAKURAI ◽  
Kazuo MAENO
Keyword(s):  
Shock Waves ◽  
Shock Tube ◽  
Strong Shock ◽  
Low Density ◽  
Nonequilibrium Radiation ◽  
Strong Shock Waves ◽  
Tube Study

Effects of Shock Waves on Acceleration of Cell Growth Rate by Shock Tube

2008 ◽  
Author(s):  
Masaaki Tamagawa ◽  
Norikazu Ishimatsu
Keyword(s):  
Shock Wave ◽  
Growth Rate ◽  
Endothelial Cells ◽  
Shock Waves ◽  
Shock Tube ◽  
Test Case ◽  
Plane Shock ◽  
Extracorporeal Shock Wave ◽  
Shock Wave Pressure

This paper describes effects of shock waves on cells to certificate the angiogenesis by shock wave (pressure wave) in the clinical application such as ESW (Extracorporeal Shock Wave). Especially, to investigate the effects of shock waves on the endothelial cells in vitro, the cells worked by plane shock waves using shock tube apparatus are observed and measured in the microscope. The peak pressure working on the endothelial cells at the test case is 0.4 MPa. After working shock waves on suspended cells, growth rate (area per one cell and population of cells) are measured by image processing. It is found that the growth rate of the shock-worked cells from 0 to 4h is clearly high compared with control one. It is concluded that once shock waves worked, the cells have capacity to increase growth rate in vitro. This preliminary result will be applied to fundamental investigations about shock wave stimulus on several kinds of cells in future.

Development of a Large Diameter Diaphragmless Shock Tube for Gas-Dynamic Laser Studies

2007 ◽  
Vol 566 ◽  
pp. 9-14 ◽  
Author(s):  
I. da S. Rego ◽  
K.N. Sato ◽  
S. Kugimiya ◽  
T. Aoki ◽  
Y. Miyoshi ◽  
...  
Keyword(s):  
Shock Waves ◽  
Shock Tube ◽  
Large Diameter ◽  
Gaseous Mixtures ◽  
Gas Dynamic ◽  
Diaphragmless Shock Tube ◽  
Good Accordance ◽  
Basic Characteristics ◽  
And Performance

This paper reports on the design and performance of a large diameter diaphragmless shock tube that has been recently developed in order to experimentally study various basic characteristics of the gas-dynamic laser (GDL). The main engineering element of the shock tube is a diaphragm-like sliding piston (in place of a rupturing diaphragm) by which normal shock waves are formed. The role of such a structure in generating repeatable shock waves is discussed. The shock tube performs in good accordance with the simple shock tube theory, as has been verified so far by experiments with some conventional lasing gases (gaseous mixtures of CO2 and N2 and those diluted with an excess of He) at shock wave Mach numbers ranging from 1 to 5. Recent results of the stagnation conditions achieved in the shock tube with application to GDL experiments are included as well.

SPECTROSCOPIC TEMPERATURE MEASUREMENTS IN A SHOCK TUBE USING CN AS A THERMOMETRIC MOLECULE

1960 ◽  
Vol 38 (6) ◽  
pp. 715-719 ◽  
Author(s):  
W. H. Parkinson ◽  
R. W. Nicholls
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Shock Tube ◽  
Wave Velocity ◽  
Dynamic Theory ◽  
Shock Wave Velocity ◽  
Velocity Measurements ◽  
Shock Excitation ◽  
Intensity Measurements ◽  
Gas Dynamic

Rotational intensity measurements on the CN spectrum, excited through shock excitation of a powdered mixture of NH4Cl, KNO2, and C by helium-driven shock waves in argon have been used to infer "rotational temperatures" of the gas between 6350 °K and 8750 °K. The measured values agree well with gas kinetic temperatures inferred from simple gas dynamic theory and shock-wave velocity measurements.

scholarly journals Experimental investigation of cylindrical converging shock waves interacting with a polygonal heavy gas cylinder

2015 ◽  
Vol 784 ◽  
pp. 225-251 ◽  
Author(s):  
Ting Si ◽  
Tong Long ◽  
Zhigang Zhai ◽  
Xisheng Luo
Keyword(s):  
Shock Waves ◽  
Shock Tube ◽  
High Speed ◽  
Initial Conditions ◽  
Laser Sheet ◽  
Imaging Method ◽  
Gas Cylinder ◽  
Diaphragmless Shock Tube ◽  
Converging Shock Waves ◽  
Heavy Gas

The interaction of cylindrical converging shock waves with a polygonal heavy gas cylinder is studied experimentally in a vertical annular diaphragmless shock tube. The reliability of the shock tube facility is verified in advance by capturing the cylindrical shock movements during the convergence and reflection processes using high-speed schlieren photography. Three types of air/SF6 polygonal interfaces with cross-sections of an octagon, a square and an equilateral triangle are formed by the soap film technique. A high-speed laser sheet imaging method is employed to monitor the evolution of the three polygonal interfaces subjected to the converging shock waves. In the experiments, the Mach number of the incident cylindrical shock at its first contact with each interface is maintained to be 1.35 for all three cases. The results show that the evolution of the polygonal interfaces is heavily dependent on the initial conditions, such as the interface shapes and the shock features. A theoretical model for circulation initially deposited along the air/SF6 polygonal interface is developed based on the theory of Samtaney & Zabusky (J. Fluid Mech., vol. 269, 1994, pp. 45–78). The circulation depositions along the initial interface result in the differences in flow features among the three polygonal interfaces, including the interface velocities and the perturbation growth rates. In comparison with planar shock cases, there are distinct phenomena caused by the convergence effects, including the variation of shock strength during imploding and exploding (geometric convergence), consecutive reshocks on the interface (compressibility), and special behaviours of the movement of the interface structures (phase inversion).

scholarly journals Interaction of Shock Waves with Discrete Gas Inhomogeneities: A Smoothed Particle Hydrodynamics Approach

2019 ◽  
Vol 9 (24) ◽  
pp. 5435 ◽  
Author(s):  
Andrea Albano ◽  
Alessio Alexiadis
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Shock Tube ◽  
Smoothed Particle Hydrodynamics ◽  
Particle Hydrodynamics ◽  
Interaction Of Shock Waves ◽  
Smoothed Particle ◽  
Different Shapes ◽  
The Difference

In this study, we propose a smoothed particle hydrodynamics model for simulating a shock wave interacting with cylindrical gas inhomogeneities inside a shock tube. When the gas inhomogeneity interacts with the shock wave, it assumes different shapes depending on the difference in densities between the gas inhomogeneity and the external gas. The model uses a piecewise smoothing length approach and is validated by comparing the results obtained with experimental and CFD data available in the literature. In all the cases considered, the evolution of the inhomogeneity is similar to the experimental shadowgraphs and is at least as accurate as the CFD results in terms of timescale and shape of the gas inhomogeneity.

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