Study of Two Cylindrical Water Columns Subjected to Planar Shock Wave Loading

2000 ◽  
Author(s):  
D. Igra ◽  
K. Takayama
Keyword(s):  
Shock Wave ◽  
Drag Coefficient ◽  
Water Column ◽  
Reynolds Numbers ◽  
Flow Conditions ◽  
Planar Shock ◽  
Water Columns ◽  
Planar Shock Wave ◽  
Shock Tube Test ◽  
Double Exposure Holographic Interferometry

Abstract Two water columns with identical initial diameters of 4.8 mm were placed 30 mm apart inside a shock tube test section and loaded by a shock wave of Mach number 1.47 in atmospheric air. The Weber and Reynolds numbers corresponding to these flow conditions are 6,900 and 112,000, respectively. Double exposure holographic interferometry was used to visualize the shock/water columns interaction. The process of the water columns deformation, displacement, acceleration was well visualized and hence the drag coefficient of shock loaded water columns was evaluated. The water column in the front behaved virtually the same as a single water column. However the displacement and acceleration of the rear water column was less significant than that of the front one. Hence its drag coefficient is less. These results show that the frontal water column has affected the flow field around the rear water column.

Experimental Investigation of Two Cylindrical Water Columns Subjected to Planar Shock Wave Loading

2003 ◽  
Vol 125 (2) ◽  
pp. 325-331 ◽  
Author(s):  
D. Igra ◽  
K. Takayama
Keyword(s):  
Shock Wave ◽  
Drag Coefficient ◽  
Water Column ◽  
Reynolds Numbers ◽  
Flow Conditions ◽  
Planar Shock ◽  
Water Columns ◽  
Planar Shock Wave ◽  
Shock Tube Test ◽  
Double Exposure Holographic Interferometry

Two water columns with identical initial diameters of 4.8 mm were placed 30 mm apart inside a shock tube test section and were loaded by a shock wave of Mach number 1.47 in atmospheric air. The Weber and Reynolds numbers corresponding to these flow conditions are 6900 and 112,000, respectively. Double-exposure holographic interferometry was used to visualize the shock/water columns interaction. The process of the water columns deformation, displacement, and acceleration was well visualized and hence the drag coefficient of shock loaded water columns was evaluated. The front water column behaved virtually the same as a single water column under the same flow conditions. However, the displacement and acceleration of the rear water column was less significant than that of the front one. Hence, its drag coefficient is less. These results show that the front water column has affected the flow field around the rear water column.

scholarly journals Planar shock wave sliding over a water layer

2016 ◽  
Vol 57 (8) ◽  
Author(s):  
V. Rodriguez ◽  
G. Jourdan ◽  
A. Marty ◽  
A. Allou ◽  
J.-D. Parisse
Keyword(s):  
Shock Wave ◽  
Water Layer ◽  
Planar Shock ◽  
Planar Shock Wave

Flow of a planar shock wave around a thermal layer at a rigid wall

1991 ◽  
Vol 31 (3) ◽  
pp. 354-361
Author(s):  
B. I. Zaslavskii ◽  
S. Yu. Morozkin ◽  
A. A. Prokof'ev ◽  
V. R. Shlegel'
Keyword(s):  
Shock Wave ◽  
Rigid Wall ◽  
Planar Shock ◽  
Planar Shock Wave ◽  
Thermal Layer

Specifics of generating explosively formed projectiles of variable shape from metal liners

2019 ◽  
Author(s):  
P.V. Kruglov ◽  
V.I. Kolpakov ◽  
I.A. Bolotina
Keyword(s):  
Shock Wave ◽  
Aspect Ratio ◽  
Detonation Wave ◽  
Variable Shape ◽  
Internal Surfaces ◽  
Planar Shock ◽  
Wave Generator ◽  
Planar Shock Wave ◽  
Metal Liner ◽  
A Charge

We propose using charges generating explosively formed projectiles of variable shape to remotely demolish structurally unsound concrete or brick walls of buildings and other structures. The paper considers the charges required, their design and operation. The operation of such a charge involves the explosive material accelerating a metal liner, covering a distance of up to several hundred charge diameters. The metal liner deforms while moving and assumes a compact shape. We used variable thickness copper liners, the external and internal surfaces of which are formed by a combination of spherical surfaces. A planar shock wave generator featuring a variable detonation wave slope is considered as the initiation system for the charge. We present the results of numerically simulating our explosive charge operation in order to determine how charge parameters affect performance. We estimated charge performance via two projectile parameters: its shape and velocity. The study also evaluated the effect of the planar shock wave generator slope on the projectile shape. We obtained projectile velocity and aspect ratio as functions of the slope of the converging detonation wave. We determined that decreasing the slope of the converging detonation wave front leads to an increase in the aspect ratio and velocity of the explosively formed projectile.

Experimental and theoretical study of shock wave propagation through double-bend ducts

2001 ◽  
Vol 437 ◽  
pp. 255-282 ◽  
Author(s):  
O. IGRA ◽  
X. WU ◽  
J. FALCOVITZ ◽  
T. MEGURO ◽  
K. TAKAYAMA ◽  
...  
Keyword(s):  
Shock Wave ◽  
Wave Attenuation ◽  
Wave Pattern ◽  
Complex Flow ◽  
Shock Wave Attenuation ◽  
Planar Shock ◽  
Wave Patterns ◽  
Planar Shock Wave ◽  
Flow Evolution ◽  
Interferometric Study

The complex flow and wave pattern following an initially planar shock wave transmitted through a double-bend duct is studied experimentally and theoretically/numerically. Several different double-bend duct geometries are investigated in order to assess their effects on the accompanying flow and shock wave attenuation while passing through these ducts. The effect of the duct wall roughness on the shock wave attenuation is also studied. The main flow diagnostic used in the experimental part is either an interferometric study or alternating shadow–schlieren diagnostics. The photos obtained provide a detailed description of the flow evolution inside the ducts investigated. Pressure measurements were also taken in some of the experiments. In the theoretical/numerical part the conservation equations for an inviscid, perfect gas were solved numerically. It is shown that the proposed physical model (Euler equations), which is solved by using the second-order-accurate, high-resolution GRP (generalized Riemann problem) scheme, can simulate such a complex, time-dependent process very accurately. Specifically, all wave patterns are numerically simulated throughout the entire interaction process. Excellent agreement is found between the numerical simulation and the experimental results. The efficiency of a double-bend duct in providing a shock wave attenuation is clearly demonstrated.

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