Initial Moving Simulation of Densely-Packed Particles Driven by Planar Shock Wave

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.

Download Full-text

Numerical simulation of the reflection of a planar shock wave over a double wedge

International Journal for Numerical Methods in Fluids ◽

10.1002/fld.1650130906 ◽

1991 ◽

Vol 13 (9) ◽

pp. 1153-1170 ◽

Cited By ~ 9

Author(s):

K. Itoh ◽

K. Takayama ◽

G. Ben-Dor

Keyword(s):

Numerical Simulation ◽

Shock Wave ◽

Double Wedge ◽

Planar Shock ◽

Planar Shock Wave

Download Full-text

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

Journal of Fluid Mechanics ◽

10.1017/s0022112001004098 ◽

2001 ◽

Vol 437 ◽

pp. 255-282 ◽

Cited By ~ 46

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.

Download Full-text