Convergence of shock waves between conical and parabolic boundaries
Abstract
Convergence of shock waves, generated by underwater electrical explosions of cylindrical wire arrays, between either parabolic or conical bounding walls is investigated. A highcurrent pulse with a peak of ∼550 kA and rise time of ∼300 ns was applied for the wire array explosion. Strong selfemission from an optical fiber placed at the origin of the implosion was used for estimating the time of flight of the shock wave. 2D hydrodynamic simulations coupled with the equations of state of water and copper showed that the pressure obtained in the vicinity of the implosion is ∼7 times higher in the case of parabolic walls. However, comparison with a spherical wire array explosion showed that the pressure in the implosion vicinity in that case is higher than the pressure in the current experiment with parabolic bounding walls because of strong shock wave reflections from the walls. It is shown that this drawback of the bounding walls can be significantly minimized by optimization of the wire array geometry.
 Authors:
 Physics Department, Technion, Haifa 32000 (Israel)
 Publication Date:
 OSTI Identifier:
 22600023
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physics of Plasmas; Journal Volume: 23; Journal Issue: 7; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; CONVERGENCE; COPPER; CYLINDRICAL CONFIGURATION; EQUATIONS OF STATE; EXPLOSIONS; GEOMETRY; HYDRODYNAMIC MODEL; IMPLOSIONS; OPTICAL FIBERS; OPTIMIZATION; PULSE RISE TIME; SHOCK WAVES; SPHERICAL CONFIGURATION; TIMEOFFLIGHT METHOD; TWODIMENSIONAL CALCULATIONS; UNDERWATER; WALLS; WIRES
Citation Formats
Yanuka, D., Zinowits, H. E., Antonov, O., Efimov, S., Virozub, A., and Krasik, Ya. E. Convergence of shock waves between conical and parabolic boundaries. United States: N. p., 2016.
Web. doi:10.1063/1.4959115.
Yanuka, D., Zinowits, H. E., Antonov, O., Efimov, S., Virozub, A., & Krasik, Ya. E. Convergence of shock waves between conical and parabolic boundaries. United States. doi:10.1063/1.4959115.
Yanuka, D., Zinowits, H. E., Antonov, O., Efimov, S., Virozub, A., and Krasik, Ya. E. 2016.
"Convergence of shock waves between conical and parabolic boundaries". United States.
doi:10.1063/1.4959115.
@article{osti_22600023,
title = {Convergence of shock waves between conical and parabolic boundaries},
author = {Yanuka, D. and Zinowits, H. E. and Antonov, O. and Efimov, S. and Virozub, A. and Krasik, Ya. E.},
abstractNote = {Convergence of shock waves, generated by underwater electrical explosions of cylindrical wire arrays, between either parabolic or conical bounding walls is investigated. A highcurrent pulse with a peak of ∼550 kA and rise time of ∼300 ns was applied for the wire array explosion. Strong selfemission from an optical fiber placed at the origin of the implosion was used for estimating the time of flight of the shock wave. 2D hydrodynamic simulations coupled with the equations of state of water and copper showed that the pressure obtained in the vicinity of the implosion is ∼7 times higher in the case of parabolic walls. However, comparison with a spherical wire array explosion showed that the pressure in the implosion vicinity in that case is higher than the pressure in the current experiment with parabolic bounding walls because of strong shock wave reflections from the walls. It is shown that this drawback of the bounding walls can be significantly minimized by optimization of the wire array geometry.},
doi = {10.1063/1.4959115},
journal = {Physics of Plasmas},
number = 7,
volume = 23,
place = {United States},
year = 2016,
month = 7
}

The convergence of shock waves in water, where the cross section of the boundaries between which the shock wave propagates is either straight or parabolic, was studied. The shock wave was generated by underwater electrical explosions of planar Cu wire arrays using a highcurrent generator with a peak output current of ∼45 kA and rise time of ∼80 ns. The boundaries of the walls between which the shock wave propagates were symmetric along the z axis, which is defined by the direction of the exploding wires. It was shown that with walls having a parabolic cross section, the shock waves converge fastermore »

Convergence of shock waves generated by underwater electrical explosion of cylindrical wire arrays between different boundary geometries
The results of experiments and numerical simulations of a shock wave propagating between either conical or parabolic bounding walls are presented. The shock wave was generated by a microsecond timescale underwater electrical explosion of a cylindrical wire array supplied by a current pulse having an amplitude of ∼230 kA and a rise time of ∼1 μs. It is shown that with the same energy density deposition into the exploding wire array, the shock wave converges faster between parabolic walls, and as a result, the pressure in the vicinity of convergence is ∼2.3 times higher than in the case of conical walls. Themore » 
Propagation of acoustic shock waves between parallel rigid boundaries and into shadow zones
The study of acoustic shock propagation in complex environments is of great interest for urban acoustics, but also for source localization, an underlying problematic in military applications. To give a better understanding of the phenomenon taking place during the propagation of acoustic shocks, laboratoryscale experiments and numerical simulations were performed to study the propagation of weak shock waves between parallel rigid boundaries, and into shadow zones created by corners. In particular, this work focuses on the study of the local interactions taking place between incident, reflected, and diffracted waves according to the geometry in both regular or irregular – alsomore » 
PROPAGATION OF SHOCK WAVES IN A HYDRODYNAMIC CONICAL SHOCK TUBE
Hydrodynamic shock waves were generated in a conical sector shock tube (7 deg ) driven by a 1/2g high explosive charge situated at its vertex. Pressure time histories of the shock waves were obtained with piezoelectric instrumentation. The shape and decay properties of the wave as it progressed down the tube were similar to those of a spherical shock wave generated in free water by a 1/4lb sphere of TNT. The effect of the sector tube in concentrating the explosive energy within a small solid angle is defined by the expression W = Kw sin/sup 2/ (1/2 alpha ), wheremore » 
Flow in conical shock waves: A signal for the deconfinement transition
We investigate the hydrodynamical flow of nuclear matter in a conicalshockwave scenario of a central, asymmetric heavyion collision. This work is motivated by a suggestion of Chapline and Granik that the creation of a deconfined phase of quarks and gluons behind the shock will appreciably increase the deflection angle of the matter flow. We employ several hadron matter equations of state recently suggested to solve the conicalshockwave problem and compare the results with a calculation using the bag equation of state. We find that large differences in the deflection angle obtained in the rest frame of the shock vanish inmore »