Solidification Effects on the Fragmentation of Molten Metal Drops Behind a Pressure Shock Wave

1987 ◽  
Vol 109 (1) ◽  
pp. 226-231 ◽  
Author(s):  
J. W. Yang ◽  
S. G. Bankoff

Molten Wood’s metal drops falling through water fragment upon being overtaken by a shock wave, under conditions of simultaneous surface solidification. The study of this fragmentation is the subject of the present paper. If the solid crust thickness is sufficiently large by the time of the shock arrival, fine-scale fragmentation is prevented. A stability theory (Epstein, 1977) which includes the elastic crust stiffness in the pressure boundary conditions, and a nonlinear Taylor instability theory (Cooper and Dienes, 1977), are both surprisingly successful in predicting the threshold for fragmentation inhibition.

1996 ◽  
Vol 14 (2) ◽  
pp. 157-169 ◽  
Author(s):  
Yuan Gu ◽  
Sizu Fu ◽  
Jiang Wu ◽  
Songyu Yu ◽  
Yuanlong Ni ◽  
...  

The experimental progress of laser equation of state (EOS) studies at Shanghai Institute of Laser Plasma (SILP) is discussed in this paper. With a unique focal system, the uniformity of the laser illumination on the target surface is improved and a laser-driven shock wave with good spatial planarity is obtained. With an inclined aluminum target plane, the stability of shock waves are studied, and the corresponding thickness range of the target of laser-driven shock waves propagating steadily are given. The shock adiabats of Cu, Fe, SiO2 are experimentally measured. The pressure in the material is heightened remarkably with the flyer increasing pressure, and the effect of the increasing pressure is observed. Also, the high-pressure shock wave is produced and recorded in the experimentation of indirect laser-driven shock waves with the hohlraum target.


2004 ◽  
Vol 42 (6) ◽  
pp. 911-918 ◽  
Author(s):  
T. V. Bazhenova ◽  
V. V. Golub ◽  
A. L. Kotel?nikov ◽  
A. S. Chizhikov ◽  
M. V. Bragin ◽  
...  

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Konstantin I. Matveev ◽  
Sungmin Jung

The subject of this paper is modeling of low-amplitude acoustic fields in enclosures with nonuniform medium and boundary conditions. An efficient calculation method is developed for this class of problems. Boundary conditions, accounting for the boundary-layer losses and movable walls, are applied near solid surfaces. The lossless acoustic wave equation for a nonuniform medium is solved in the bulk of the resonator by a finite-difference method. One application of this model is for designing small thermoacoustic engines. Thermoacoustic processes in the regular-geometry porous medium inserted in resonators can be modeled analytically. A calculation example is presented for a small-scale thermoacoustic engine coupled with an oscillator on a flexing wall of the resonator. The oscillator can be used for extracting mechanical power from the engine. A nonuniform wall deflection may result in a complicated acoustic field in the resonator. This leads to across-the-stack variations of the generated acoustic power and local efficiency of thermoacoustic energy conversion.


2011 ◽  
Vol 1 (32) ◽  
pp. 67
Author(s):  
Boyang Jiang ◽  
James Kaihatu

As the forecasting models become more sophisticated in their physics and possible depictions of the nearshore hydrodynamics, they also become increasingly sensitive to errors in the inputs, such as errors in the specification of boundary information (lateral boundary conditions, initial boundary conditions, etc). Evaluation of the errors on the boundary is less straightforward, and is the subject of this study. The model under investigation herein is the Delft3D modeling suite, developed at Deltares (formerly Delft Hydraulics) in Delft, the Netherlands. Coupling of the wave (SWAN) and hydrodynamic (FLOW) model requires care at the lateral boundaries in order to balance run time and error growth. To this extent, we will use perturbation method and spatio-temporal analysis method such as Empirical Orthogonal Function (EOF) analysis to determine the various scales of motion in the flow field and the extent of their response to imposed boundary errors.


2021 ◽  
Vol 2088 (1) ◽  
pp. 012027
Author(s):  
A V Kapustin ◽  
V I Melikhov ◽  
O I Melikhov ◽  
B Saleh ◽  
D V Finoshkina

Abstract It was developed the model of thermal detonation in a mixture of continuous liquid lead and dispersed steam/water particles. Stationary equations of mass, impulse and energy conservations laws for multiphase continuum are applied to describe internal structure of thermal detonation wave. They are supplemented by closing relations describing interfacial friction, heat transfer, and fragmentation. Conditions at leading shock wave and at Chapman-Jouguet plane are used as boundary conditions.


1993 ◽  
Vol 14 (12) ◽  
pp. 1151-1162
Author(s):  
Xu Fu ◽  
Chen Le-shan

2014 ◽  
Vol 566 ◽  
pp. 344-349
Author(s):  
M. Nabil Bassim ◽  
S. Boakye-Yiadom ◽  
Manon Bolduc

A set of 18 armour steel plates were stacked on top of each other and subjected to shape charges that went through the plates and created a hole that decreased in diameter as it went through consecutive plates. Afterwards, the plates were examined and the hardness near the hole and away from the hole was taken to determine the effect of the passing of the shaped charge through the plates. Also, specimens from the walls of the holes were taken to determine changes in the microstructure due to the shock wave and the resulting excessive heating from the shape charge. It was observed that the shock wave produced significant changes in the microstructure resulting in the appearance adiabatic shear bands (ASBs). These ASBs persisted in holes in plates placed further down the stack (up to 8thin the stack). More complex microstructural mechanisms are thought to take place as opposed to erosion from the flow of the molten metal through the holes in the plates.


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