Some Properties of Compressional Waves in Lennard-Jones and Devonshire Liquids. II. Shock Waves

1961 ◽  
Vol 14 (3) ◽  
pp. 372 ◽  
Author(s):  
HG David ◽  
SD Hamann
Keyword(s):  
Shock Wave ◽  
Equation Of State ◽  
Shock Waves ◽  
Qualitative Agreement ◽  
Theoretical Calculations ◽  
Condensed Substance ◽  
Adiabatic Expansion ◽  
Good Qualitative Agreement ◽  
Compressional Waves ◽  
Lennard Jones

This paper describes some theoretical calculations of the thermodynamic changes which occur when a condensed substance is compressed by a shock wave from an explosion. It is assumed that the material is a simple molecular fluid (or a plastic solid) obeying Lennard-Jones and Devonshire's equation of state. The calculations have been applied to single and colliding shock waves, to shocks generated in a precompressed material, and to the adiabatic expansion of a material from a shocked state. The results are in good qualitative agreement with the experi- mental data where these exist. In addition they suggest possible ways of extending the scope and usefulness of shock wave experiments.

scholarly journals Equation of state studies at SILP by laser-driven shock waves

1996 ◽  
Vol 14 (2) ◽  
pp. 157-169 ◽  
Author(s):  
Yuan Gu ◽  
Sizu Fu ◽  
Jiang Wu ◽  
Songyu Yu ◽  
Yuanlong Ni ◽  
...  
Keyword(s):  
Shock Wave ◽  
High Pressure ◽  
Equation Of State ◽  
Shock Waves ◽  
Target Surface ◽  
Shock Adiabats ◽  
Pressure Shock ◽  
Aluminum Target ◽  
Laser Illumination ◽  
The Stability

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.

BULK NANOSTRUCTURED MATERIALS OBTAINED BY SHOCK WAVES COMPACTION OF ULTRAFINE TITANIUM AND ALUMINUM

2012 ◽  
Vol 05 ◽  
pp. 391-399
Author(s):  
NIKOLOZ M. CHIKHRADZE ◽  
CONSTANTIN POLITIS ◽  
MIKHEIL CHIKHRADZE ◽  
GEORGE ONIASHVILI
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Theoretical Calculations ◽  
Steel Tube ◽  
Hydrodynamic Theory ◽  
Full Density ◽  
Experimental Investigations ◽  
Disperse Powder ◽  
Explosive Compaction ◽  
Structural Investigations

Theoretical and experimental Investigations of shock wave consolidation processes of Ti - Al nano sized and ultra-disperse powder compositions are discussed. For theoretical calculations of the shock wave loaded materials were used the hydrodynamic theory and experimental adiabatic of Ti and Al . The normal and tangential stresses in the cylindrical steel tube (containers of Ti - Al reaction mixtures) were estimated using the partial solutions of elasticity theory. The mixtures of ultra-disperse Ti and nano sized (≤ 50nm) Al powder compositions were consolidated to full or near-full density by explosive-compaction technology. The ammonium nitride based industrial explosives were used for generation of shock waves. To form ultra-fine grained bulk TiAl intermetallics with different compositions, ultra-disperse Ti particles were mixed with nano-crystalline Al . Each reaction mixture was placed in a sealed container and explosively compacted using a normal and cylindrical detonation set-up. Explosive compaction experiments were performed in range of pressure impulse (5-20) GPa. X-ray diffraction (XRD), structural investigations (SEM) and micro-hardness measurements were used to characterize the intermetallics phase composition and mechanical properties. The results of analysis revealing the effects of the compacting conditions and precursor particles sizes, affecting the consolidation and the properties of this new ultra high performance alloys are discussed.

scholarly journals Multi-phase equation of state for aluminum

2007 ◽  
Vol 25 (4) ◽  
pp. 567-584 ◽  
Author(s):  
I.V. Lomonosov
Keyword(s):  
Shock Wave ◽  
Phase Diagram ◽  
High Pressure ◽  
Equation Of State ◽  
Thermodynamic Properties ◽  
Critical Point ◽  
Theoretical Calculations ◽  
Static Compression ◽  
Multi Phase ◽  
Solid Liquid

AbstractResults of theoretical calculations and experimental measurements of the equation of state (EOS) at extreme conditions are discussed and applied to aluminum. It is pointed out that the available high pressure and temperature information covers a broad range of the phase diagram, but only irregularly and, as a rule, is not thermodynamically complete; its generalization can be done only in the form of a thermodynamically complete EOS. A multi-phase EOS model is presented, accounting for solid, liquid, gas, and plasma states, as well as two-phase regions of melting and evaporation. The thermodynamic properties of aluminum and its phase diagram are calculated with the use of this model. Theoretical calculations of thermodynamic properties of the solid, liquid, and plasma phases, and of the critical point, are compared with results of static and dynamic experiments. The analysis deals with thermodynamic properties of solid aluminum at T = 0 and 298 K from different band-structure theories, static compression experiments in diamond anvil cells, and the information obtained in isentropic-compression and shock-wave experiments. Thermodynamic data in the liquid state, resulting from traditional thermophysical measurements, “exploding wire” experiments, and evaluations of the critical point are presented. Numerous shock-wave experiments for aluminum have been done to measure shock adiabats of crystal and porous samples, release isentropes, and sound speed in shocked metal. These data are analyzed in a self-consistent manner together with all other available data at high pressure.The model's results are shown for the principal shock adiabat, the high-pressure melting and evaporation regions and the critical point of aluminum. New experimental and theoretical data helped to improve the description of the high-pressure, high-temperature aluminum liquid. The present EOS describes with high accuracy and reliability the complete set of available information.

ELECTRICAL CONDUCTIVITY OF INERT GASES—SEED COMBINATION IN SHOCK TUBES

1964 ◽  
Vol 42 (8) ◽  
pp. 1548-1563 ◽  
Author(s):  
J. Lau
Keyword(s):  
Shock Wave ◽  
Electrical Conductivity ◽  
Shock Waves ◽  
Alkali Metal ◽  
Shock Tube ◽  
Digital Computer ◽  
Theoretical Calculations ◽  
Inert Gases ◽  
Temperature Ratio ◽  
Seeding Material

The effect of seeding shock waves with alkali metal smoke is studied. The pressure, density, temperature ratio, electron density, and conductivity were calculated with a digital computer and tabulated for various combinations of gas and seeding material. A hydrogen-driven shock tube was constructed to measure the properties of the seeded gas behind the shock wave. The conductivity of argon seeded with cesium was measured with a conductivity probe and compared with theoretical calculations.

A Theoretical Investigation of Pressure Depression in Externally Pressurized Gas-Lubricated Circular Thrust Bearings

1961 ◽  
Vol 83 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Haruo Mori
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Shock Wave ◽  
Qualitative Agreement ◽  
Load Capacity ◽  
Pressure Profile ◽  
Theoretical Explanation ◽  
Good Qualitative Agreement ◽  
Thrust Bearings ◽  
Approximate Mathematical Model

A theoretical explanation of the experimentally observed depression of the pressure profile in externally pressurized gas-lubricated circular thrust bearings is presented, based on a concept new to gas lubrication, that of the generation of a shock wave in the bearing clearance space. On the basis of an approximate mathematical model, the bearing pressure distribution and load capacity are determined, and the effects of several bearing parameters are discussed. Good qualitative agreement is found between the analytical results and available experimental data.

Investigation of shock-wave deformation history from recovered structure

1986 ◽  
Vol 44 ◽  
pp. 434-435
Author(s):  
M.A. Mogilevsky ◽  
L.S. Bushnev
Keyword(s):  
Shock Wave ◽  
Plastic Deformation ◽  
Dislocation Density ◽  
Shock Waves ◽  
Shock Front ◽  
Single Crystals ◽  
Residual Deformation ◽  
Deformation Structure ◽  
Deformation History ◽  
Deformation Velocity

Single crystals of Al were loaded by 15 to 40 GPa shock waves at 77 K with a pulse duration of 1.0 to 0.5 μs and a residual deformation of ∼1%. The analysis of deformation structure peculiarities allows the deformation history to be re-established.After a 20 to 40 GPa loading the dislocation density in the recovered samples was about 1010 cm-2. By measuring the thickness of the 40 GPa shock front in Al, a plastic deformation velocity of 1.07 x 108 s-1 is obtained, from where the moving dislocation density at the front is 7 x 1010 cm-2. A very small part of dislocations moves during the whole time of compression, i.e. a total dislocation density at the front must be in excess of this value by one or two orders. Consequently, due to extremely high stresses, at the front there exists a very unstable structure which is rearranged later with a noticeable decrease in dislocation density.

Features of spatial shock-wave flows in vapor-gas-liquid mixtures

2014 ◽  
Vol 10 ◽  
pp. 27-31
Author(s):  
R.Kh. Bolotnova ◽  
U.O. Agisheva ◽  
V.A. Buzina
Keyword(s):  
Shock Wave ◽  
High Pressure ◽  
Shock Waves ◽  
Liquid Mixture ◽  
Liquid Mixtures ◽  
Pressure Vessels ◽  
Water Mixture ◽  
Two Dimensional ◽  
Nonstationary Processes ◽  
Two Phase

The two-phase model of vapor-gas-liquid medium in axisymmetric two-dimensional formulation, taking into account vaporization is constructed. The nonstationary processes of boiling vapor-water mixture outflow from high-pressure vessels as a result of depressurization are studied. The problems of shock waves action on filled by gas-liquid mixture volumes are solved.

Equation of state of a Lennard-Jones 12-6 pairwise additive fluid

1980 ◽  
Vol 45 (4) ◽  
pp. 977-983 ◽  
Author(s):  
Jan Sýs ◽  
Anatol Malijevský
Keyword(s):  
Equation Of State ◽  
Empirical Equation ◽  
The State ◽  
Critical Properties ◽  
Lennard Jones ◽  
State Behaviour ◽  
Compressibility Factors

An empirical equation of state was proposed, which is based on pseudoexperimental data on the state behaviour. The equation can be used at reduced temperatures from the range 0.7-100.0 and reduced densities up to 2. Calculated compressibility factors and critical properties agree well with available literature data.

scholarly journals Nematic Dispersive Shock Waves from Nonlocal to Local

2021 ◽  
Vol 11 (11) ◽  
pp. 4736
Author(s):  
Saleh Baqer ◽  
Dimitrios J. Frantzeskakis ◽  
Theodoros P. Horikis ◽  
Côme Houdeville ◽  
Timothy R. Marchant ◽  
...  
Keyword(s):  
Shock Wave ◽  
Liquid Crystals ◽  
Shock Waves ◽  
Numerical Solutions ◽  
Wave Structure ◽  
Beam Power ◽  
Input Beam ◽  
Shock Wave Structure ◽  
Wave Solutions ◽  
Modulation Theory

The structure of optical dispersive shock waves in nematic liquid crystals is investigated as the power of the optical beam is varied, with six regimes identified, which complements previous work pertinent to low power beams only. It is found that the dispersive shock wave structure depends critically on the input beam power. In addition, it is known that nematic dispersive shock waves are resonant and the structure of this resonance is also critically dependent on the beam power. Whitham modulation theory is used to find solutions for the six regimes with the existence intervals for each identified. These dispersive shock wave solutions are compared with full numerical solutions of the nematic equations, and excellent agreement is found.

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