A volume equation of state that extends thermodynamic datasets, using the Bridgman Power Series, to very high pressures (20 GPa)

2016 ◽  
Vol 316 (6) ◽  
pp. 578-589 ◽  
Author(s):  
E. Duesterhoeft
Keyword(s):  
Equation Of State ◽  
Power Series ◽  
High Pressures ◽  
Volume Equation ◽  
Very High

On the collapse of an empty cavity in water

1960 ◽  
Vol 8 (2) ◽  
pp. 241-263 ◽  
Author(s):  
C. Hunter
Keyword(s):  
Equation Of State ◽  
Similarity Solution ◽  
High Pressures ◽  
Similarity Theory ◽  
Flow Equations ◽  
Regularity Properties ◽  
Flow Speeds ◽  
Empty Cavity ◽  
Subsequent Propagation ◽  
Very High

This paper is concerned with the spherically symmetric collapse of an empty cavity in water. The effects of viscosity and surface tension are neglected, but the compressibility of the water is allowed for and a suitable equation of state for the water assumed. The object of this is to clarify the effect of compressibility on the flow by considering it in isolation and thus to describe the formation of a pressure pulse by the collapse and its subsequent propagation.The exact flow equations are integrated numerically and it is found that very high flow speeds develop in the neighbourhood of the collapse point. The radius of the cavity is found to be proportional to (-t)nfor smallt, wheret= 0 is the instant of collapse, andnis some positive number less than unity.The flow in the neighbourhood of the collapse point can be described by means of a similarity solution, and the value ofnis determined by regularity properties of the similarity solution (the value ofndepends on the equation of state assumed for the water). The similarity theory, which is valid only at very high pressures and velocities, can be continued beyond the instant of collapse to describe the formation of a shock wave after the collapse is completed, and the initial propagation of this shock.

An Experimental Study on the Equation of State of Cementitious Materials Using Confined Compression Tests

2016 ◽  
Vol 711 ◽  
pp. 830-836 ◽  
Author(s):  
Yuri S. Karinski ◽  
Semion Zhutovsky ◽  
Vladimir R. Feldgun ◽  
David Z. Yankelevsky
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
High Pressure ◽  
Equation Of State ◽  
High Pressures ◽  
Uniaxial Loading ◽  
Ductile Material ◽  
Compression Tests ◽  
Confined Compression ◽  
Very High

The behavior of concrete under severe loading is of interest, especially for problems like ballistic impact and penetration and near distance explosions, where very high pressures are developed. For these problems the behavior of concrete at very high hydrostatic pressures is of importance. There is very little data available on concrete behavior at that high pressure level. Therefore there is much need for an extensive experimental work in order to provide necessary data and illuminate the rather obscure area of concrete behavior at high pressures. However high pressure controlled testing requires special and expensive equipment, and the testing is associated with a wide variety of technical problems. Recently published experimental data, obtained by utilizing a high-capacity tri-axial press, indicates that concrete that is subjected to high pressures behaves differently than concrete under low uniaxial loading. When uniaxial loading is applied, without any confining pressure, the concrete specimen demonstrates a well-known brittle behavior where failure is caused by a localized damage. Quite to the contrary, at high levels of confining pressures, the concrete behaves like a ductile material, and its failure is associated with diffuse material damage. The experimental data at the very high pressure range is most important to understand the processes of damage evolution that governs the characteristics of the equation of state. This paper presents the development of an experimental setup that is capable of performing confined compression tests of mortar and concrete specimens at high pressures up to 400MPa. The experimental study aims at investigating the effect of water/cement ratio as well as the ratio of fine aggregate on the different branches of the equation of state: active loading and unloading/reloading. The paper presents some of the test results as well as a new equation of state that is based on the multi scale approach. The model is applicable for dry materials; cementitious paste and concrete in which the pores are filled with water should be treated differently to account for the liquid phase.

scholarly journals Gaseous combustion at high pressures. —Part X. The co-volume corrections, maximum temperatures and dissociation of steam and carbon dioxide in explosions

1928 ◽  
Vol 119 (782) ◽  
pp. 464-480
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Internal Energy ◽  
High Temperatures ◽  
High Pressures ◽  
Internal Combustion ◽  
Systematic Survey ◽  
Explosion Method ◽  
Maximum Temperatures ◽  
Very High

During the researches upon high-pressure explosions of carbonic oxide-air, hydrogen-air, etc., mixtures, which have been described in the previous papers of this series, a mass of data has been accumulated relating to the influence of density and temperature upon the internal energy of gases and the dissociation of steam and carbon dioxide. Some time ago, at Prof. Bone’s request, the author undertook a systematic survey of the data in question, and the present paper summarises some of the principal results thereof, which it is hoped will throw light upon problems interesting alike to chemists, physicists and internal-combustion engineers. The explosion method affords the only means known at present of determining the internal energies of gases at very high temperatures, and it has been used for this purpose for upwards of 50 years. Although by no means without difficulties, arising from uncertainties of some of the assumptions upon which it is based, yet, for want of a better, its results have been generally accepted as being at least provisionally valuable. Amongst the more recent investigations which have attracted attention in this connection should be mentioned those of Pier, Bjerrum, Siegel and Fenning, all of whom worked at low or medium pressures.

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