A Study of Fluid Argon via the Constant Volume Specific Heat, the Isothermal Compressibility, and the Speed of Sound and their Extremum Properties along Isotherms

1975 ◽  
Vol 53 (14) ◽  
pp. 1367-1384 ◽  
Author(s):  
John Stephenson
Keyword(s):  
Equation Of State ◽  
Specific Heat ◽  
Speed Of Sound ◽  
Isothermal Compressibility ◽  
Constant Volume ◽  
Liquid Region ◽  
Fluid Argon ◽  
Unified Description ◽  
Dense Liquid ◽  
Sound Data

The properties of fluid argon are investigated via the maxima and minima along isotherms of selected thermodynamic functions, the isothermal compressibility, χT, the constant volume specific heat, CV, and the speed of sound, W. Calculations are based on an equation of state due to Gosman, McCarty, and Hust and on speed of sound data compiled by Thoen, Vangeel, and Van Dael. The calculation of CV in the dense liquid region, from the equation of state and from the speed of sound, is discussed in detail. Also, the linear dependence of W on the density in the liquid region is reconciled with the behaviour of W at temperatures above critical to obtain a unified description of the variation of W along isotherms.

scholarly journals The Thermal Expansion of Solids

1959 ◽  
Vol 12 (3) ◽  
pp. 237 ◽  
Author(s):  
GC Fletcher
Keyword(s):  
Thermal Expansion ◽  
Sodium Chloride ◽  
Equation Of State ◽  
Specific Heat ◽  
High Temperatures ◽  
Isothermal Compressibility ◽  
Constant Volume ◽  
Normal Vibrations ◽  
Ionic Solid ◽  
Theory And Experiment

From the theory of normal vibrations of a lattice, a practical means of obtaining the equation of state of an ionic solid is developed from which the thermal expansion can be derived. Using previous work by Kellermann, application is made to the case of sodium chloride and the results compared with experiment. Possible reasons for the discrepancy between theory and experiment, which is very large at 'high temperatures, are discussed. The variation with temperature of the specific heat at constant volume and the isothermal compressibility are also investigated.

Loci of maxima and minima of thermodynamic functions of a simple fluid

1976 ◽  
Vol 54 (12) ◽  
pp. 1282-1291 ◽  
Author(s):  
John Stephenson
Keyword(s):  
Specific Heat ◽  
Thermodynamic Functions ◽  
Speed Of Sound ◽  
Isothermal Compressibility ◽  
Constant Pressure ◽  
Van Der Waals ◽  
Experimental Results ◽  
Van Der Waals Equation ◽  
Simple Fluid ◽  
Fluid Argon

Some elementary properties of loci of extrema of thermodynamic functions are established and discussed in connection with maxima and minima of the constant volume specific heat, CV, the isothermal compressibility, χT, and the constant pressure specific heat, CP, along isotherms, and the extremum properties of the isobaric coefficient of expansion, αP, along isobars. Experimental results for fluid argon are used to construct the required loci of extrema. Van der Waals' equation is applied to obtain loci of extrema for χT, CP, and αP, for the speed of sound W, and for related inflexion loci.

Equation of State andP−V−T−xProperties of Refrigerant Mixtures Based on Speed of Sound Data

2003 ◽  
Vol 42 (16) ◽  
pp. 3802-3808 ◽  
Author(s):  
Mohammad Mehdi Papari ◽  
Ahmad Razavizadeh ◽  
Fathollah Mokhberi ◽  
Ali Boushehri
Keyword(s):  
Equation Of State ◽  
Speed Of Sound ◽  
Refrigerant Mixtures ◽  
Sound Data

FALSIFICATIONS OF POISSON ADIABATE, HUGONIO ADIABATE, LAPLACE SOUND SPEEDS. MODERNIZATION OF FOUNDATIONS OF THERMODYNAMICS

2020 ◽  
Vol 5 (333) ◽  
pp. 58-67
Author(s):  
K.B. Jakupov ◽  
Keyword(s):  
Shock Wave ◽  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Speed Of Sound ◽  
Constant Pressure ◽  
Energy Balance Equation ◽  
Ideal Gas ◽  
Constant Volume ◽  
Capacity Coefficient

The inequality of the universal gas constant of the difference in the heat capacity of a gas at constant pressure with the heat capacity of a gas at a constant volume is proved. The falsifications of using the heat capacity of a gas at constant pressure, false enthalpy, Poisson adiabat, Laplace sound speed, Hugoniot adiabat, based on the use of the false equality of the universal gas constant difference in the heat capacity of a gas at constant pressure with the heat capacity of a gas at a constant volume, have been established. The dependence of pressure on temperature in an adiabatic gas with heat capacity at constant volume has been established. On the basis of the heat capacity of a gas at a constant volume, new formulas are derived: the adiabats of an ideal gas, the speed of sound, and the adiabats on a shock wave. The variability of pressure in the field of gravity is proved and it is indicated that the use of the specific coefficient of ideal gas at constant pressure in gas-dynamic formulas is pointless. It is shown that the false “basic formula of thermodynamics” implies the falseness of the equation with the specific heat capacity at constant pressure. New formulas are given for the adiabat of an ideal gas, adiabat on a shock wave, and the speed of sound, which, in principle, do not contain the coefficient of the specific heat capacity of a gas at constant pressure. It is shown that the well-known equation of heat conductivity with the gas heat capacity coefficient at constant pressure contradicts the basic energy balance equation with the gas heat capacity coefficient at constant volume.

scholarly journals Hadronic equation of state and speed of sound in thermal and dense medium

2014 ◽  
Vol 29 (27) ◽  
pp. 1450152 ◽  
Author(s):  
Abdel Nasser Tawfik ◽  
Hend Magdy
Keyword(s):  
Equation Of State ◽  
Specific Heat ◽  
High Temperatures ◽  
Speed Of Sound ◽  
Chemical Potential ◽  
Dense Medium ◽  
Thermodynamic Quantities ◽  
Strange Hadron ◽  
The Difference ◽  
Grand Canonical

The equation of state p(ϵ) and speed of sound squared [Formula: see text] are studied in grand canonical ensemble of all hadron resonances having masses ≤2 GeV . This large ensemble is divided into strange and non-strange hadron resonances and furthermore to pionic, bosonic and fermionic sectors. It is found that the pions represent the main contributors to [Formula: see text] and other thermodynamic quantities including the equation of state p(ϵ) at low temperatures. At high temperatures, the main contributions are added in by the massive hadron resonances. The speed of sound squared can be calculated from the derivative of pressure with respect to the energy density, ∂p/∂ϵ, or from the entropy-specific heat ratio, s/cv. It is concluded that the physics of these two expressions is not necessarily identical. They are distinguishable below and above the critical temperature Tc. This behavior is observed at vanishing and finite chemical potential. At high temperatures, both expressions get very close to each other and both of them approach the asymptotic value, 1/3. In the hadron resonance gas (HRG) results, which are only valid below Tc, the difference decreases with increasing the temperature and almost vanishes near Tc. It is concluded that the HRG model can very well reproduce the results of the lattice quantum chromodynamics (QCD) of ∂p/∂ϵ and s/cv, especially at finite chemical potential. In light of this, energy fluctuations and other collective phenomena associated with the specific heat might be present in the HRG model. At fixed temperatures, it is found that [Formula: see text] is not sensitive to the chemical potential.

scholarly journals (P,ρ,T) properties of 1-octyl-3-methylimidazolium tetrafluoroborate

2018 ◽  
Vol 83 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Javid Safarov ◽  
Aygul Namazova ◽  
Astan Shahverdiyev ◽  
Egon Hassel
Keyword(s):  
Equation Of State ◽  
Speed Of Sound ◽  
Isothermal Compressibility ◽  
Constant Pressure ◽  
Pressure Coefficient ◽  
Heat Capacities ◽  
Thermal Pressure ◽  
Average Percent Deviation ◽  
Wide Range ◽  
Isentropic Exponent

(p,?,T) data of 1-octyl-3-methylimidazolium tetrafluoroborate [OMIM][BF4] over a wide range of temperatures, from 278.15 to 413.15 K, and pressures, p, up to 140 MPa are reported with an estimated ?0.01?0.08 % experimental relative average percent deviation (APD) in the density. The measurements were performed using an Anton Paar DMA HPM vibration tube densimeter. (p,?,T) Data for [OMIM][BF4] was fitted and the parameters of the applied equation were determined as a function of pressure and temperature. After a thorough analysis of literature values and validity of the used equation of state, various thermophysical properties, such as isothermal compressibility, isobaric thermal expansibility, differences in isobaric and isochoric heat capacities, thermal pressure coefficient, internal pressure, heat capacities at constant pressure and volume, speed of sound and isentropic exponent at temperatures in the range 278.15?413.15 K and pressures p up to 140 MPa were calculated.

scholarly journals Speed of sound and quark confinement inside neutron stars

2020 ◽  
Vol 229 (22-23) ◽  
pp. 3651-3661
Author(s):  
Michał Marczenko
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Speed Of Sound ◽  
Dense Matter ◽  
High Mass ◽  
Quark Confinement ◽  
Binary Neutron Star ◽  
Upper Limit ◽  
Unified Description

AbstractSeveral observations of high-mass neutron stars (NSs), as well as the first historic detection of the binary neutron star merger GW170817, have delivered stringent constraints on the equation of state (EoS) of cold and dense matter. Recent studies suggest that, in order to simultaneously accommodate a 2M⊙ NS and the upper limit on the compactness, the pressure has to swiftly increase with density and the corresponding speed of sound likely exceeds the conformal limit. In this work, we employ a unified description of hadron-quark matter, the hybrid quark-meson-nucleon (QMN) model, to investigate the EoS under NS conditions. We show that the dynamical confining mechanism of the model plays an important role in explaining the observed properties of NSs.

scholarly journals On the approximation of isochoric motions of fluids under different flow conditions

2015 ◽  
Vol 471 (2180) ◽  
pp. 20150159 ◽  
Author(s):  
K. R. Rajagopal ◽  
G. Saccomandi ◽  
L. Vergori
Keyword(s):  
Specific Heat ◽  
Volume Change ◽  
Speed Of Sound ◽  
Deformation Gradient ◽  
Boussinesq Approximation ◽  
Constant Volume ◽  
The Body ◽  
Flow Conditions

There has been considerable interest, ever since the development of the approximation by Oberbeck and Boussinesq concerning fluids that are mechanically incompressible but thermally compressible, in giving a rigorous justification for the same. For such fluids, it would be natural to assume that the determinant of the deformation gradient (which is a measure of the volume change of the body) depends on the temperature. However, such an assumption has the attendant drawbacks of the specific heat of the fluid at constant volume being zero and the speed of sound in the fluid being complex. In this paper, we consider a generalization of the Oberbeck–Boussinesq approximation, wherein the volume change depends both on the temperature and on the pressure that the fluid is subject to. We show that within the context of this generalization, the specific heat at constant volume can be defined meaningfully, and it is not zero.

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