Showing papers by "Joseph Kestin published in 1976"
TL;DR: In this article, the authors present a complete, modernized theory of the transient hot-wire method for measuring the thermal conductivity of fluids which can be employed in the form of an absolute instrument and can be operated with a precision of 0.02% and an accuracy of 2.2%.
Abstract: The paper contains a complete, modernized theory of the transient hot-wire method for measuring the thermal conductivity of fluids which can be employed in the form of an absolute instrument and which can be operated with a precision of 0.02% and an accuracy of 0.2%. It is a companion paper for ref. 1.
The analysis demonstrates that the instrument can be designed to imitate very closely the behaviour of a finite portion of an infinite line source of constant heat flux, q, which transfers the heat radially into an infinite fluid.
Expressions for the corrections are obtained by a general perturbation method which allows us to examine them one or several at a time. The principal corrections discussed in the form of nine subproblems are: finite inner cylinder, composite cylinders, Knudsen effects, radiation, outer cell circumference, compressibility and natural convection, finite cell dimensions, variable fluid properties and heating over a finite length.
The last section summarizes the most important corrections for a reader who is interested in using them rather than in following the analysis itself. The main text supplies all data required by the designer of an instrument of this type.
390 citations
TL;DR: In this paper, the authors used the kinetic theory expressions for multicomponent gas mixtures and the law of corresponding states and the appropriate binary scaling parameters σij and eij to generate the viscosities of several ternary and quaternary mixtures of these gases.
Abstract: In a series of earlier papers it has been established that the viscosities of the pure gases CH4, CO2, CF4, and SF6 as well as those of their binary mixtures conform to the extended law of corresponding states formulated by Kestin, Ro, and Wakeham. In this paper, the kinetic‐theory expressions for multicomponent gas mixtures are used in conjunction with the law of corresponding states and the appropriate binary scaling parameters σij and eij to generate the viscosities of several ternary and quaternary mixtures of these gases. The calculated viscosities are compared with direct measurements (accuracy ±0.2%) performed in an oscillating disk instrument in the temperature range 25–200°C. The comparison reveals that the generated data depart from the measured viscosities by a maximum of 0.5% and that the standard deviation is only 0.25% which is comparable with the experimental uncertainty. The validity of the calculation scheme presented for predictive purposes is thereby confirmed. It is emphasized that the...
28 citations
01 Jul 1976
TL;DR: In this article, the authors analyzed earlier data on the viscosity of binary and ternary mixtures in terms of the extended law of corresponding states due to Kestin, Ro and Wakeham (KRW).
Abstract: The paper analyses earlier data on the viscosity of binary and ternary mixtures in terms of the extended law of corresponding states due to Kestin, Ro, and Wakeham (KRW). The binary mixtures involve CO2 and CH4 with each other, and each with He, Ne, Ar, N2. The ternary mixtures are: N2ArCO2 and CH4N2CO2.
Measurements fully corroborate the efficiency of the KRW law for the calculation of viscosity and binary diffusion coefficient of the simpler polyatomic gases, as expected from theory.
The paper contains short tables of the viscosity and binary diffusion coefficients for the nine binary systems under consideration.
Der Aufsatz enthalt eine Besprechung fruherer Messungen der Viskositat von binaren und ternaren Gemischen im Lichte des erweiterten Gesetzes der ubereinstimmenden Zustande von Kestin, Ro und Wakeham (KRW). Die binaren Gemische bestehen aus CO2 und CH4 unter-einander und auch mit He, Ne, Ar, N2. Die ternaren Gemische sind: N2ArCO2 und CH4N2CO2.
Die Messungen bestatigen die Leistungsfahigkeit des KRW-Gesetzes fur die Berechnung der Viskositat und des Diffusionskoeffizienten von einfacheren polyatomaren Gasen, wie es aus der Theorie zu erwarten ist.
Der Aufsatz enthalt kurze Tabellen der Viskositat und des Diffusionskoeffizienten der neun betreffenden binaren Systeme.
22 citations
TL;DR: In this paper, an arrangement which can be used to measure the period and logarithmic decrement of a damped harmonic torsional oscillation without the need to perform any length measurements is described.
Abstract: The paper describes an arrangement which can be used to measure the period and logarithmic decrement of a damped harmonic torsional oscillation without the need to perform any length measurements. By means of suitably arranged electronic circuits, all measurements are reduced to those of time intervals. These consist of a measurement of the period and of two time intervals which a travelling laser beam requires to sweep past two stationary photoresistances. A suitable procedure for the location of a zero base line is indicated, and it is shown that the residual uncertainty of this operation is the source of the dominant error.
15 citations
01 Jan 1976
TL;DR: In this paper, a method based on the modified Enskog theory (MET) as extended to binary mixtures by H.H. Thorne is presented which allows the computation of the thermal conductivity of binary mixture of monatomic gases up to densities of about 200 amagat with an uncertainty no greater than 2 percent when compared with the best available measurements.
Abstract: A method, based on the modified Enskog theory (MET), as extended to binary mixtures by H.H. Thorne, is presented which allows the computation of the thermal conductivity of binary mixtures of monatomic gases up to densities of about 200 amagat with an uncertainty no greater than 2 percent when compared with the best available measurements.