58 research outputs found
Reference Correlation for the Density and Viscosity of Eutectic Liquid Alloys Al+Si, Pb+Bi, and Pb+Sn
In this paper, the available experimental data for the density and viscosity of eutectic liquid alloys Al+Si, Pb+Bi, and Pb+Sn have been critically examined with the intention of establishing a reference standard representation of both, density and viscosity. All experimental data have been categorized as primary or secondary according to the quality of measurement, the technique employed, and the presentation of the data, as specified by a series of carefully defined criteria. The proposal standard reference correlations for the density of liquid Al+Si, Pb+Si, and Pb+Sn are, repectively, characterized by deviations of 2.0%, 2.9%, and 0.5% at the 95% confidence level. The standard reference correlations for the viscosity of liquid Al+Si, Pb+Bi, and Pb+Sn are, repectively, characterized by deviations of 7.7%, 14.2%, and 12.4% at the 95% confidence level
Molten metals: a challenge for measurement
The transport properties of fluids are, arguably, more sensitive probes of the forces between molecular species than are the equilibrium thermodynamic properties. The same properties are of engineering significance because they determine the size of process plant while equilibrium properties often determine feasibility. However, the measurement of the transport properties with an accuracy, which has enabled advantage of this circumstance to be taken, has proved rather more difficult and the industrial need for properties alone has seldom justified the effort. Lessons that have been learned about the measurement of the transport properties of simple fluids such as the monatomic gases and organic liquids have now provided the experience upon which to base measurements on less traditional materials under harsher conditions.The present paper reviews some of these historical lessons and shows how they have been applied to just one example from among current activities. The example concerns the measurement of the thermal conductivity of molten metals in a manner which can be validated at moderate temperatures and subsequently applied to more aggressive conditions
Thermal conductivity of liquid tin and indium
The present paper reports new measurements of the thermal conductivity of liquid tin and indium. The measurements have been performed at atmospheric pressure in a range of temperatures from 450 to 750 K using a new experimental method based on the principle of the transient hot wire technique. The particular version of the technique employed for molten metals has been shown to have an accuracy in the measurement of the thermal conductivity of molten metals of ±2%. Ultimately, it is intended that the technique operate in a wide range of temperatures, from ambient up to 1200 K, and work is in progress to increase the working temperature and to extend the range of measurements. The results are compared with experimental data reported in the literature by other authors and with predictions of the Wiedemann and Franz law
Thermal conductivity of oct-1-ene in the temperature range 307 to 360 K at pressures up to 0.5 GPa
10.1007/BF00567101International Journal of Thermophysics84407-414IJTH
Prediction of the viscosity of liquid mixtures
This paper describes the application of the theoretically based scheme of Vesovic and Wakeham, modified by making use of the hard-sphere model of Dymond and Assael, to the prediction of the viscosity of liquid mixtures. The purpose of the paper is to examine this scheme in more detail than earlier to find out in what circumstances it works well and when it fails. Hence, the scheme is employed to predict, for the first time, the viscosity of a wide range of mixtures of quite disparate liquids from groups of hydrocarbons, through combinations of alcohols and hydrocarbons, to halogenated refrigerants. It is shown that, in all cases, provided that the mass ratio of the pure components is close to unity, the predictions show excellent agreement with experiment
Thermal conductivity of molten lead-free solders
The paper reports measurements of the thermal conductivity of a number of
molten solders for the electronics industry that are part of a group of materials
designed to be free of the toxic problems associated with lead-based
solders. The measurements have been carried out with a transient hot-wire
instrument originally designed for the measurement of the thermal conductivity
of pure molten metals. In the application reported here the instrument
has been used largely unchanged but an improved finite-element code has
been used for the analysis of the raw data so as to yield the thermal conductivity
of the molten solders. The measurements extend from the melting
point of the solder up to 625 K. The uncertainty in the thermal conductivity
measurements is estimated to be no larger than 3%
Repeatability and refinement of a transient hot wire instrument for measuring the thermal conductivity of high temperature melts
Simultaneous measurement of the density and viscosity of compressed liquid toluene
A vibrating-wire densimeter described previously has been used to perform simultaneous measurements of the density and viscosity of toluene at temperatures from 222 to 348 K and pressures up to 80 MPa. The density measurements are essentially based on the hydrostatic weighing principle, using a vibrating-wire device operated in forced mode of oscillation, as a sensor of the apparent weight of a cylindrical sinker immersed in the test fluid. The resonance characteristics for the transverse oscillations of the wire, which is also immersed in the fluid, are described by a rigorous theoretical model, which includes both the buoyancy and the hydrodynamic effects, owing to the presence of the fluid, on the wire motion. It is thus possible, from the working equations, to determine simultaneously, both the density and the viscosity of the fluid from the analysis of the resonance curve of the wire oscillation, the density being related essentially to the position of the maximum and the viscosity to its width. New results of measurements of the density and viscosity of toluene in the compressed liquid region are presented, and compared with literature data. The density results extend over a temperature range 222 K ? T ? 348 K, and pressures up to 80 MPa. The viscosity results cover a temperature range of 248 K ? T ? 348 K and pressures up to 80 MPa. The uncertainty of the present density data is estimated to be within ±0.1% at temperatures 298 K ? T ? 350 K, and ±0.15% at 222 K ? T ? 273 K. The corresponding overall uncertainty of the viscosity measurements is estimated to be ±2% for temperatures 298 K ? T ? 350 K, and ±3% for 248 K ? T ? 273 K
Densities and bubble points of binary mixtures of carbon dioxide and n-heptane and ternary mixtures of n-butane, n-heptane and n-hexadecane
The densities of three mixtures of carbon dioxide and n-heptane and three mixtures of n-butane, n-heptane and n-hexadecane were measured. The binary mixtures were studied over the temperature range of 302–459 K and the pressure range of 3.61–55.48 MPa at the following carbon dioxide mole fractions: 0.2918, 0.3888 and 0.4270. The ternary mixtures were studied over the temperature range of 405–469 K and the pressure range of 0.7–24 MPa at the following n-butane mole fractions: 0.0904, 0.1564 and 0.1856 and corresponding n-heptane mole fractions: 0.7358, 0.6825 and 0.6588. The measurements were carried out in an automated isochoric instrument and their accuracy is estimated to be better than ±0.1%. The bubble points of the mixtures were also determined from an analysis of the experimental isochores in the one- and two-phase regions. The new measurements have been used to assess the performance of the Peng–Robinson equation of state and the one-fluid corresponding states model. In single phase regions, the performance of the one-fluid model is found to be superior to that of the Peng–Robinson equation. The latter performs well for bubble points provided that optimised interaction parameters are used. As an interpolation tool, the one fluid model is found to reproduce the ternary mixtures within the experimental uncertainty
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