Reference Correlations for the Viscosity and Thermal Conductivity of n-Undecane

Abstract

This paper presents new wide-ranging correlations for the viscosity and thermal conductivity of n-undecane based on critically evaluated experimental data. The correlations are designed to be used with a recently published equation of state that is valid from the triple point to 700 K, at pressures up to 500 MPa, with densities below 776.86 kg m−3. The estimated uncertainty for the dilute-gas viscosity is 2.4%, and the estimated uncertainty for viscosity in the liquid phase for pressures up to 60 MPa over the temperature range 260 K to 520 K is 5%. The estimated uncertainty is 3% for the thermal conductivity of the low-density gas, and 3% for the liquid over the temperature range from 284 K to 677 K at pressures up to 400 MPa. Both correlations behave in a physically reasonable manner when extrapolated to the full range of the equation of state, however care should be taken when using the correlations outside of the validated range. The uncertainties will be larger outside of the validated range, and also in the critical region.

Reference Correlation of the Viscosity of n-Hexadecane from the Triple Point to 673 K and up to 425 MPa

“…n-Hexadecane (n-C 16 H 34 ) is a normal, paraffinic alkane that is naturally found in oil and is an important constituent of aviation and diesel fuel. It is sometimes referred by its old name, cetane, and is assigned a cetane number of 100, thus serving as a reference fuel for measuring the quality of diesel.…”

“…3,9 Based on the previous studies, [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] the viscosity critical enhancement of n-hexadecane is taken as zero. The total lack of industrial applications of n-hexadecane near its critical temperature and the lack of the experimental viscosity data in the neighborhood of the critical point further supports this choice.…”

“…This is especially important for naturally occurring mixtures that contain a myriad of species, where the presence of long-chain species increases viscosity significantly. For a number of industrially important fluids (simple fluids, [3][4][5][6] water, 7 normal alkanes, [8][9][10][11][12][13][14][15][16][17] cyclic and aromatic hydrocarbons [18][19][20][21][22][23][24] and refrigerants [25][26][27] ) there exist accurate and reliable correlations of viscosity that cover a wide range of temperatures and pressures, with well-defined estimates of uncertainty. The aim of the present study is to critically assess the viscosity data available in the literature and provide a correlation for the viscosity of nhexadecane that is valid over a wide range of temperature and pressure, covering the vapor, liquid, and supercritical fluid states.…”

“…Thus, expanding the set of viscosity correlations that are available for n-alkanes that currently encompass methane to n-butane [8][9][10][11] and n-hexane to n-dodecane. [12][13][14][15][16][17] The work is continuation of the program to develop representations of the viscosity and thermal conductivity of pure fluids that is carried out under the auspices of the International Association for Transport Properties (IATP) a Subcommittee of the…”

Reference Correlation for the Thermal Conductivity of Ammonia from the Triple-Point Temperature to 680 K and Pressures up to 80 MPa

“…In a series of recent papers, new reference correlations for the thermal conductivity of some simple fluids, [1][2][3][4] hydrocarbons, [5][6][7][8][9][10][11][12][13] alcohols, 14 and refrigerants 15,16 were reported. In this paper, the methodology adopted in the aforementioned papers is extended to developing a new reference correlation for the thermal conductivity of ammonia.…”