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Displaying 151 - 175 of 403

Viscosity-ratio measurements with capillary viscometers

November 27, 2013

Author(s)

Robert F. Berg, Eric F. May, Michael R. Moldover

Viscosity-ratio measurements made with capillary viscometers exploit the accurate values of the viscosity of helium calculated ab initio. Accurate values of the argon-to-helium viscosity ratio are now used for primary acoustic gas thermometry and for the

Reference Correlation of the Thermal Conductivity of Methanol from the Triple Point to 665 K and up to 245 MPa

November 26, 2013

Author(s)

E.A. Sykioti, Marc J. Assael, Marcia L. Huber, Richard A. Perkins

This paper contains new, representative reference equations for the thermal conductivity of methanol. The equations are based in part upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory

A thermodynamic analysis of refrigerants: Possibilities and tradeoffs for Low-GWP refrigerants

October 26, 2013

Author(s)

Mark O. McLinden, Andrei F. Kazakov, J. Steven Brown, Piotr A. Domanski, Jae H. Heo

We explore the possibilities for refrigerants having low global warming potential (GWP) using two distinct, but complimentary, approaches. We evaluate the effect of a refrigerant's fundamental thermodynamic parameters on its performance in the simple vapor

Connection between thermodynamics and dynamics of simple fluids in highly attractive pores

October 25, 2013

Author(s)

William P. Krekelberg, Vincent K. Shen, Daniel W. Siderius, Thomas M. Truskett, Jeffrey R. Errington

We investigate the structural and diffusive dynamics properties of a model fluid in highly-absorptive cylindrical pores. At subcritical temperatures, self diffusion displays three distinct regimes as a function of average pore density ρ: 1) a decrease in

The Seventh Industrial Fluid Properties Simulation Challenge

October 8, 2013

Author(s)

Riaz Ahmad, John K. Brennan, Kevin A. Frankel, Jonathan D. Moore, Joshua D. Moore, Raymond D. Mountain, Richard B. Ross, Vincent K. Shen, Nathan E. Schultz, Daniel Siderius, Kenneth D. Smith, Matthias Thommes

The primary goal of the seventy industrial fluid properties simulation challenge was to test the ability of molecular simulation methods to predict the adsorption of organic adsorbates in zeolite materials. Zeoliet adsorbents are used in a variety of

A note on the critical enhancement of transport properties and correlation length of fluids

October 6, 2013

Author(s)

Richard A. Perkins, Jan V. Sengers

The thermal conductivity and viscosity are known to exhibit an enhancement in fluids due to critical fluctuations. We have reviewed procedures proposed in the literature for estimating the correlation length determining the magnitude of these enhancements

Reference Correlation of the Viscosity of n-Hexane from the Triple Point to 600 K and up to 100 MPa

September 10, 2013

Author(s)

E.K. Michailidou, Marc J. Assael, Marcia L. Huber, Richard A. Perkins

This paper contains new, representative reference equations for the viscosity of n-hexane. The equations are based in part upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory whenever

Wide Ranging Viscosity Measurements of Rocket Propellant RP-2

August 28, 2013

Author(s)

Arno D. Laesecke, Dylan S. Cousins

Expanding on earlier viscosity measurements of rocket propellants from 293 K to 373 K at atmospheric pressure, the viscosity of rocket propellant RP-2 was measured from 270 K to 450 K with pressures to 137 MPa. The instrument was an oscillating piston

Improved Determination of the Boltzmann Constant using a Single, Fixed-Length Cylindrical Cavity

August 27, 2013

Author(s)

Hong Lin, Keith A. Gillis, XiaoJuan Feng, Michael R. Moldover, J.P. Sun, J.T. Zhang, Y.Y. Duan

We report improvements to our previous [Zhang et al., Intl. J. Thermophysics, 32, 1297 (2011)] determination of the Boltzmann constant kB using a single 80 mm-long cylindrical cavity. In this work, the shape of the gas-filled resonant cavity is closer to

Thermal Stability of RP-2 as a Function of Composition: The Effect of Linear, Branched, and Cyclic Alkanes

August 22, 2013

Author(s)

Jason A. Widegren, Thomas J. Bruno

The objective of this work is to identify compositional changes that could improve the thermal stability of RP-2. For this study, we tested the effect of alkane concentration on the thermal stability of the RP-2 sample known as 08POSF5433. The proportion

A Thermodynamic Analysis of Refrigerants. II. Possibilities and Tradeoffs for Low-GWP Refrigerants

June 17, 2013

Author(s)

Mark O. McLinden, Andrei F. Kazakov, J. Steven Brown, Piotr A. Domanski

We explore the possibilities for refrigerants having low global warming potential (GWP) by use of two distinct approaches. In a companion paper (Domanski et al., 2013) we evaluate the effect of a refrigerants fundamental thermodynamic parameters on its

The continuum absorption in H2O+N2 mixture in the 3 - 5 ?m spectral region at temperatures from 326 to 363 K

June 13, 2013

Author(s)

Yuri I. Baranov

The absorption spectra of H2O+N2 mixtures, as well, as the spectra of pure gases, have been measured using a Fourier-transform infrared spectrometer at a resolution of 0.1 cm-1. The sample temperatures were 325, 339, 353, and 364 K. Water vapor pressures

NIST/ASME Steam Properties, Version 3.0

June 3, 2013

Author(s)

Allan H. Harvey, Eric W. Lemmon

This is an update of NIST Standard Reference Database 10. The main purpose of the update is to convert the database to a new graphical user interface that works on 64-bit machines.

Microwave measurements for gas thermometry up to the copper point

May 13, 2013

Author(s)

XiaoJuan Feng, Keith A. Gillis, Michael R. Moldover, James B. Mehl

We measured 5 microwave resonance frequencies f N of an argon-filled cylindrical cavity at temperatures up to 1349 K. The repeatability of both the measured frequencies u(f N) and the scaled half-widths u(g N)/ f N was better than 10 -6f N. The measurement

Three-body nonadditive potential for argon with estimated uncertainties and third virial coefficient

May 8, 2013

Author(s)

Allan H. Harvey, Mark O. McLinden, Wojciech Cencek, Krzysztof Szalewicz, Giovanni Garberoglio

The three-body nonadditive interaction energy between argon atoms was calculated at 300 geometries using coupled cluster methods up to single, double, triple, and noniterative quadruple excitations [CCSDT(Q)], and including the core correlation and

NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP, Version 9.1

May 7, 2013

Author(s)

Eric W. Lemmon, Marcia L. Huber, Mark O. McLinden

This is a new release of the NIST Standard Reference Database 23, commonly known as REFPROP. Enhancements have been made to most areas of the NIST REFPROP program, including the graphical interface, the Excel spreadsheet, the FORTRAN files (i.e., core

Assessment of the Thermophysical Properties of Thermally Stressed RP-1 and RP-2

May 2, 2013

Author(s)

Tara J. Fortin, Thomas J. Bruno

Density, speed of sound, and viscosity have been measured for samples of RP-1 and RP-2 that were stressed for 0.5 min at 475 °C and 510 °C at a pressure of 17 MPa. Density and speed of sound were measured from 5 °C to 50 °C for the samples stressed at 475

Reference Correlation of the Thermal Conductivity of Ethanol from the Triple Point to 600 K and up to 250 MPa

April 26, 2013

Author(s)

Marc J. Assael, E.A. Sykioti, Marcia L. Huber, Richard A. Perkins

This paper contains new, representative reference equations for the thermal conductivity of ethanol. The equations are based in part upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory

Reference Correlation of the Thermal Conductivity of n-Heptane from the Triple Point to 600 K and up to 250 MPa

April 1, 2013

Author(s)

Marc J. Assael, I. Bogdanou, Sofia K. Mylona, Marcia L. Huber, Richard A. Perkins, Velisa Vesovic

This paper contains new, representative reference equations for the thermal conductivity of n-heptane. The equations are based in part upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory

Correlation for the Viscosity of Hydrogen obtained from Symbolic Regression

March 27, 2013

Author(s)

Chris D. Muzny, Marcia L. Huber, Andrei F. Kazakov

We report the results of a symbolic regression methodology to obtain both the functional form and the coefficients for a wide-ranging correlation for the viscosity of normal hydrogen. The correlation covers the temperature range from the triple point

Reference Correlation of the Thermal Conductivity of n-Hexane from the Triple Point to 600 K and up to 500 MPa

March 11, 2013

Author(s)

Marc J. Assael, Sofia K. Mylona, Ch. A. Tsiglifisi, Marcia L. Huber, Richard A. Perkins

This paper contains new, representative reference equations for the thermal conductivity of n-hexane. The equations are based in part upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory

Critical thermal-conductivity enhancement in molecular fluids

March 2, 2013

Author(s)

Richard A. Perkins, Jan V. Sengers, Ilmutdin M. Abdulagatov, Marcia L. Huber

The available information for the thermal-conductivity enhancement is reviewed. We show that it can be represented by a simplified solution of the mode-coupling theory of critical dynamics with two critical amplitudes and one cutoff wave number as fluid

Experimental Study of the Thermal Conductivity of Water +Ammonia Refrigerant Mixtures at Temperatures from 278 K to 356 K and at Pressures up to 20 MPa

February 28, 2013

Author(s)

F. N. Shamsetdinov, Z. I. Zaripov, Ilmutdin M. Abdulagatov, Marcia L. Huber, F. M. Gumerov, F. R. Gabitov, Andrei F. Kazakov

The thermal conductivity of binary water + ammonia mixtures was measured over the temperature range from 278 K to 356 K and at pressures up to 20 MPa using the steady-state hot-wire method. Measurements were made for eight compositions over the entire

Advanced Calibration, Adjustment, and Operation of a Density and Sound Speed Analyzer

February 26, 2013

Author(s)

Tara J. Fortin, Arno D. Laesecke, Malte B. Freund, Stephanie L. Outcalt

Benchtop measurement systems have emerged as powerful tools in the ongoing quest for thermophysical property data. We demonstrate that these instruments can yield high quality data if operated in an informed manner. The importance of sample purity

Molecular dynamics simulation of water-acetonitrile mixtures in a silica slit

February 6, 2013

Author(s)

Raymond D. Mountain

Molecular dynamics simulations of aqueous acetonitrile confined in a planar silica slit are presented. It is found, in agreement with experimental observations, that a thin layer of water that excludes acetonitrile is in contact with the hydrophillic