High-pressure Viscosity Measurements Research Articles

Experimental Study of the Effect of Temperature, Pressure, and Concentration on the Viscosity of Aqueous SrCl2 Solutions in the Range of (293 to 473) K and (0.1 to 20) MPa

The viscosity of five [(0.27, 0.58, 0.92, 1.73, and 2.63) mol·kg-1] binary aqueous SrCl2 solutions has been measured with a capillary flow technique. Measurements were made at pressures up to 20 MPa. The range of temperature was (293 to 473) K. The total uncertainties in viscosity, pressure, temperature, and composition measurements were estimated to be less than 1.6 %, 0.05 %, 15 mK, and 0.02 %, respectively. The effects of temperature, pressure, and concentration on the viscosity of SrCl2(aq) solutions were studied. The temperature and pressure coefficients of the viscosity of SrCl2(aq) were studied as a function of concentration and temperature. The measured values of viscosity were compared with data, predictions, and correlations reported in the literature. The viscosity data were used to accurately calculate the physical meaning parameters (viscosity A and B coefficients) in the extended Jones−Dole equation for the relative viscosity (η/η0). Various theoretical models [absolute rate theory, TTG (Tammann−Tait−Gibson) model, extended Einstein model] were used to accurately represent the measured values of viscosity. The values of hydrodynamic molar volume, Vk (effective rigid molar volume of salt), were calculated using the present experimental viscosity data. The high-pressure viscosity measurements were used to test the predictive capability of the TTG model.

5231 植物油脂系生分解性油の2.5GPaまでの高圧粘度測定とトライボロジー特性(S66-2 サステイナブルトライボロジー(2),S66 サステイナブルトライボロジー)

5231 植物油脂系生分解性油の2.5GPaまでの高圧粘度測定とトライボロジー特性(S66-2 サステイナブルトライボロジー(2),S66 サステイナブルトライボロジー)

Experimental Dynamic Viscosities of 2,3-Dimethylpentane up to 60 MPa and from (303.15 to 353.15) K Using a Rolling-Ball Viscometer

The main motivation of this work is to verify the reliability of a high-pressure viscosity measurement technique that was recently installed in our laboratory. A total of 2520 experimental measurements of the rolling time have been performed. Hexane and decane were used to calibrate the apparatus, and the dynamic viscosity of heptane has been measured to verify the calibration method. Our results agree with the literature values with average absolute deviations lower than the experimental uncertainty (±2%). In a second step, hexane, heptane, and decane have been used as reference substances, and the calibration has been verified again by determining the dynamic viscosity of toluene. A comparison has been established between the experimental dynamic viscosity measured in this work for toluene and the reference correlation recommended by IUPAC, obtaining an absolute average deviation of 0.9% and a maximum deviation of 2%. Furthermore, 99 density (up to 45 MPa and from 298.15 K to 353.15 K) and 84 dynamic vi...

Reference Correlation for the Viscosity of Liquid Cyclopentane from 220 to 310 K at Pressures to 25 MPa

A correlation in terms of temperature and molar volume is recommended for the viscosity of liquid cyclopentane as a reference for low-temperature, high-pressure viscosity measurements. The temperature range covered is from 220 to 310 K and the pressure range from atmospheric up to 25 MPa. The standard deviation of the proposed correlation, within a 95% confidence limit, is 1%.

Towards evaluating the viscosity of the Earth's outer core: An experimental high pressure study of liquid Fe‐S (8.5 wt.% S)

In‐situ high pressure viscosity measurements, using synchrotron X‐ray radiography, have been carried out on liquid Fe‐S (8.5 wt.% S) at pressures up to 6 GPa and at 1823 K. Here we show that (i) the effect of pressure on the isothermal viscosity is substantial, with an apparent activation volume of 5.8 cm3/mol; and (ii) viscosity is constant along the pressure dependent melting boundary. Assuming the independence of viscosity along the melting boundary up to core pressures, our results yield a viscosity for the Earth's outer core, at the inner core boundary, of 1.6 × 10−2 Pa s. On this basis, we present a revised viscosity profile across the outer core.

2448 トライボ CAD のための潤滑油高圧粘度・密度測定

2448 トライボ CAD のための潤滑油高圧粘度・密度測定

Reference correlation for the viscosity of liquid toluene from 213 to 373 K at pressures to 250 MPa

A correlation in terms of temperature and molar volume is recommended for the viscosity of liquid toluene as a reference for high-pressure viscosity measurements. The temperature range covered is from 213 to 373 K, and the pressure range from atmospheric up to 250 MPa. The standard deviation of the proposed correlation is 1.36%, and, within a 95% confidence limit, the error is 2.7%. It is estimated that for densities up to 920 kg·m−3the uncertainty of the viscosity values generated by this correlation is about ±2%.

High pressure viscosity and density measurements of the binary mixture tridecane + 2,2,4,4,6,8,8-heptamethylnonane

The dynamic viscosity η of the binary mixture tridecane + 2,2,4,4,6,8-heptamethyl-nonane has been measured in the temperature range 293.15-353.15K (in progressive 10 K steps) at pressures 0.1,20,40,60,80 and 100 MPa. The system is described by 9 molar fractions (0 to 1 in 0.125 progressive steps). The density ρ has been measured at pressures from 0.1 to 65 MPa in progressive 5 MPa steps. The whole set of experimental data represents 378 points for η and 882 for ρ. The measurements of η allow to determine the excess viscosity ηE and the excess activation energy of viscous flow ΔGE versus pressure, temperature and composition.

Density-mediated transport and the glass transition: high pressure viscosity measurements in the diamond anvil cell

Three methods have been recently demonstrated for obtaining accurate high pressure viscosity data which combine to give a viscosity range of ten decades. Dynamic light scattering is useful in the range 10 −1–10 2 cP, the rolling-ball diamond-cell viscometer covers the range 10 −1–10 7 cP and the centrifugal-force diamond-cell viscometer operates in the 10 5–10 9 cP range. The overall accuracy of these devices is 10% or better. Within this accuracy, it is found that the simple free-volume model describes the high-pressure data over wide compression ranges. Several features of these fits are noteworthy. First, extrapolation of the fitted function to 10 15 cP yields a calculated pressure, P ∗ , which correlates well with the glass transition pressure obtained experimentally by other techniques. Second, the effective molecule diameter obtained from the free-volume fits is considerably different from that obtained from thermal data, but the diameter is comparable to the effective hard-sphere diameter obtained from a modified Carnahan-Starling—van der Waals equation of state model. Third, it is found that a scaling behavior, analogous to that of fragility for thermal data, is obtained when the viscosity data are plotted versus the volume normalized to that calculated at P ∗ .

Raman spectroscopy in liquids at high pressure

The pressure dependence of the reorientational correlation function for chloroform has been measured by analysis of the Raman 3019 cm − 1 A 1 CH stretching lineshape at 1, 1000, and 2000 bar and 23°C. These reorientational correlation functions were obtained using the method of spectral Fourier deconvolution introduced by Bratos. The results are compared to the correlation times obtained from the NMR deuteron T 1 relaxation times for CDCl 3 and those calculated from high pressure viscosity measurements.