Pressure and temperature dependence of the surface tension in the system natural gas/water principles of investigation and the first precise experimental data for pure methane/water at 25°C up to 46.8 MPa

Developing novel correlations for calculating natural gas thermodynamic properties Natural gas is a mixture of 21 components and it is widely used in industries and homes. Knowledge of its thermodynamic properties is essential for designing appropriate processes and equipment. This paper presents simple but precise correlations of how to compute important thermodynamic properties of natural gas. As measuring natural gas composition is costly and may not be effective for real time process, the correlations are developed based on measurable real time properties. The real time properties are temperature, pressure and specific gravity of the natural gas. Calculations with these correlations are compared with measured values. The validations show that the average absolute percent deviation (AAPD) for compressibility factor calculations is 0.674%, for density is 2.55%, for Joule-Thomson coefficient is 4.16%. Furthermore, in this work, new correlations are presented for computing thermal properties of natural gas such as enthalpy, internal energy and entropy. Due to the lack of experimental data for these properties, the validation is done for pure methane. The validation shows that AAPD is 1.31%, 1.56% and 0.4% for enthalpy, internal energy and entropy respectively. The comparisons show that the correlations could predict natural gas properties with an error that is acceptable for most engineering applications.

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TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v5i3.1887 ◽

2014 ◽

Vol 5 (3) ◽

pp. 982-992 ◽

Cited By ~ 1

Author(s):

M AL-Jalali

Keyword(s):

Experimental Data ◽

Electrical Resistivity ◽

Temperature Dependence ◽

Concentration Dependence ◽

Low Temperatures ◽

Noble Metals ◽

Phonon Scattering ◽

Theoretical Models ◽

Residual Resistivity ◽

Electron Phonon Scattering

Resistivity temperature â€“ dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron â€“ dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

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Revisiting Kelvin equation and Peng–Robinson equation of state for accurate modeling of hydrocarbon phase behavior in nano capillaries

Scientific Reports ◽

10.1038/s41598-021-86075-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ilyas Al-Kindi ◽

Tayfun Babadagli

Keyword(s):

Experimental Data ◽

Surface Tension ◽

Equation Of State ◽

Phase Behavior ◽

Pore Radius ◽

Microfluidic Chips ◽

Tight Sandstone ◽

Kelvin Equation ◽

Rock Samples ◽

Robinson Equation

AbstractThe thermodynamics of fluids in confined (capillary) media is different from the bulk conditions due to the effects of the surface tension, wettability, and pore radius as described by the classical Kelvin equation. This study provides experimental data showing the deviation of propane vapour pressures in capillary media from the bulk conditions. Comparisons were also made with the vapour pressures calculated by the Peng–Robinson equation-of-state (PR-EOS). While the propane vapour pressures measured using synthetic capillary medium models (Hele–Shaw cells and microfluidic chips) were comparable with those measured at bulk conditions, the measured vapour pressures in the rock samples (sandstone, limestone, tight sandstone, and shale) were 15% (on average) less than those modelled by PR-EOS.

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Ability of Constitutive Models to Characterize the Temperature Dependence of Rubber Hyperelasticity and to Predict the Stress-Strain Behavior of Filled Rubber under Different Defor Mation States

Polymers ◽

10.3390/polym13030369 ◽

2021 ◽

Vol 13 (3) ◽

pp. 369

Author(s):

Xintao Fu ◽

Zepeng Wang ◽

Lianxiang Ma

Keyword(s):

Experimental Data ◽

Temperature Dependence ◽

Mechanical Response ◽

Constitutive Models ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Chain Model ◽

Stress Strain ◽

Filled Rubber ◽

Yeoh Model

In this paper, some representative hyperelastic constitutive models of rubber materials were reviewed from the perspectives of molecular chain network statistical mechanics and continuum mechanics. Based on the advantages of existing models, an improved constitutive model was developed, and the stress–strain relationship was derived. Uniaxial tensile tests were performed on two types of filled tire compounds at different temperatures. The physical phenomena related to rubber deformation were analyzed, and the temperature dependence of the mechanical behavior of filled rubber in a larger deformation range (150% strain) was revealed from multiple angles. Based on the experimental data, the ability of several models to describe the stress–strain mechanical response of carbon black filled compound was studied, and the application limitations of some constitutive models were revealed. Combined with the experimental data, the ability of Yeoh model, Ogden model (n = 3), and improved eight-chain model to characterize the temperature dependence was studied, and the laws of temperature dependence of their parameters were revealed. By fitting the uniaxial tensile test data and comparing it with the Yeoh model, the improved eight-chain model was proved to have a better ability to predict the hyperelastic behavior of rubber materials under different deformation states. Finally, the improved eight-chain model was successfully applied to finite element analysis (FEA) and compared with the experimental data. It was found that the improved eight-chain model can accurately describe the stress–strain characteristics of filled rubber.

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Surface Tension and Density of Liquid Hot Work Tool Steel W360 by voestalpine BÖHLER Edelstahl GmbH & Co KG Measured with an Electromagnetic Levitation Apparatus

International Journal of Thermophysics ◽

10.1007/s10765-020-02765-x ◽

2020 ◽

Vol 42 (2) ◽

Author(s):

Thomas Leitner ◽

Anna Werkovits ◽

Siegfried Kleber ◽

Gernot Pottlacher

Keyword(s):

Surface Tension ◽

Temperature Dependence ◽

Linear Model ◽

Tool Steel ◽

Pure Iron ◽

Electromagnetic Levitation ◽

Liquid Density ◽

Hot Work Tool Steel ◽

Significant Difference ◽

Main Component

AbstractW360 is a hot work tool steel produced by voestalpine BÖHLER Edelstahl GmbH & Co KG, a special steel producer located in Styria, Austria. Surface tension and density of liquid W360 were studied as a function of temperature in a non-contact, containerless fashion using the oscillating drop method inside an electromagnetic levitation setup. For both, surface tension and density, a linear model was adapted to present the temperature dependence of these measures, including values for the uncertainties of the fit parameters found. The data obtained are compared to pure iron (with 91 wt% the main component of W360), showing an overlap for the liquid density while there is a significant difference in surface tension (− 5.8 % at the melting temperature of pure iron of 1811 K).

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Design Analysis of a Micro Gas Turbine Combustion Chamber Burning Natural Gas

Volume 5: Manufacturing Materials and Metallurgy; Marine; Microturbines and Small Turbomachinery; Supercritical CO2 Power Cycles ◽

10.1115/gt2012-69180 ◽

2012 ◽

Cited By ~ 1

Author(s):

André Perpignan V. de Campos ◽

Fernando L. Sacomano Filho ◽

Guenther C. Krieger Filho

Keyword(s):

Experimental Data ◽

Natural Gas ◽

Combustion Chamber ◽

Gas Turbines ◽

Low Cost ◽

Mixture Fraction ◽

Combustion Model ◽

Inlet Temperature ◽

Gas Combustion ◽

Micro Turbine

Gas turbines are reliable energy conversion systems since they are able to operate with variable fuels and independently from seasonal natural changes. Within that reality, micro gas turbines have been increasing the importance of its usage on the onsite generation. Comparatively, less research has been done, leaving more room for improvements in this class of gas turbines. Focusing on the study of a flexible micro turbine set, this work is part of the development of a low cost electric generation micro turbine, which is capable of burning natural gas, LPG and ethanol. It is composed of an originally automotive turbocompressor, a combustion chamber specifically designed for this application, as well as a single stage axial power turbine. The combustion chamber is a reversed flow type and has a swirl stabilized combustor. This paper is dedicated to the diagnosis of the natural gas combustion in this chamber using computational fluid dynamics techniques compared to measured experimental data of temperature inside the combustion chamber. The study emphasizes the near inner wall temperature, turbine inlet temperature and dilution holes effectiveness. The calculation was conducted with the Reynolds Stress turbulence model coupled with the conventional β-PDF equilibrium along with mixture fraction transport combustion model. Thermal radiation was also considered. Reasonable agreement between experimental data and computational simulations was achieved, providing confidence on the phenomena observed on the simulations, which enabled the design improvement suggestions and analysis included in this work.

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Concentration Dependence of the Surface Tension of Three and Four-Component Systems with Peculiarities in the Surface Tension Isotherms of Lateral Binary Melts

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1022.194 ◽

2021 ◽

Vol 1022 ◽

pp. 194-202

Author(s):

R.Kh. Dadashev ◽

R.A. Kutuev

Keyword(s):

Experimental Data ◽

Surface Tension ◽

Concentration Dependence ◽

Experimental Error ◽

Binary Systems ◽

Experimental Studies ◽

Study Results ◽

Component Systems ◽

Minimum Depth ◽

Surface Tension Isotherms

The experimental study results of the melts concentration dependence of the surface tension of the four-component indium-tin-lead-bismuth system and its constituent binary systems of indium-tin, indium-lead, indium-bismuth, tin-lead, tin-bismuth, lead-bismuth are presented in the paper. It is shown that the concentration dependence of the melts surface tension of the In-Sn-Pb-Bi four-component system can be predicted from the data on ST (surface tension) values of lateral binary systems. Features in the ST isotherms in the form of a minimum are observed only in the indium-tin lateral system from all lateral binaries. A distinctive feature of the detected minimum is that the minimum depth slightly exceeds the experimental error. Therefore, in addition to the fact that the area of average compositions was studied more thoroughly, we carried out the surface tension measurements by two independent methods. The experimental data obtained by both methods coincide within the experimental error and indicate the extremum availability on ST isotherms. Thus, ST experimental studies by two independent methods confirmed the presence of a flat minimum on ST isotherms of the indium-tin binary system increasing the reliability of the obtained data. The obtained outcomes and their comparison with experimental data have shown that the considered models for predicting surface properties based on data due to similar properties of lateral binary systems adequately reflect the experimental dependences. However, the prediction model based on Kohler's method of excess values describes the experimental curves more accurately.

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Interaction of Point Defects in Ice

Journal of Glaciology ◽

10.3189/s0022143000033359 ◽

1978 ◽

Vol 21 (85) ◽

pp. 115-122

Author(s):

J. H. Bilgram ◽

H. Gränicher

Keyword(s):

Experimental Data ◽

Dielectric Properties ◽

Temperature Dependence ◽

Point Defects ◽

Low Frequency ◽

Defect Concentration ◽

Dielectric Measurements ◽

Long Time ◽

Nmr Techniques ◽

Bjerrum Defect

AbstractThe interaction of point detects in ice has been neglected for a long time. Experimental data obtained from dielectric measurements on HF-doped crystals stimulated a new evaluation of the possibility of an interaction between Bjerrum defects and ions. In a previous paper it has been shown that this leads us to assume the existence of aggregates of Bjerrum defects and ions. In this paper these aggregates and Bjerrum defects are used to explain the dielectric properties of ice, especially the temperature dependence of the product of the high and low frequency conductivity σ0σ∞.The interaction of Bjerrum defects and impurity molecules leads to a dependence of the concentration of frenkel pairs on Bjerrum-defect concentration. At HF concentrations above the native Bjerrum-defect concentration the formation of a Frenkel pair is enhanced. This leads to the fast out-diffusion which has been studied in highly doped crystals by means of NMR techniques.

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TEMPERATURE-DEPENDENCE OF PROTON CONDUCTIVITY IN HYDROGEN-BONDED MOLECULAR SYSTEMS

Modern Physics Letters B ◽

10.1142/s0217984907013432 ◽

2007 ◽

Vol 21 (19) ◽

pp. 1239-1252 ◽

Cited By ~ 1

Author(s):

XIAO-FENG PANG ◽

BO DENG ◽

HUAI-WU ZHANG ◽

YUAN-PING FENG

Keyword(s):

Experimental Data ◽

Electric Field ◽

Temperature Dependence ◽

Electric Conductivity ◽

Proton Conductivity ◽

Model System ◽

Time Dependent ◽

Molecular Systems ◽

Damping Effect ◽

Hydrogen Bonded

The temperature-dependence of proton electric conductivity in hydrogen-bonded molecular systems with damping effect was studied. The time-dependent velocity of proton and its mobility are determined from the Hamiltonian of a model system. The calculated mobility of (3.57–3.76) × 10-6 m 2/ Vs for uniform ice is in agreement with the experimental value of (1 - 10) × 10-2 m 2/ Vs . When the temperature and damping effects of the medium are considered, the mobility is found to depend on the temperature for various electric field values in the system, i.e. the mobility increases initially and reaches a maximum at about 191 K, but decreases subsequently to a minimum at approximately 241 K, and increases again in the range of 150–270 K. This behavior agrees with experimental data of ice.

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