36 research outputs found
Viscosity and Density of Five Hydrocarbon Liquids at Pressures up to 200 MPa and Temperatures up to 473 K
ppT measurements of polyethylene glycol dimethylethers between 278.15 and 328.15 K at pressures to 12 MPa
In this paper we present a new experimental apparatus designed to measure
pressure density temperature ( p\T) properties with a high-pressure vibrating
tube densimeter. Data reliability has been verified by comparing our experimental
results for methanol, n-heptane, toluene, and HFC-134a with literature data. In
this work we also report new experimental densities from 278.15 to 328.15 K, and
up to 12 MPa, of triethylene glycol dimethylether (TrEGDME) and tetraethylene
glycol dimethylether (TEGDME). The isobaric thermal expansion coefficients,
isothermal compressibility, and internal pressure have been calculated. The
dependence of these properties on the length of polyethylene glycol dimethyl ether, CH3O ((CH2)2O)n CH3 , is analyzed.info:eu-repo/semantics/publishedVersio
Volumetric Properties of Monoethylene Glycol Dimethyl Ether and Diethylene Glycol Dimethyl Ether up to 60 MPa
Dynamic Viscosity under Pressure for Mixtures of Pentaerythritol Ester Lubricants with 32 Viscosity Grade:Â Measurements and Modeling
High-Pressure Thermophysical Properties of Eight Paraffinic, Naphthenic, Polyalphaolefin and Ester Base Oils
In this work, the thermophysical properties of four mineral (paraffinic and naphthenic) and four synthetic (polyalphaolefin and ester) base oils are measured. Knowledge of these properties is of vital importance for the correct and optimal formulation and design of lubricants, and for the development of equations of state and transport models that adequately represent their properties. Density, isothermal compressibility, thermal expansion coefficient, dynamic viscosity, pressureâviscosity coefficient, and contact angle were determined. To carry out this work, a pÏT apparatus, a rotational viscometer, a falling body viscometer, and a contact angle analyzer were used. Highest densities were found for the polyalphaolefin and ester synthetic oils, increasing around 5% from 0.1 to 100 MPa for all the base oils. The density of the synthetic oils is less dependent on temperature changes. For the expansivity and compressibility of all the base oils, decreases with pressure of up to 35% and 45% were observed. From the contact angle measurements, it was observed that base oils with a higher viscosity grade have a worse wetting. The greatest effect of pressure on the dynamic viscosity was obtained for the naphthenic mineral oil and the lowest effect for the polyalphaolefin oil. Paraffinic and naphthenic oils present the highest universal pressureâviscosity coefficients
High-Pressure Thermophysical Properties of Eight Paraffinic, Naphthenic, Polyalphaolefin and Ester Base Oils
In this work, the thermophysical properties of four mineral (paraffinic and naphthenic) and four synthetic (polyalphaolefin and ester) base oils are measured. Knowledge of these properties is of vital importance for the correct and optimal formulation and design of lubricants, and for the development of equations of state and transport models that adequately represent their properties. Density, isothermal compressibility, thermal expansion coefficient, dynamic viscosity, pressure–viscosity coefficient, and contact angle were determined. To carry out this work, a pρT apparatus, a rotational viscometer, a falling body viscometer, and a contact angle analyzer were used. Highest densities were found for the polyalphaolefin and ester synthetic oils, increasing around 5% from 0.1 to 100 MPa for all the base oils. The density of the synthetic oils is less dependent on temperature changes. For the expansivity and compressibility of all the base oils, decreases with pressure of up to 35% and 45% were observed. From the contact angle measurements, it was observed that base oils with a higher viscosity grade have a worse wetting. The greatest effect of pressure on the dynamic viscosity was obtained for the naphthenic mineral oil and the lowest effect for the polyalphaolefin oil. Paraffinic and naphthenic oils present the highest universal pressure–viscosity coefficients