Revisiting the Compressibility of Oil/Refrigerant Lubricants

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Scott Bair ◽  
Mark Baker ◽  
David M. Pallister

A fixture was fabricated for the purpose of restraining the expansion of an existing metal bellows piezometer so that a refrigerant and oil mixture can be admitted under pressure. Measurements on a polyol ester (POE) with 9.2 wt.% of R134a show that the addition of refrigerant slightly increases compressibility. The previously reported reduction in compressibility (increase in bulk modulus) by Tuomas and Isaksson (2006, “Compressibility of Oil/Refrigerant Lubricants in Elasto-Hydrodynamic Contacts,” ASME J. Tribol., 128(1), pp. 218–220) of an ISO 68 POE when mixed with R134a cannot be supported by precise measurements of the volume compression. The increased compressibility found by Comuñas and co-workers (2002, “High-Pressure Volumetric Behavior of x 1, 1, 1, 2-Tetrafluoroethane + (1 − x) 2, 5, 8, 11, 14-Pentaoxapentadecane (TEGDME) Mixtures,” J. Chem. Eng. Data, 47(2), pp. 233–238) is the correct trend. The Tait equation of state (EoS) has been fitted to the data for both the neat POE and its 9.2% by weight mixture with refrigerant. The usual problem was encountered for the mixture with the Tait EoS at low pressure where the compressibility becomes greater than predicted due to proximity to the vapor dome. The measured relative volumes of the mixture can be used to collapse the viscosity to a master curve when plotted against the Ashurst–Hoover thermodynamic scaling parameter. The thermodynamic scaling interaction parameter is approximately the same as for the neat oil.

1998 ◽  
Vol 103 (5) ◽  
pp. 3080-3080
Author(s):  
Bruce Hartmann ◽  
Gilbert F. Lee ◽  
Edward Balizer

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jeewan C. Bhatt ◽  
Kuldeep Kholiya ◽  
Ravindra Kumar

Shanker Equation of State is used to study the volume compression of nanocrystalline materials under different pressure. On comparing with the experimental data it gives good results at low pressure, but for higher compression it deviates from the experimental points. Therefore, the Equation of State is modified empirically to study the pressure-volume relation for nanomaterials, namely, n-Rb3C60, n-CdSe (rocksalt phase), n-TiO2 (anatase and rutile phase), Fe-filled nanotube, and γ-Fe2O3, at high pressure. The results obtained from the empirical Equation of State are found to be in better agreement with the available experimental data.


2019 ◽  
Vol 183 ◽  
pp. 108149 ◽  
Author(s):  
Jian Wang ◽  
Christian Hopmann ◽  
Mauritius Schmitz ◽  
Tobias Hohlweck ◽  
Jens Wipperfürth

1976 ◽  
Vol 49 (2) ◽  
pp. 207-209
Author(s):  
S. Beret ◽  
J. M. Prausnitz

Abstract Experimentally determined densities and compressibilities of amorphous polymers are frequently available; but, because of experimental difficulties, few experimental results have been reported at high pressures. Such densities, however, are sometimes required for rational design of extrusion and similar processes. We report here a simple method for estimating densities and compressibilities at high pressures from experimental compressibilities at low pressure. Our method is based on a relation for liquids suggested by Wada and developed by Chueh and Prausnitz. The purpose of this note is to suggest a method for estimating polymer densities at high pressure wherever experimental data are insufficient for obtaining parameters needed in an equation of state, as, for example, the Tait equation.


Author(s):  
Angélica Maria Chacón Valero ◽  
Caiuã Araújo Alves ◽  
Filipe Xavier Feitosa ◽  
Hosiberto Batista de Sant’Ana

1996 ◽  
Vol 14 (2) ◽  
pp. 157-169 ◽  
Author(s):  
Yuan Gu ◽  
Sizu Fu ◽  
Jiang Wu ◽  
Songyu Yu ◽  
Yuanlong Ni ◽  
...  

The experimental progress of laser equation of state (EOS) studies at Shanghai Institute of Laser Plasma (SILP) is discussed in this paper. With a unique focal system, the uniformity of the laser illumination on the target surface is improved and a laser-driven shock wave with good spatial planarity is obtained. With an inclined aluminum target plane, the stability of shock waves are studied, and the corresponding thickness range of the target of laser-driven shock waves propagating steadily are given. The shock adiabats of Cu, Fe, SiO2 are experimentally measured. The pressure in the material is heightened remarkably with the flyer increasing pressure, and the effect of the increasing pressure is observed. Also, the high-pressure shock wave is produced and recorded in the experimentation of indirect laser-driven shock waves with the hohlraum target.


2015 ◽  
Vol 91 (13) ◽  
Author(s):  
Agnès Dewaele ◽  
Vincent Stutzmann ◽  
Johann Bouchet ◽  
François Bottin ◽  
Florent Occelli ◽  
...  

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