High Pressure and Temperature Effects on the Viscosity, Density, and Bulk Modulus of Four Liquid Lubricants.

High-Pressure Densities of Industrial Lubricants and Complex Oils Predicted by the Fluctuation Theory-Based Equation of State

“…For example, for the paraffinic lubricants at the highest temperature, 491.48 K, and pressure, 1013.63 MPa, the model underpredicted the densities by a max RAD of 2.64%. Similar predictions are made in Figure c,d with the high-pressure studies by Hopkins and Hogan , in the 1970s, where they measured classified lubricants. The density of MLO 75-112 is accurately predicted to an AAD of 0.46%, while the ATL 4102 has a larger deviation.…”

“…FT-EoS predictions (solid lines) to their high-pressure high-temperature experimental data from AMSE technical reports: (a) sample 53, Dow Corning 550 silicon oil; (b) sample 33, Parafinic 2500 oil {◇ (273.15 K), △ (298.15 K), □ (310.93 K), × (372.04 K), and ∗ (491.48 K)}. From Hogan and Hopkins: , (c) MLO 75-122 and (d) ATL 4102 {◇ (310.95 K), △ (372.05 K), and □ (422.05 K)}.…”

“…The density, ρ, or specific volumes, v , and by extension isobaric thermal expansivity, α p , and isothermal compressibility, κ T , of lubrication oils are interesting from both practical and scientific perspectives and have been since the 1950s when the compilation of density and viscosity data from the American Society of Mechanical Engineers was produced. To the authors’ best knowledge, experimental densities can be found for lubricants which have been measured up to pressures of 1 GPa and temperatures of 533 K. , With respect to the experimental methods of the time, the density data are necessary for calculating viscosities with increasing temperature and pressure. Instrumentation for measuring fluid expansion with changing pressures have included methods such as vibrating tube densitometers, − specially designed piezometers, , and flexible bellows. − The practical application of these density properties and their related thermal properties are needed to produce heat-transfer models for engine coolants and to maximize the transmitting pressure of hydraulic fluids.…”

“…To the authors’ best knowledge, experimental densities can be found for lubricants which have been measured up to pressures of 1 GPa and temperatures of 533 K. , With respect to the experimental methods of the time, the density data are necessary for calculating viscosities with increasing temperature and pressure. Instrumentation for measuring fluid expansion with changing pressures have included methods such as vibrating tube densitometers, − specially designed piezometers, , and flexible bellows. − The practical application of these density properties and their related thermal properties are needed to produce heat-transfer models for engine coolants and to maximize the transmitting pressure of hydraulic fluids. Other temperature-dependent properties that are derived using densities include the thermal pressure coefficient, γ; the internal pressure, p int ; the difference between specific isobaric heat capacity, c p ; specific isochoric heat capacity, c v ; thermal diffusivity, λ; dynamic viscosity, η; and Reynolds number, Re.…”