Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

The pressure dependence of viscosity for 2,2,4 trimethylhexane to 1 GPa along the 20 C isotherm

Bair, Scott
Fluid Phase Equilib. 2019, 488, 9-12
ABSTRACT
A fundamental requirement for film generation in elastohydrodynamic lubrication (EHL) is that the viscosity of the liquid increase strongly with increase in pressure. The pressure dependence of viscosity influences both the thickness of the film separating the machine elements and the friction force which opposes their relative motion. Oddly, accurate descriptions of the piezoviscous effect were not employed in the study of EHL until about ten years ago. Advances in understanding film formation and friction are now proceeding quickly and the demand from industry for this information is growing. Molecular dynamics simulations have the promise of generating pressure-viscosity data for liquids which have not yet been synthesized but only if the accuracy of the method can be validated.
Compounds
# Formula Name
1 C9H20 2,2,4-trimethylhexane
2 C8H18 2,2,4-trimethylpentane
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Viscosity, Pa*s ; Liquid
  • Pressure, kPa; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Capillary tube (Ostwald; Ubbelohde) method
  • 14
  • POMD
  • 2
  • Viscosity, Pa*s ; Liquid
  • Pressure, kPa; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Capillary tube (Ostwald; Ubbelohde) method
  • 12