Determination of pressure-viscosity relation of 2,2,4-trimethylhexane by all-atom molecular dynamics simulations

Abstract

The Newtonian viscosity of 2,2,4-trimethylhexane at 293K is determined at pressures from 0.1MPa to 1000MPa. Non-equilibrium molecular dynamics simulations are performed using AIREBO-M, an all-atom potential for hydrocarbons especially parameterized for high pressures. The steady-state shear stress and viscosity are determined from simple shear simulations at rates between $10^7$ and $5\cdot 10^9{\text{s}}^{-1}$. At low pressures, simulation rates are low enough to reach the Newtonian regime. At high pressures, results are extrapolated to the Newtonian limit by fitting rate-dependent viscosities to Eyring theory. The resulting pressure dependent viscosity is typical of small molecules and fits to a common model are discussed.

14 pages, 4 figures, submitted to Fluid Phase Equilibria

Cited by in corpus (2)

• Uncertainties in the Transport Properties of Helium Gas at Cryogenic Temperatures Determined Using Molecular Dynamics Simulation
• Reliable Viscosity Calculation from High-Pressure Equilibrium Molecular Dynamics: Case Study of 2,2,4-Trimethylhexane