Analysis of Traction Properties of Fluids using Molecular Dynamics Simulations

摘要

Non-equilibrium all-atom MD simulations are used to study the traction properties of hydrocarbon fluids. A fluid layer is confined between two solid Fe plates under the constant normal force of 1.0 GPa. Traction behaviors of 10 hydrocarbon fluids are simulated on a sufficiently large film thickness of 6.7 nm, and succeeded in reproducing the order of the experimental traction coefficients. The dynamic mechanism of the momentum transfer on layers of fluid molecules are analyzed focusing on the intermolecular interactions and intramolecular interactions. Mechanisms are obtained in the high traction molecules of cyclohexane and dumbbell like molecules (dicyclohexyl, dicyclohexylmethyl and santotrac 50). In dumbbell like molecules, alicyclic rings, which distribute across the low ordered molecular layers, behave as a stiff bulky mass, and momentum transfers to the end of the molecular axis. The traction mechanisms often hydrocarbon fluids are also obtained during the course of the analysis.