Transport properties of fluids using new rough hard-sphere and molecular dynamics simulation

Abstract

We have studied transport properties, as well as the self-diffusion, viscosity and thermal conductivity of fluids by using new semi-theoretical model based on the rough hard-sphere (RHS) theory. In the present study, the proposed RHS is employed to model the transport properties of CH4, CCl4, C6H6, CHCl3, H2O, R134a, 2-EHB, PE and PS for temperatures ranging from 110 to 530 K and at pressures up to 1000 MPa. Parameters appeared in the new RHS model are taken from previously developed perturbed hard-trimer chain (PHTC) equation of state. From 174 experimental data points examined, the average absolute relative deviation AARD of predicted viscosities for CH4, H2O and R134a was found to be 6.59%. In the case of self-diffusion, the new RHS-based model correlated and predicted 139 experimental data points with AARD equal to 4.06%. The proposed RHS-based model has also been extended to predicted 228 experimental data points of thermal conductivity for CH4, H2O and R134a with AARD equal to 4.54%. In addition, molecular dynamics (MD) calculations were performed with the GROMACS simulation package and to investigate the thermophysical properties of fluids. The MD approach enabled us to calculate the density, viscosity, self-diffusion and thermal conductivity of CH4 and C6H6. The computed value of these properties agreement with experimental values. Finally, MD is applied to calculate density of binary water–alcohol mixtures including water–methanol and water–ethanol.