Prediction of Rheological Properties of Some Linear Hydrocarbons Using Molecular Dynamics Simulation

Present work aims at investigating rheological behavior of linear hydrocarbons by means of non-equilibrium molecular dynamics (NEMD) simulation. Simulation set up was a flow of hydrocarbon molecules confined between two molecular parallel plates. Through moving the top wall at constant velocity and investigation of relation of viscosity to shear stress, rheological behavior of hydrocarbons could be found out. Viscosity of hydrocarbons has been calculated by means of integration of Newtonian equations of motion and then shear stress tensor calculation and division of calculated shear stress by exerted shear rate. Our code verified with experimental data for light hydrocarbons (methane, ethane, propane and n-butane), reported results for a long chain hydrocarbon (C100H202), and results presented for some other hydrocarbons. According to the obtained results, it was found that with increasing hydrocarbon chain length, fluid viscosity will increase. Furthermore, the simulation results reveal that long chain hydrocarbons have a shear thinning non-Newtonian behavior with a power law relation.