Molecular Dynamics Study for Vaporization of Hydrocarbon Fuels Used for Internal Combustion Engine

Abstract

Isooctane and normal-dodecane are ones of hydrocarbon fuel for an internal combustion engine. Unsteady motion of molecules at liquid-vapor interface and heat conduction phenomenon of nano-sized liquid in air are simulated by molecular dynamics method. Molecular dynamics method is to solute numerically classical equation of motion of atoms as N-body problems. Macroscopic and microscopic physical quantities are obtained from time series data of position and velocity of atoms by using statistical mechanics. Vaporization rate of isooctane was faster than that of normal-dodecane at 600K. Vaporization of hydrocarbon causes decline of internal energy of the simulation system because of latent heat. At NVT ensemble condition, however, the internal energy is supplied by temperature keeping method.