The Molecular Model

Abstract

Abstract A gas flow may be modelled at either the macroscopic or the microscopic level. The macroscopic model regards the gas as a continuous medium and the description is in terms of the spatial and temporal variations of the familiar flow properties such as the velocity, density, pressure, and temperature. The Navier-Stokes equations provide the conventional mathematical model of a gas as a continuum. The macroscopic properties are the dependant variables in these equations, while the independent variables are the spatial coordinates and time.