Chapman-Enskog Theory

Chapman-Enskog theory provides a method to understand how gases behave when they are not at perfect equilibrium—such as in slow, controlled flows. It offers formulas to calculate properties like viscosity, thermal conductivity, and diffusion by considering molecules' movements and collisions. Essentially, it bridges the microscopic actions of individual molecules with the macroscopic behavior of gases, helping scientists and engineers predict how gases will flow and transfer heat under different conditions with good accuracy.