The interfacial region between two homogeneous phases contains matter in a distinct physical state; that is to say, matter in the interfacial state exhibits properties different from those matters in the gaseous, liquid, or solid states. As a result, as soon as interfaces are considered explicitly, new variables – for example, interfacial surface tension – enter into the classical thermodynamic description of equilibrium systems. Interfaces in equilibrium systems need not be considered explicitly unless the surface-to-volume ratio is large, because the contribution of interfacial free energy to the total free energy is usually small. However, interfacial effects on the dynamic behavior of flow systems can be profound, even when the proportion of matter in interfacial regions is extremely small. Furthermore, motion may originate in an interface in systems that are not in thermal or compositional equilibrium.
- Interfacial mass, momentum, energy, and species balances, interfacial resistance in vaporization and condensation, formation of and heat transfer through thin liquid films, and heat transfer in the thin-film region of an axially-grooved structure.
- Rayleigh-Taylor instability and Kelvin-Helmholtz Instability, and surface waves on liquid film flow.
Faghri, A., and Zhang, Y., 2006, Transport Phenomena in Multiphase Systems, Elsevier, Burlington, MA.