  We study the governing equations for the motion of the fluid particles near
air-water interface from an energetic point of view. Since evaporation and
condensation phenomena occur at the interface, we have to consider phase
transition. This paper applies an energetic variational approach to derive
multiphase flow systems with phase transition, where a multiphase flow means
compressible and incompressible two-phase flow. We also research the
conservation and energy laws of our system. The key ideas of deriving our
systems are to acknowledge the existence of the interface and to apply an
energetic variational approach. More precisely, we assume that both the
coefficient of surface tension and the density of the interface are constants,
and we apply an energetic variational approach to look for the dominant
equations for the densities of our multiphase flow systems with phase
transition. As applications, we can derive the usual Euler and Navier-Stokes
systems, or a two-phase flow system with surface tension by our methods.
