2-PHASE FLUID SUBJECTED TO TERRESTRIAL OR SPACE CONDITIONS - A LATTICE BOLTZMANN STUDY

A lattice Boltzmann model for two-phase fluids is used to find the equ ilibrium distribution of density and pressure across a vertical column under the action of terrestrial gravitational field. At low temperatu res and without surface tension, the density distribution has a discon tinuity point due to phase separation, while the pressure is always co ntinuous. At temperatures far above the critical point, the fluid colu mn behaves as an ideal gas and the well-known barometric formula is re covered. When surface tension is considered, this model gives also the correct behavior of a Van der Waals fluid placed in a tank subjected to terrestrial or space conditions in both cases, when the tank walls are wetted or not by the fluid.