VOF method

The volume-of-fluid method (VOF method) is one of the standard methods for calculating two-phase flows in computational fluid dynamics.  The VOF method uses finite volume discretization, i.e. the model is divided into three-dimensional volume elements (calculation cell), as is the case in common CFD simulations. Within the calculation cell a new variable C is stored, which represents the volume fraction of a phase within the cell. The value can be between 0 and 1. The physical properties such as density or viscosity are derived from the distribution of the phases. In cells containing both fluids, these values are averaged. The values are then used to calculate a new velocity field using the Navier-Stokes equations. The VOF method can take into account additional physical properties. These include surface tension, heat transport, buoyancy effects, and phase changes.