Multiphase Chapter 3: Volume-of-Fluid (VOF) Method

The Volume-of-Fluid (VOF) method is a cornerstone of free-surface modeling in CFD. It tracks the motion of interfaces between immiscible fluids—like air and water—by solving a single set of flow equations and evolving a scalar volume fraction that marks how much of each phase fills a cell. This approach enables realistic simulation of sloshing, filling, jet breakup, and dam-break flows without deforming the mesh. In ANSYS Fluent, VOF offers multiple schemes for time integration and interface reconstruction, balancing sharpness, stability, and computational cost