Simulations of droplet relaxation using volume of fluid method (VOF)

In this research, the volume of fluid (VOF) method, which is used for simulating two-phase flows, is applied and the surface tension force is implemented to simulate thecircular and square droplet behavior in static fluid. Fluid flow is assumed to be incompressible, unsteady and two- dimensional. Surface tension force is modeled withcontinuum surface stress (CSS) model. The developed VOF code is verified by two test cases. namely pressure jump over a droplet interface and oscillating droplet test.The former test case showed that the calculated pressure jump converges to the analytical solution by refining the grid. Also. simulation results show that the density ratiodoes not affect the magnitude of pressure jump. In the oscillating droplet test case, the numerical dissipation eventually damps the oscillation and the drop finallyapproaches an equilibrium circular shape. The numerical results of the present work are in good agreetnent with the analytical solutions. which shows the capability of theVOF method to simulate the gas-liquid two-phase flows.

Keywords:

Two-phase flow. VOF method. Surface tension , Numerical simulations