Hello ! Can someone give me the differences between Volume Of Fluid (VOF) method and phase field method ? In each case, one defines a scalar for knowing in which phase the grid cell is, and in each case, the grid is fixed. So I don't really understant what's different with the phase field method.

Thanks in advance !

First of all, the governing equations of the scalar for VOF and phase field method are different.

One is advected by velocity and after that we reconstruct volume fraction.

The other is governed by Cahn-Hilliard equation.

Most of cases, the volume fraction changes across interface within three grid points in VOF, but in the phase field method the scalar changes 5~8 grid points and across interface the phase field changes smoothly.

You can check my website for the movies from the phase field method for the multi-component system.

http://math.uci.edu/~jskim/simulations.html

Hi,

Can someone explain the difference between the G-equation used in combustion and a transport equation for the reaction progress variable, for example. I know that they have different forms, but they are looking for the same answer (i.e, an accurate description of the flame front) so I am wondering what advantages and disadvantages of them are?