IsoAdvector: Geometric VOF on General Meshes

In a recent publication, we presented a novel geometric VOF interface advection algorithm, denoted isoAdvector (Roenby et al. in R Soc Open Sci 3:160405 2016, [1]). The OpenFOAM ® implementation of the method was publicly released to allow for more accurate and efficient two-phase flow simulations in OpenFOAM ® (Roenby in isoAdvector www.github.com/isoadvector, [2]).

In the present paper, we give a brief outline of the isoAdvector method and test it with two pure advection cases. We show how to modify interFoam so as to use isoAdvector as an alternative to the currently implemented MULES limited interface compression method. The properties of the new solver are tested with two simple interfacial flow cases, namely the damBreak case and a steady stream function wave.

We find that the new solver is superior at keeping the interface sharp, but also that the sharper interface exacerbates the well-known spurious velocities in the air phase close to an air–water interface. To fully benefit from the accuracy of isoAdvector, there is a need to modify the pressure–velocity coupling algorithm of interFoam, so it more consistently takes into account the jump in fluid density at the interface.

In our future research, we aim to solve this problem by exploiting the subcell information provided by isoAdvector.