Direct Numerical Algorithm for Multiphase Flow with Free Surfaces and Interfaces.

This paper is to describe a new direct numerical procedure for solving general multiphase flow problems with many free surfaces and interfaces. Since conventional cell volume fraction approaches, such as SOLA-VOF, use the donor-acceptor procedure for the transport of fluid-segments, they cannot transport the interface slope with sufficient accuracy. In the present study, a new accurate algorithm for interface advection and its reconstruction, called MARS (Multi-interfaces Advection and Reconstruction Solver), was developed. It consists of the continuum surface force (CSF) model for surface tension and a new line-segment algorithm for capturing and connecting the interface between neighborhood computational cells. In order to show the potential of the MARS, some direct numerical simulation results for the formation and agglomeration of bubbles in a bubble column were presented as an example.