Implicit multigrid computations of unsteady multiphase flows in varying cross-sectional area channels

Abstract

Computations of two-dimensional multiphase flows involving complex geometries are presented. The numerical method is based on the front-tracking method in which one set of governing equations is written for the whole computational domain and different phases are treated as a single fluid with variable material properties. The front-tracking (FT) methodology is combined with a newly developed finite volume (FV) solver based on dual-time stepping, alternating direction implicit (ADI) multigrid method. First the FV solver is tested for a single phase flow in a constricted channel and then the FV/FT method is used to compute a free rising bubble in a straight channel and in channels with symmetric and antisymmetric constrictions. Finally, some preliminary results are also presented for many bubbles freely rising in the constricted channel.