A moving mesh interface tracking method for simulation of liquid-liquid systems

This manuscript presents a moving mesh interface tracking procedure, with a novel treatment for phase coupling. The new coupling strategy allows accurate predictions for the interface behaviour in a wide range of macroscopic properties with great potential to explore liquid-liquid systems. In this approach, governing equations are applied to each phase individually while the interface is represented by a zero-thickness surface that contemplates inter-phase jumps. These equations are described in an arbitrary Lagrangian-Eulerian finite volume framework. Computations consider the pressure-corrector PISO method. The new treatment for phase coupling incorporates the interfacial jump updates within the pressure/velocity calculations. Additionally, cell-centred values from both phases are considered when calculating convective and diffusive terms at the interface. The employment of GGI (Generalized Grid-Interface) interpolation provides conservative data mapping between surfaces for non-conformal meshes. The prediction capability of the new formulation is evaluated under different dominant effects governing interface motion. Simulated cases include gravity and capillary waves in a sloshing tank, three-dimensional drop oscillation for liquid-liquid systems and drop deformation due to shear flow. The numerical results show good agreement with analytical transient profiles of interface position. The procedure is able to successfully represent systems with similar macroscopic properties, i.e. density and viscosity ratios approaching unity, and a broad range of interfacial tensions. (C) 2017 Elsevier Inc. All rights reserved.