Oriol Lehmkuhl Barba

Conservative discretization of multiphase flow with high density ratios

The computation of multiphase flows presenting high density ratios, where the fluids involved are considered immiscible, are of great importance for fundamental physics and industrial applications; such as the study of liquid-gas interfaces, wave motion, simulation of bubbly flows and atomization, injection in diesel engines, chemical processes and others. This work presents and analyzes a collocated and staggered finite-volume mesh discretizations suitable for three-dimensional unstructured meshes, which are able to simulate immiscible multiphase flows with high density ratios. More over, these mesh schemes numerically conserve mass and momentum while minimize errors in the conservation of kinetic energy.

A finite-volume/level-set interface capturing method for unstructured grids: simulations of bubbles rising through viscous liquids

A numerical method is developed for simulating two-phase flows with moving inter-phase boundaries, which is integrated in a finite-volume framework on collocated unstructured grids of arbitrary element type. The location, geometry and the movement of the discontinuities are described by the conservative levelset method. The proposed algorithm is validated with experimental results of the buoyant rise of an isolated bubble. Then the method is applied to simulate the interaction between two bubbles during their buoyant rise. Finally, simulations for a set of bubbles with the same diameter initially placed in a random pattern in a periodic cylindrical duct are also carried out. In general, a good agreement is found between the current simulations and results reported in the literature.