Approximation and Coalescence of Multiples Bubbles in Two-Phase Flows

Abstract

The present work aims at developing a new flexible computational framework based on modern programming language to simulate macro and microscale two-phase flows with complex interface dynamics to investigate approximation and coalescence of multiple bubbles. In this presentation the one-fluid interface tracking Finite Element (FE) method is used to solve the equations governing the motion of two immiscible incompressible fluids in the Arbitrary LagrangianEulerian framework (ALE), which allows mesh motion and adaptive refinement. For further details in the methodology, see [Anjos(2020), Anjos(2021)a, Anjos(2021)b, barbedo2024]. The interface between fluids is discretized explicitly with a set of interconnected nodes and used to accurately compute curvature using the Laplace-Beltrami operator. Due to its explicit representation, the interface connectivity must be updated during the onset of coalescence. Such a task may be accomplished by evaluating important approach parameters such as electrostatic and adhesion forces, as well as the use of lubricating theory to predict film drainage and bubble coalescence. Interesting results show strong interface deformations when several bubbles are present in the system. This is due to the improved mixing caused by the strong multidirectional motion of the fluid that appears in such a two-phase flow system. Notably, this combination of numerical methods has shown great promise in modeling complex two-phase systems with rich fluid dynamics. ACKNOWLEDGMENTS The research leading to these results received funding from the Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP) and the Research Support Foundation of the State of Rio de Janeiro (FAPERJ).