An ALE-FEM Method for Axisymmetric Two-Phase Flows

Abstract

The present work aims at developing a computational framework to simulate macro and microscale two-phase flows in axisymmetric coordinates. An important application is the microchannels that will be used for the cooling of next generation micro-electronics and flows in biological systems. Several flow regimes can be found in those channels such as annular flow, slug flow with small and large bubbles and single bubble flows. All regimes are characterised by a thin interface seprating fluids. Therefore, an accurate method capable of capturing the wall/interface dynamics is strictly required. In this article an interface tracking Finite Element Method (FEM) is used to solve the equations governing the motion of two in-miscible incompressible fluids. This method describes the interface between the different fluids by a layer of zero thickness, which makes it highly accurated. At the scale of interest, surface tension plays an important role and is thus considered in the equations. An in-house code, previously implemented by Anjos (2012); Anjos et al. (2014b,a), is further developed and presently extended first to better model microchannel flows. This paper will present tests and validations of the current axisymmetric code in comparison with large used benchmarks.