סמינר מחלקתי Alvaro Coutinho

School of Mechanical Engineering Seminar
Wednesday, March 11, 2015 at 15:00
Wolfson Building of Mechanical Engineering, Room 206

Interface Capturing Finite Element Strategies for Fluids

Alvaro L.G.A. Coutinho

High Performance Computing Center and Department of Civil Engineering
COPPE/Federal University of Rio de Janeiro
PO Box 68506, Rio de Janeiro, RJ 21945-970, Brazil
 

The hydrodynamics of fluid mixtures is receiving more and more attention in many science and engineering applications. Within the techniques for dealing with front displacements and moving boundaries between fluids with different density and viscosity, interface capturing are very successful. Among then we may find sharp interface methods such as Volume-of-Fluid and Level Sets. Phase fields are a class of models in which a diffusive transition region is taken into account instead of a steep interface. In this talk, we review general interface capturing methods and their finite element formulation on a pure Eulerian framework. Examples of interest in engineering and science are given. We explore here particular features of the classic Allen–Cahn (AC) phase field model. We introduce a modified AC model exploring its similarities with residual-based discontinuity- capturing schemes, making the phase field equation dependent on its own residual. In this case, we solve the coupling between the incompressible viscous fluid flow and the phase field advective–diffusive–reactive transport to simulate the main processes in interface tension and buoyancy-driven problems. Bubble interaction problems are studied to show the effectiveness of the new AC model. Results suggest that the proposed model is less parameter dependent and possess better conservation properties.