要約

Numerical simulations of two dimensional flows of immiscible fluids separated by a sharp interface with or without surface tension are discussed. The flow field is computed by solving, on an unstructured fixed mesh, the full Navier-Stokes equations by the finite element method. The interface is tracked through the mesh by a pseudo-concentration based technique. In order to keep the fluid property fields sharp across the interface, a local mesh adaptation method has been developed. This procedure also provides an accurate and natural way to include surface tension effects. Both the Rayleigh-Taylor instability and the bubble motion simulations are presented. The numerical predictions compare very favourably with the theoretical results and/or the available experimental data.