A comparison of Lagrangian and Eulerian formulations for reactive transport modelling

摘要

Some ground water transport phenomena display sharp-edged fronts, specially when dealing with chemical reactions, such as oxidation processes. Eulerian formulations often fail to reproduce this kind of discontinuities due to numerical diffusion or instabilities. Lagrangian formulations overcome these difficulties, but introduce new ones, specially when dealing with transient flow and chemical reactions, each acting at a different rate. We propose a set of flexible lagrangian formulations that can override these issues. They are based on different approximations of the material derivative and the integration along the flow path. Those formulations have been implemented on a finite element code and some tests were performed in order to evaluate their performance