A Lagrangian strategy for the numerical simulation of radionuclide transport problems

In this work a new algorithm for the computational implementation of the Forward Integral Tracking (FIT) method, originally introduced in Aquino et al. (2007a), is presented and applied to the numerical solution of radionuclide transport problems in saturated heterogeneous porous media.The FIT is a semi-discrete numerical method which is virtually free of numerical diffusion, does not use Riemann solvers, and is computationally very efficient. A new, locally conservative procedure for the inclusion and removal of tracked points that represent the particles of the radionuclide that are carried by the fluid flow is introduced.Numerical results which indicate numerical convergence of the new procedure under mesh refinement are discussed.