Autor: RODRIGO ALFONSO PEREZ

MODPATH-RW: A Random Walk Particle Code for Solute Transport in Heterogeneous Aquifers.

Abstract:

Random Walk Particle Tracking (RWPT) is a mass-particle method that offers several advantages for simulating solute transport in heterogeneous geological systems. The formulation is a discrete solution to the advection-dispersion equation, leading to results not influenced by grid-related numerical dispersion, which has a negative impact on the concentrations obtained from classical grid-based models. This seminar presents a solute transport code implementing RWPT by extension of the well-known particle tracking model MODPATH, which provides the base infrastructure for achieving a versatile code seamlessly integrated with industry-standard groundwater flow models based on MODFLOW. The implementation is achieved thanks to a method that determines the exact cell-exit position of a particle undergoing simultaneous advection and dispersion, allowing for the sequential transfer of particles between flow model cells. MODPATH-RW is compatible with rectangular unstructured grids and integrates a module for the smoothed reconstruction of concentrations. The program incorporates parallel processing of particles using the OpenMP library. Numerical test cases involving different applications in hydrogeology benchmark the new RWPT model with well-known transport codes.

Webinar