Anti-Diffusion Modeling using a Non-local Censored Random Walk Scheme

Main Authors: Bagtzoglou, Amvrossios, Ababou, Rachid
Format: Proceeding
Terbitan: , 2006
Online Access: https://zenodo.org/record/3537326
Daftar Isi:
  • This paper builds on the Reversed Time Particle Tracking Method of Bagtzoglou (2003) and presents a novel methodology for time reversal in groundwater transport simulations. The basis of the proposed scheme for anti-diffusion is a continuous time, censored, nonlocal random walk capable of tracking groundwater solute concentration profiles over time. Our analysis leads to the conclusion that an adaptive (decreasing) time-stepping scheme is necessary in order to maintain a constant amount of anti-diffusion. More specifically, we study the interrelations between the following parameters: time-step evolution versus time or number of steps; variance evolution (decrease rate); and total time or total number of steps required to reach a fully anti-diffused solution. The approach is shown to be quite efficient (every 80 time steps an eight-fold reduction of the variance is attained) and is also asymptotically exact. Our method is applied to one-dimensional transport of conservative solutes in spatially invariant and variant groundwater flow fields with great success.
  • Presenters: name: Bagtzoglou, Amvrossios affiliation: Department of Civil & Environmental Engineering, University of Connecticut