Nicolae Suciu
contact: n.suciu@fz-juelich.de

Abstract:

For large scale transport problems in groundwater, the methods which track particles to simulate concentrations are successfully used, mainly when the aquifer properties are spatially heterogeneous. These methods are not concerned with numerical diffusion, occurring in finite difference/element schemes. The limitations are only due to large computation time and memory necessary to achieve statistically reliable results and accurate concentration fields. To overcome these computational limitations we developed a global random walk (GRW) al-gorithm. Unlike in the usual approach where the trajectory of each particle is simulated and stored, in GRW all the particles from a given grid node are scattered, at a given time, using a single numerical procedure, based on Bernoulli repartition, partial-deterministic, or determin-istic rules. We proved that for simple diffusion problems GRW converges to the finite difference scheme. For large scale transport problems in groundwater, GRW produces stable and statisti-cally reliable simulations which enable us to investigate the temporal behavior of the effective diffusion coefficients,

Authors:

N. Suciu (1), C. Vamos (1), H.Vereecken (2), J. Vanderborght (2), H. Hardelauf (2)
(1) Romanian Academy, T. Popoviciu Institute of Numerical Analysis, Cluj-Npoca, Romania
(2) Forschungszentrum Jülich, ICG-IV: Agrosphäre