An adaptive time discretization of the classical and the dual porosity model of Richards' equation
Michal Kuraz, Petr Mayer, Matej Leps, Dagmar Trpkosova
Abstract:
This paper presents a numerical solution to the equations describing Darcian flow in a variably
saturated porous medium - a classical Richards' equation model Richards (1931) [1]
and an extension of it that approximates the flow in media with preferential paths - a dual
porosity model Gerke and van Genuchten (1993) [8]. A numerical solver to this problem,
the DRUtES computer program, was developed and released during our investigation. A
new technique which maintains an adaptive time step, defined here as the Retention Curve
Zone Approach, was constructed and tested. The aim was to limit the error of a linear approximation
to the time derivative part. Finally, parameter identification was performed
in order to compare the behavior of the dual porosity model with data obtained from a
non-homogenized fracture and matrix flow simulation experiment.