Measurement and Numerical Simulation of Hysteretic Flow in a Heterogeneous Porous Medium

Abstract

A finite difference solution of the Richards equation was tested experimentally for hysteretic flow in a nonuniform medium. The space‐dependent hydraulic properties (water content‐pressure head and hydraulic conductivity‐water content) were determined experimentally on a laboratory column of sand and were represented in the numerical model by empirical equations.Boundary conditions resulting in hysteretic flow were applied to both the experimental column and the numerical model and the resulting water content and pressure head profiles were compared. Agreement was excellent between the measured and computed results. An additional simulation, in which the medium was considered to be nonhysteretic, gave good agreement between the measured and computed pressure head values but resulted in substantial error in the computed water content values.

Numerical modelling of moisture transfers with hysteresis within cementitious materials: Verification and investigation of the effects of repeated wetting–drying boundary conditions

“…Inspired by the work of Gillham et al [48], two hysteresis indexes U and V are introduced to deal with each issue. These two indexes have to be assigned to each node during the numerical calculations.…”

The effect of hysteresis on three‐dimensional transient water flow during surface trickle irrigation

“…Hysteresis can significantly influence water flow in variably saturated porous media (Vachaud and Thony, 1971;Gillham et al, 1979;Russo et al, 1989). Hysteresis refers to the non-unique relationship between the pressure head, H, and the water content, Q, in the soil water characteristic curve (SWCC).…”

Soil Hydraulic Properties

“…Ignoring hysteresis in the K-θ -h relations may be partly based on an assumption that its effects are negligible, partly on the absence of a well-validated hysteretic model that is easy to calibrate (Lenhard et al, 1991), and partly on the difficulties of performing measurement experiments that are suitable to identify parameters of hysteresis models. Neglecting hysteresis leads to significant errors in the water redistribution under transient boundary conditions (Dane and Wierenga, 1975;Gillham et al, 1979, Hoa et al, 1977Viaene et al, 1994;Lehmann et al, 1999;Si and Kachanoski, 2000). Russo et al (1989) and Mitchell and Mayer (1998) investigated the influence of hysteresis on solute transport and found that the magnitude of the deviations between hysteretic and nonhysteretic simulations was not a simple function of single parameters, but rather depended on the combined values of many or all of the hydraulic parameters.…”