We assess the performance of an exponential integrator for advancing stiff, semidiscrete formulations of the unsaturated Richards equation in time. The scheme is of second order and explicit in nature but requires the action of the matrix function φ(A) = A−1(eA − I) on a suitability defined vector v at each time step. When the matrix A is large and sparse, φ(A)v can be approximated by Krylov su...

Abstract. Briggs (1897) deduced capillary flow from deviation of the equilibrium between capillarity and gravity. Richards (1931) raised to an unproven soil hydrological dogma. Attempts correct dogma led concepts non-equilibrium flow, macropore preferential during infiltration. Viscous film is proposed as alternative approach capillarity-driven unsaturated

the determination of soil wetting front which caused by emitters is one of the important issues in designing trickle irrigation system. in this study, a mathematical model introduced in order to study the position of soil wetting front during irrigation by point emitters in homegenious soil in unsteady condition. the model solves governing differential equation of unsaturated flow in cylindrica...

Continuous-flow, gas-phase selective oxidative dehydrogenation (ODH) of unsaturated long chain alcohols ( i.e. decen-1-ol isomers) to the corresponding aldehydes over an innovative, highly dispersed Cu-based catalyst supported ferrite.

A theory of cross-coupled flow equations in unsaturated soils is necessary to predict (1) electroosmotic flow with application to electroremediation and agriculture, (2) the electroseismic and the seismoelectric effects to develop new geophysical methods to characterize the vadose zone, and (3) the streaming current, which can be used to investigate remotely ground water flow in unsaturated con...

Glucose-dependent growth of the luxCDABE reporter bacterium Pseudomonas fluorescens HK44 was monitored noninvasively in quartz sand under unsaturated-flow conditions within a 45- by 56- by 1-cm two-dimensional light transmission chamber. The spatial and temporal development of growth were mapped daily over 7 days by quantifying salicylate-induced bioluminescence. A nonlinear model relating the ...

[1] In the paper ‘‘Fracture intersections as integrators for unsaturated flow’’ by Thomas R. Wood, Michael J. Nicholl, and Robert J. Glass (Geophys. Res. Lett., 29(24), 2191, 10.1029/2002GL015551, 2002) an error appears in paragraph [3] in the third sentence. The corrected sentence follows: At low flow, pulsed flow in the upper fracture was integrated by the intersection, and released into the ...

An integrated finite difference algorithm is presented for numerically solving the governing equation of saturated-unsaturated flow in deformable porous media. In recognition that stability of the explicit equation is a local phenomenon a mixed explicit-implicit procedure is used for marching in the time domain. In this scheme the explicit changes in potential are first computed for all element...

In this paper we investigate scale-dependent radial two-phase flow of liquid and gas in unsaturated porous media. First we present an equation of two-phase flow of liquid and gas in porous media in radial coordinates (ETPR) based on McWhorter’s equation in Cartesian coordinates. Then we present three analytical solutions for the ETPR: [1] an exact solution of ETPR in three dimensions for radial...