We simulate wave propagation in a partially saturated porous medium, where the novel feature is the presence of a second slow wave due to capillary forces. The pores are filled with a wetting fluid and a non-wetting fluid, and the model, based on a Biot-type three-phase theory, predicts three compressional waves and one shear wave. Moreover, the theory models the realistic attenuation levels ob...

Self-potential (SP) data are of interest to vadose zone hydrology because of their direct sensitivity to water flow and ionic transport. There is unfortunately little consensus in the literature about how to best model SP data under partially saturated conditions and different approaches (often supported by one laboratory data set alone) have been proposed. We argue herein that this lack of agr...

Liquid distributions in unsaturated porous media under different gravitational accelerations and corresponding macroscopic gaseous diffusion coefficients were investigated to enhance understanding of plant growth conditions in microgravity. We used a single-component, multiphase lattice Boltzmann code to simulate liquid configurations in two-dimensional porous media at varying water contents fo...

Direct measurement of through-plane thermal conductivity of partially saturated fuel cell diffusion media. " Master's Thesis, I am submitting herewith a thesis written by Guoqing Xu entitled "Direct measurement of through-plane thermal conductivity of partially saturated fuel cell diffusion media." I have examined the final electronic copy of this thesis for form and content and recommend that ...

[1] Contaminant migration through the vadose zone may be influenced by the presence of mineral colloids that are mobilized during infiltration events. In this work, we report model calculations and experimental data on the role of pore water ionic strength in the transport of silica colloids through water-saturated and unsaturated porous media. The transport model solves the advection-dispersio...

A recently published constitutive model for drying of a partially saturated porous material is extended to take into account finite air (gas) pressure as well as finite external load, variables that are absent during simple drying under atmospheric conditions. We further use the result to derive a general form of effective stress in a partially saturated material. The proposed framework overcom...

Differential effective medium (DEM) theory is applied here to the problem of modeling physical properties of poroelastic media that are partially saturated with liquid. Typical fluid saturants are air and water, or gas and oil. If the liquid and gas saturants are homogeneously mixed, then we say the medium is partially saturated. If the liquid and gas saturants are poorly mixed, so each constit...

The paper proposes a combined application of composite theory and Powers’ model for microstructural development for the estimation of the diffusion coefficient as a function of the moisture content of a defect-free cementitious material. Measurements of chloride diffusion in mortar samples (440 kg/m rapid-hardening Portland cement, w/c = 0.5, maturity minimum 6 months) stored at 65% and 85% RH,...