Modeling and computing transport in the subsurface is a difficult problem that requires good understanding of the relations among different processes at various different length and time scales, and their effective properties. Already at the pore scale, ranging from a few micrometers to millimeters, direct flow simulation in a detailed medium geometry assuming Stokes flow is extremely costly. N...

The permeability of reverse osmosis membranes is limited by the diffusive transport of water across a non-porous polyamide active layer. Alternatively, fabricating a microporous active layer capable of rejecting salt ions while allowing for water transport would increase the permeability while maintaining high salt rejection. Zeolites provide a model porous network which is capable of performin...

The constitutive relation that describes the amount of nonwetting ̄uid phase entrapment is critical to the modeling of multiphase ̄ow in porous media, but it has received insucient attention in the literature. We studied this relation using both experimental and modeling approaches: we used a nondestructive, X-ray monitored, long-column experiment that yielded a rich data set for two di€erent p...

Pore network models, in which the pore space is represented by a 3D network of interconnected pores and throats, are used extensively to compute important macroscopic transport properties including capillary pressure, relative permeability and residual saturation [2,6,12]. The predictive value of network models depends on the accuracy with which the network captures the complex geometric and to...

in saturated soils, heating induces thermal expansion of both grains and the pore fluid. lower thermal expansion coefficient of aggregates results in the increase of pore pressure and reduction of the effective stress besides subsequent volume changes due to the dissipation of pore pressure and heat transfer. dissipation of thermally induced pore pressure with time is a coupled thermo-hydro-mec...

We present a dynamic network model for modeling two-phase flow. We account for wetting layer flow, meniscus oscillation, and the dynamics of snapoff. Interfaces are tracked through pore elements using a modified Poiseuille equation for the equivalent hydraulic resistance of the fluids between the pore element centers. The model is used to investigate the effects of capillary number and viscosit...

Porous media are heterogeneous systems. The microstructures of the pore spaces influence their transport properties. A quantitative geometrical characterization of the pore space is crucial for accurate prediction of porous media transport. Thus, a 3D simulation of porous media was developed based on randomly packed glass beads. Unconsolidated porous media are reconstructed through Monte Carlo ...

Novel hydrogels based on hydroxyethyl starch modified with polyethylene glycol methacrylate (HES-P(EG)₆MA) were developed as delivery system for the controlled release of proteins. Since the drug release behavior is supposed to be related to the pore structure of the hydrogel network the pore sizes were determined by cryo-SEM, which is a mild technique for imaging on a nanometer scale. The resu...