the permeability and tortuosity of pore-scale two and three-dimensional random porous media were calculated using the lattice boltzmann method (lbm). effects of geometrical parameters of medium on permeability and tortuosity were investigated as well. two major models of random porous media were reconstructed by computerized tomography method: randomly distributed rectangular obstacles in a uni...

this paper presents a simple yet powerful original approach for approximating dispersivity in porous media. the key to this approach is both use of least-squares criterion and image processing technique. two dimensional transparent models, including horizontal and vertical configurations, under different combinations of grain sizes and pore velocities, experimented. concentration data were obta...

pore network modeling uses a network of pores connected by throats to model the void space of a porous medium and tries to predict its various characteristics during multiphase flow of various fluids. in most cases, a non-realistic regular lattice of pores is used to model the characteristics of a porous medium. although some methodologies for extracting geologically realistic irregular network...

Defect of the tendon sheath after tendon injury is a main reason for tendon adhesions, but it is a daunting challenge for the biomimetic substitute of the tendon sheath after injury due to its multi-layer membrane-like structure and complex biologic functions. In this study, a multi-layer membrane with celecoxib-loaded poly(l-lactic acid)-polyethylene glycol (PELA) electrospun fibrous membrane ...

Unsteady natural convection and heat transfer in a square cavity partially filled with porous media using a thermal non-equilibrium model is studied in this paper. The left vertical wall is maintained at a constant hot temperature Th and the right vertical wall is maintained at a constant cold temperature Tc, while the horizontal walls are adiabatic. The governing equations are obtained by appl...

This paper is concerned with plane wave propagation in multi-layer assemblies of rigid isotropic porous media inside impedance tubes. The focus placed on the inverse problem, i.e., retrieval intrinsic properties defining pore micro-structure each layer: porosity, mean size and standard deviation. Each layer considered isotropic. Such an problem can be ill-posed due to non-uniqueness solution. t...

Local thermal equilibrium is an often-used hypothesis when studying heat transfer in porous media. Examination of non-equilibrium phenomena shows that this hypothesis is usually not valid during rapid heating or cooling. The results from this theoretical study con®rm that local thermal equilibrium in a ̄uidized bed depends on the size of the layer, mean pore size, interstitial heat transfer coe...

this study has been investigated, the effects of three different polar polyacrylamides (anionic, cationic, and nonionic) on asphaltene deposition in porous media. all experiments were carried out in various dead oil flow rates (0.2, 0.1 and 0.02 cc/min) and different polymer concentrations (500, 2500, 4000 ppm). the results indicated that asphaltene precipitation was affected by the presence of...

the value of the permeability in fluid flow through porous media is important for process investigation. in low reynolds number, the classic darcy’s law is suitable for simulation of fluid flow. in this paper, an experimental study for evaluation of preformed fiber permeability has been done. also, the deviations from the classical darcy law by experimental and numerical simulation of the navie...

0017-9310/$ see front matter 2008 Elsevier Ltd. A doi:10.1016/j.ijheatmasstransfer.2008.04.025 * Corresponding author. Tel.: +1 951 827 2135; fax E-mail address: [email protected] (K. Vafai). Aorta–iliac bifurcation has been anatomically shown to be asymmetric. Also, statistical data reveal differences in the structural features of average male and female aorta–iliac bifurcation. In the presen...