A class of boundary value problems for nonlinear diiusion equations is studied. Using singular perturbation theory and matched asymptotic expansions, the author analyzes the interactions of compact-support solutions of the porous media equation with xed boundaries and with other solutions. The boundary layer analysis yields results on how \stopping" and \merging" disturbances at the interface p...

In this paper, the acoustical treatment of double-panel structures lined with poroelatic materials is predicted using analytical method in order to study the effective usage of the various boundary conditions of porous layer and to identify the effective parameters on the transmission loss of the multilayer systems. Therefore, inertia and viscous coupling along with thermal and elastic coupling...

An analysis of entropy generation in an MHD boundary layer flow of a viscous incompressible electrically conducting fluid past an inclined flat plate embedded in a porous media in a rotating system with Hall currents has been presented. The governing equations describing the flow have been solved analytically. The velocity field, induced magnetic field, shear stress and bulk temperature in the ...

We study the asymptotic behavior of the infinite Darcy-Prandtl number DarcyBrinkman-Boussinesq system for convection in porous media at small Brinkman-Darcy number. The existence of a boundary layer with thickness proportional to the square root of the BrinkmanDarcy number for the velocity field is established in both the L∞(H1) norm (2 and 3 d) and the L∞(L∞) norm (2d only). This improves an e...

Crystalline powders self-assembled from interactive discrete molecules reversibly transformed from a porous structure to a 2D one with a nanometer-thick H2O layer by hydration/dehydration. Multi-point weak intermolecular interactions contributed to maintenance of each phase. This structure transformation induced a humidity-dependent ion conductivity change from insulator to 3.4 × 10(-3) S cm(-1).

The work presented in this paper concerns the behaviour of porous media when exposed to a normal incidence sound field. A propagating wave model based on lumped parameter concepts of acoustic mass, stiffness and damping is used to investigate the absorption phenomena due to the wave propagation in the layer(s) and interference effects due to the wave reflection–transmission at the interfaces of...

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...

The problems of steady film condensation on a vertical surface embedded in a thin porous medium with anisotropic permeability filled with pure saturated vapour are studied analytically by using the Brinkman-Darcy flow model. The principal axes of anisotropic permeability are oriented in a direction that non-coincident with the gravity force. On the basis of the flow permeability tensor due to t...

We developed a novel method for fabrication of glass micromodels with varying depth (2.5-D) with no additional complexity over the 2-D micromodels' fabrication. Compared to a 2-D micromodel, the 2.5-D micromodel can better represent the 3-D features of multi-phase flow in real porous media, as demonstrated in this paper with three different examples. Physically realistic capillary snap-off and ...

A numerical approach for approximating statistical moments of hydraulic heads of variably saturated flows in multi-dimensional porous media is developed. The approximation relies on a first-order Taylor series expansion of a finite element flow model and an adjoint state numerical method for variably saturated flows to evaluate sensitivities. This approach can be employed to analyze uncertainti...