Modeling of premixed gas combustion in porous media composed of Coarse-Sized particles: 1-D description with discrete solid phase

1996 ◽  
Vol 26 (2) ◽  
pp. 3383-3389 ◽  
Author(s):  
O.S. Rabinovich ◽  
A.V. Fefelov ◽  
N.V. Pavlyukevich
Keyword(s):  
Porous Media ◽  
Solid Phase ◽  
Gas Combustion

Comments on “Lamb's problem for fluid-saturated porous media”

1992 ◽  
Vol 82 (5) ◽  
pp. 2263-2273
Author(s):  
M. D. Sharma
Keyword(s):  
Porous Media ◽  
Boundary Conditions ◽  
Solid Phase ◽  
Elastic Solid ◽  
Porous Solid ◽  
Surface Boundary ◽  
Vertical Force ◽  
Saturated Porous Media ◽  
Concentrated Load ◽  
Lamb’S Problem

Abstract Philippacopoulos (1988) discusses axisymmetric wave propagation in a fluid-saturated porous solid half-space. The disturbance is considered to be produced by the concentrated load P0exp(iωt) acting vertically at the surface. Boundary conditions chosen imply that a vertical force acting on the surface of fluid-saturated porous solid exerts no pressure on the interstitial liquid. These boundary conditions do not seem appropriate. In the present study, the boundary conditions have been changed in order to satisfy the concept of porosity. These are also in accordance with those discussed by Deresiewicz and Skalak (1963) for the special case of interface between liquid and liquid-saturated porous media. Analytic expressions have been derived for the displacements at the surface. The limiting case of a dry elastic solid is also deduced. Effects of intergranular energy losses due to solid phase and of dissipation due to flow of pore fluid are exhibited on the displacements at the surface. Contrary to Philippacopoulos (1988), the displacements in saturated poroelastic solids are found to be larger than those in a dry elastic solid with same Lamb's moduli.

Thermal Analysis of Multijet Impingement Through Porous Media to Design a Confined Heat Management System

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Carlos Zing ◽  
Shadi Mahjoob
Keyword(s):  
Porous Media ◽  
High Efficiency ◽  
Solid Phase ◽  
Electronics Cooling ◽  
Jet Impingement ◽  
Fluid Phase ◽  
Volume Averaging ◽  
High Heat Flux ◽  
Base Temperature ◽  
Heat Management

Thermal management has a key role in the development of advanced electronic devices to keep the device temperature below a maximum operating temperature. Jet impingement and high conductive porous inserts can provide a high efficiency cooling and temperature control for a variety of applications including electronics cooling. In this work, advanced heat management devices are designed and numerically studied employing single and multijet impingement through porous-filled channels with inclined walls. The base of these porous-filled nonuniform heat exchanging channels will be in contact with the devices to be cooled; as such the base is subject to a high heat flux leaving the devices. The coolant enters the heat exchanging device through single or multijet impingement normal to the base, moves through the porous field and leaves through horizontal exit channels. For numerical modeling, local thermal nonequilibrium model in porous media is employed in which volume averaging over each of the solid and fluid phase results in two energy equations, one for solid phase and one for fluid phase. The cooling performance of more than 30 single and multijet impingement designs are analyzed and compared to achieve advantageous designs with low or uniform base temperature profiles and high thermal effectiveness. The effects of porosity value and employment of 5% titanium dioxide (TiO2) in water in multijet impingement cases are also investigated.

An Engineering Estimate for Plug-Flow Convection in Porous Media Discarding Fluid Conduction

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Nihad Dukhan
Keyword(s):  
Porous Media ◽  
Solid Phase ◽  
Plug Flow ◽  
Convection Heat Transfer ◽  
Constant Heat Flux ◽  
Heated Wall ◽  
Local Thermal Equilibrium ◽  
Equilibrium Equations ◽  
Non Local ◽  
Flow Through

Metal and graphite foam are relatively new types of porous materials characterized by having high-solid phase conductivities. In many cooling applications of these materials, including high-power electronics, low-conductivity fluids flow through them, e.g., air. A simple approximate engineering solution for the convection heat transfer inside a two-dimensional rectangular porous media subjected to constant heat flux on one side is presented. The conduction in the fluid is set to zero, and for simplicity, a plug flow is considered. As a result, the non-local-thermal equilibrium equations are significantly simplified and solved. The solid and fluid temperatures decay in what looks like an exponential fashion as the distance from the heated wall increases. The results are in good agreement with one more complex analytical solution in the literature, in the region far from the heated wall only.

Analysis of the consolidation problem of compressible porous media by a macroscopic variational continuum approach

2015 ◽  
Vol 22 (5) ◽  
pp. 952-968 ◽  
Author(s):  
Francesco Travascio ◽  
Shihab Asfour ◽  
Roberto Serpieri ◽  
Luciano Rosati
Keyword(s):  
Porous Media ◽  
Dimensionless Parameter ◽  
Solid Phase ◽  
Poisson Ratio ◽  
Fundamental Solutions ◽  
Dimensionless Numbers ◽  
Macroscopic Theory ◽  
Poroelastic Media ◽  
Stress Partitioning ◽  
Solid Stress

This study presents an analysis of the stress-partitioning mechanism for fluid saturated poroelastic media in the transition from drained (e.g. slow deformations) to undrained (e.g. fast deformation) flow conditions. The goal of this analysis is to derive fundamental solutions for the general consolidation problem and to show how Terzaghi’s law is recovered as the limit undrained flow condition is approached. The approach is based on a variational macroscopic theory of porous media (VMTPM). First, the linearized form of VMTPM is expressed in a u– p dimensionless form. Subsequently, the behavior of the poroelastic system is investigated as a function of governing dimensionless numbers for the case of a displacement controlled compression test. The analysis carried out in this study produced two crucial results. First, in the limit of undrained flow, it confirmed that the solutions of the consolidation problem recover Terzaghi’s law. Second, it was found that a dimensionless parameter ([Formula: see text]), which solely depends on mixture porosity and Poisson ratio of the solid phase, discriminates two diametrically opposed mechanic responses of the poroelastic system. More specifically, when [Formula: see text] is positive, the solid stress in the mixture first increases and then relaxes to an equilibrium value ( stress relaxation). In contrast, when [Formula: see text], the solid stress monotonically tenses up to reach the equilibrium value ( stress tension).

Wave propagation in heterogeneous porous media formulated in the frequency-space domain using a discontinuous Galerkin method

Geophysics ◽  
2011 ◽  
Vol 76 (4) ◽  
pp. N13-N28 ◽  
Author(s):  
Bastien Dupuy ◽  
Louis De Barros ◽  
Stephane Garambois ◽  
Jean Virieux
Keyword(s):  
Porous Media ◽  
Wave Propagation ◽  
Galerkin Method ◽  
Frequency Domain ◽  
Discontinuous Galerkin ◽  
Discontinuous Galerkin Method ◽  
Solid Phase ◽  
Numerical Models ◽  
Fluid Phase ◽  
Heterogeneous Porous Media

Biphasic media with a dynamic interaction between fluid and solid phases must be taken into account to accurately describe seismic wave amplitudes in subsurface and reservoir geophysical applications. Consequently, the modeling of the wave propagation in heteregeneous porous media, which includes the frequency-dependent phenomena of the fluid-solid interaction, is considered for 2D geometries. From the Biot-Gassmann theory, we have deduced the discrete linear system in the frequency domain for a discontinuous finite-element method, known as the nodal discontinuous Galerkin method. Solving this system in the frequency domain allows accurate modeling of the Biot wave in the diffusive/propagative regimes, enhancing the importance of frequency effects. Because we had to consider finite numerical models, we implemented perfectly matched layer techniques. We found that waves are efficiently absorbed at the model boundaries, and that the discretization of the medium should follow the same rules as in the elastodynamic case, that is, 10 grids per minimum wavelength for a P0 interpolation order. The grid spreading of the sources, which could be stresses or forces applied on either the solid phase or the fluid phase, did not show any additional difficulties compared to the elastic problem. For a flat interface separating two media, we compared the numerical solution and a semianalytic solution obtained by a reflectivity method in the three regimes where the Biot wave is propagative, diffusive/propagative, and diffusive. In all cases, fluid-solid interactions were reconstructed accurately, proving that attenuation and dispersion of the waves were correctly accounted for. In addition to this validation in layered media, we have explored the capacities of modeling complex wave propagation in a laterally heterogeneous porous medium related to steam injection in a sand reservoir and the seismic response associated to a fluid substitution.

scholarly journals Active wall through a porous media foam type: flow and transfer characterization

2020 ◽  
Vol 330 ◽  
pp. 01052
Author(s):  
Rafael Deptulski ◽  
Gisele Vieira ◽  
Rachid Bennacer
Keyword(s):  
Thermal Conductivity ◽  
Porous Media ◽  
Solid Phase ◽  
Cross Flow ◽  
Structured Media ◽  
Medium Porosity ◽  
Flow Through ◽  
Thermodynamic Coupling ◽  
Volume Method ◽  
Solid Phase Composition

Despite the efforts to develop new solutions to achieve the objectives of positive buildings in energy, a few studies in this area has been performed using a porous media foam type. The aim of this paper is to present the behaviour transfers of flow through a multi-structured porous media and to achieve the influence of the porosity and the thermal conductivity properties of the skeletal phase, and the interaction with a cross flow in order to get the equivalent of a perfect insulator. Therefore, in a specially made device, a finite volume method was applied to study a flow through a porous media foam-type, which was simulated to characterize the properties of the equivalent medium in terms of permeability and thermal conductivity. The analysis demonstrates that the solid phase composition and the medium porosity, as well as the distribution of pore size, are preponderant characteristics to constitute a foam structured media. Furthermore, the thermal boundary layer given by a forced convection through the porous medium has demonstrated the important influence of the flow phenomenon in a thermodynamic coupling. Lastly, three optimum configurations for the construction envisaging a balance of depleted thermal and dynamic powers for a relative conductivity *=10 were found between the velocity 2 10-3 (m/s) and 4 10-3 (m/s).

Sign in / Sign up

Export Citation Format

Share Document