Thermal Dispersion in High-Conductivity Porous Media

2012 ◽  
pp. 153-180 ◽  
Author(s):  
Christopher T. DeGroot ◽  
Anthony G. Straatman
Keyword(s):  
Porous Media ◽  
High Conductivity ◽  
Thermal Dispersion

A Comparison of Thermal Dispersion Behaviour in High-Conductivity Porous Media of Various Pore Geometries

2012 ◽  
Vol 326-328 ◽  
pp. 307-312
Author(s):  
Christopher T. DeGroot ◽  
Anthony G. Straatman
Keyword(s):  
Porous Media ◽  
Three Dimensional ◽  
High Conductivity ◽  
Circular Cylinders ◽  
Pore Geometry ◽  
Thermal Dispersion ◽  
Equilibrium Conditions ◽  
Solid Constituent ◽  
Prandtl Numbers ◽  
Graphite Foam

The effect of pore geometry on the axial thermal dispersion conductivity for high-conductivity porous media under general thermal non-equilibrium conditions is studied numerically. Pore geometries including arrays of inline square and circular cylinders, staggered circular cylinders, and a three-dimensional idealization of a graphite foam pore geometry are used to study the effects of the solid constituent shape and arrangement, as well as the effect of a relatively complex three-dimensional pore structure. Results indicate that in general, the dispersion conductivity cannot be considered a simple function of the Péclet number due to the effects of inertia, which cause the dispersion behaviour to depend on both the Reynolds and Prandtl numbers. On the basis of the current results, it is recommended that the influences of the Reynolds and Prandtl numbers be considered separately when generating models for the dispersion conductivity.

Investigation of thermal dispersion and intra-pore turbulent heat flux in porous media

2020 ◽  
Vol 81 ◽  
pp. 108523
Author(s):  
Nima Fallah Jouybari ◽  
T. Staffan Lundström ◽  
J.Gunnar I. Hellström
Keyword(s):  
Heat Flux ◽  
Porous Media ◽  
Turbulent Heat Flux ◽  
Turbulent Heat ◽  
Thermal Dispersion

scholarly journals FRACTAL DIMENSIONS FOR UNSATURATED POROUS MEDIA

Fractals ◽  
2004 ◽  
Vol 12 (01) ◽  
pp. 17-22 ◽  
Author(s):  
BOMING YU ◽  
JIANHUA LI
Keyword(s):  
Porous Media ◽  
Transport Properties ◽  
Fractal Theory ◽  
Fractal Dimensions ◽  
Thermal Dispersion ◽  
Unsaturated Porous Media ◽  
Empirical Constant ◽  
Pore Sizes ◽  
Analytical Expressions

The analytical expressions of the fractal dimensions for wetting and non-wetting phases for unsaturated porous media are derived and are found to be a function of porosity, maximum and minimum pore sizes as well as saturation. There is no empirical constant in the proposed fractal dimensions. It is also found that the fractal dimensions increase with porosity of a medium and are meaningful only in a certain range of saturation Sw, i.e. Sw>S min for wetting phase and Sw<S max for non-wetting phase at a given porosity, based on real porous media for requirements from both fractal theory and experimental observations. The present analysis of the fractal dimensions is verified to be consistent with the existing experimental observations and it makes possible to analyze the transport properties such as permeability, thermal dispersion in unsaturated porous media by fractal theory and technique.

Non-Darcy Mixed Convection With Thermal Dispersion in a Saturated Porous Medium

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
V. V. Sobha ◽  
R. Y. Vasudeva ◽  
K. Ramakrishna ◽  
K. Hema Latha
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Porous Media ◽  
Nusselt Number ◽  
Mixed Convection ◽  
Vertical Plate ◽  
Saturated Porous Medium ◽  
Thermal Dispersion ◽  
Convection In Porous Media ◽  
Infinite Vertical Plate

Thermal dispersion due to local flows is significant in heat transfer with forced convection in porous media. The effects of parametrized melting (M), thermal dispersion (D), inertia (F), and mixed convection (Ra/Pe) on the velocity distribution, temperature, and Nusselt number on non-Darcy, mixed convective heat transfer from an infinite vertical plate embedded in a saturated porous medium are examined. It is observed that the Nusselt number decreases with increase in melting parameter and increases with increase in thermal dispersion.

Analytical Investigation of the Effect of Thermal Dispersion on Forced Convection in Heterogeneous Porous Media

2001 ◽  
Author(s):  
A. V. Kuznetsov
Keyword(s):  
Porous Media ◽  
Nusselt Number ◽  
Forced Convection ◽  
Boundary Layers ◽  
Solid Wall ◽  
Reynolds Numbers ◽  
Analytical Investigation ◽  
Heterogeneous Porous Media ◽  
Thermal Dispersion ◽  
Energy Equations

Abstract This paper presents a new analytical solution of a problem of forced convection in a heterogeneous channel filled with two different layers of isotropic porous media. The Brinkman-Forchheimer-extended Darcy equation is utilized to describe the fluid flow in the porous layers, and the effect of transverse thermal dispersion is accounted for in the energy equations. Three momentum boundary layers are identified in the channel: a boundary layer at the solid wall and two boundary layers at the interface between the porous media. The dependence of the Nusselt number on the Darcy numbers, Forchheimer coefficients, and particle Reynolds numbers in different parts of the channel is investigated. This study demonstrates that thermal dispersion has a strong effect on the Nusselt number in the channel for large particle Reynolds numbers.

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