Convective heat transfer in vertical cylindrical annuli filled with a porous medium

Havstad, Mark; Burns, Pat

doi:10.1016/0017-9310(82)90155-7

Cited by 59 publications

(23 citation statements)

References 12 publications

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“…For an annuli whose inner wall is heated at constant temperature and outer wall is isothermally cooled, the top and bottom being insulated (82,83,84,85), heat transfer results have been obtained for a wide range 119 of Rayleigh numbers, aspect (height to gap width) ratios, A, and radius ratios, C. Results obtained through a numerical study show that the curvature effects are significant, and completely disturb the centrosymmetrical nature found in the vertical cavity case (Figure 26). Though the effect of the Rayleigh number and the aspect ratio are qualitatively similar to what has been observed for the vertical cavity, the correlations for the average Nusselt number requires modification in order to include the influence of the curvature C.…”

Section: Vertical Porous Layersmentioning

confidence: 99%

Natural Convection in Porous Media

Bories

1987

Advances in Transport Phenomena in Porous Media

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When the temperature of the saturating fluid phase in a porous medium is not uniform, some flows induced by buoyancy effects may occur. Commonly called free or natural convective movements, these flows depend on density differences due to temperature gradients and boundary conditions. Generally speaking, convective movements which tend to homogenize the whole fluid volume where they take place have two main effects: produce a non-uniform insitu temperature distribu~ tion characterized by hot and cold zones, and increase the overall heat transfer.Due to its numerous applications in geophysics and energyrelated engineering problems, natural convection ili porous media has been receiving increased interest over the last few decades (1,2).In this review, we deal mainly with the presentation of fundamental results obtained through the ~tudy of this phenomena in dispersed saturated porous media. Beginning with the formulation of basic equations and boundary conditions, we then successively review:-first, the results concerning natural convection in homogeneous isotropic porous layers of wide lateral extent in horizontal or inclined positions, -second, the studies on natural convection in confined porous media, i.e., when the lateral extent of the layer is of the same order of magnitude so that the thickness and the lateral thermal boundary effects are taken into account, -and finally, the problems related to natural convection in more complex configurations, such as anisotropic porous layers or porous layers saturated by a fluid of non-constant properties.80

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Section: Vertical Porous Layersmentioning

confidence: 99%

Natural Convection in Porous Media

Bories

1987

Advances in Transport Phenomena in Porous Media

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“…The generalized porous medium model has been applied and several analyses have been conducted by changing both the position and the thickness of the porous layer, both its physical properties and the cavity geometry, by considering a Da number variable into the range 10 -3 -10 -5 and a value of Rayleigh number equal to 3.4 •10 6 . The numerical results underline that the insertion of a porous layer strongly affects the transient evolution of the convective phenomena into the enclosure.…”

Section: Discussionmentioning

confidence: 99%

“…In the scientific literature, steady-state natural convection in vertical porous annuli has been widely investigated; in particular, experimental data-sets have been provided by Reda [3] and Prasad et al [4][5] whereas numerical studies based on the assumption of the Darcy model have been presented in ref. [6][7][8][9][10][11][12]. Among them, notable are the works of Badruddin et al [10][11][12], which analyze the influence of the thermal radiation on the steady free convection in fully porous vertical annuli, taking into account viscous effects [10] and adopting a non-local thermal equilibrium model [12].…”

Section: Introductionmentioning

confidence: 99%

Influence of one porous layer insert on the transient heat transfer in a tall annulus in presence of large source terms

Arpino¹,

Ciccolella²,

Cortellessa³

et al. 2017

IJHT

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This paper provides a sensitivity analysis on the influence of one porous layer insert on the transient behavior of natural convection in a tall annular enclosure in presence of large source terms. The porous medium which partially fills the cavity is characterized by a low value of the Darcy number, typical of insulating materials and metallic foams, often employed in heat exchangers and other engineering applications. A stabilized, fully explicit version of the Compressibility Based Scheme is here employed and validated against experimental data available in the scientific literature for steady and unsteady convection in vertical cylindrical enclosures. Several analyses are presented here by changing both the geometrical features of the cavity and the properties of the porous domain. The results of these analyses demonstrate that not only the thermo-physical properties of the porous medium but also the position and the thickness of the porous layer strongly affect the transient behavior of the convective phenomena occurring in the cavity.

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“…In their studies on vertical annular porous media, Havstad and Burns [1] used perturbation techniques as well as numerical methods to obtain data on heat transfer in vertical cylindrical annuli filled with a porous medium for low Rayleigh numbers. Using finite element technique and an approximate method, Hickox and Gartling [2] analyzed the natural convection flow arising in a vertical annular space insulated at the top and bottom and subjected to uniform but different temperatures of the inside and outside vertical walls.…”

Section: Nomenclaturementioning

confidence: 99%

“…Prasad et al [4] carried out a detailed experimental study of natural convection in a vertical porous annulus. All previous works [1]- [4] deal primarily with mathematical simplification based on the Darcy formulation. Recently, Marpu [5] used the Forchheimer and Brinkman extended Darcy model for studying natural convection heat transfer in a vertical cylindrical porous annulus.…”

Section: Nomenclaturementioning

confidence: 99%

Maximum density effects on natural convection in a vertical annulus filled with a non-Darcy porous medium

Char

Lee

1998

Acta Mechanica

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This article numerically studies the problem of natural convection in a porous medium saturated with cold water, under density inversion, within a vertical annulus. In modeling the flow in the porous medium the non-Darcy effects, which include the Forchheimer inertia and Brinkman viscous effects are taken into account. The governing equations are solved numerically by the finite difference method using the modified strongly implicit procedure. The effects of the inversion parameter Theta(m), radius ratio R*, aspect ratio AR, Forchheimer inertia parameter Fc/Pr, and Darcy number parameter Da on the heat transfer and fluid flow characteristics are discussed in detail. Results show that both the inversion parameter and radius ratio have a significant influence on the flow structure and heat transfer rate in the annulus. It is also found that the mean Nusselt number decreases as the Forchheimer inertia parameter or the Darcy number increases. Moreover, the results obtained here are also compared and favorably agree with numerical results and with experimental data

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Convective heat transfer in vertical cylindrical annuli filled with a porous medium

Cited by 59 publications

References 12 publications

Natural Convection in Porous Media

Natural Convection in Porous Media

Influence of one porous layer insert on the transient heat transfer in a tall annulus in presence of large source terms

Maximum density effects on natural convection in a vertical annulus filled with a non-Darcy porous medium

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