Porous and Complex Flow Structures in Modern Technologies

Bejan, Adrian; Dinçer, İbrahim; Lorente, Sylvie; Miguel, António F.; Reis, A. Heitor

doi:10.1007/978-1-4757-4221-3

Cited by 341 publications

(289 citation statements)

References 0 publications

Supporting

Mentioning

285

Contrasting

Order By: Relevance

“…As a result, heat and fluid flow in such cavities have been studied extensively for the past several decades. For a recent survey of literature one may consult Nield and Bejan [1], Ingham and Pop [2], Vafai [3], and Bejan et al [4].…”

Section: Introductionmentioning

confidence: 99%

Heatline and Energy-Flux-Vector Visualization of Natural Convection in a Porous Cavity Occupied by a Fluid with Temperature-Dependent Viscosity

2009

View full text Add to dashboard Cite

Temperature-dependent viscosity effects in buoyancy driven flow in a porous-saturated enclosure is studied numerically, based on the general model of momentum transfer in a porous medium based on the Arrhenius model, which proposes an exponential form of viscosity-temperature relation. Effects of fluid viscosity variation on isotherms, streamlines, and the Nusselt number are studied. Both cases of viscosity increase and decrease versus temperature is considered. Application of the effective Rayleigh number concept and the reference temperature approach are investigated. Moreover, heatlines and the energy flux vectors are illustrated for a more comprehensive analysis of the problem.

show abstract

Section: Introductionmentioning

confidence: 99%

Heatline and Energy-Flux-Vector Visualization of Natural Convection in a Porous Cavity Occupied by a Fluid with Temperature-Dependent Viscosity

2009

View full text Add to dashboard Cite

show abstract

“…The ducts are round capillary tubes of different radii (R i ) and lengths (L i ; i=0,1,…,n). The radii and lengths of the ducts are sized relative to one another, in accordance with [17,25,26]:…”

Section: Geometric and Operational Parametersmentioning

confidence: 99%

“…The relationship between the size of the first duct (level 0) and the size of the ducts at level i is given by One basic feature of tree-shaped networks is that pairing, or bifurcation of ducts (dichotomy), is an optimized feature of the flow architecture (see for example [17,25]). Therefore, m takes a value of 2.…”

Section: Geometric and Operational Parametersmentioning

confidence: 99%

“…Research on tree-shaped capillary networks, though dating back one century [17], is still a topic of great interest due to its widespread applications in physics, biology, geology and engineering. The simulation of fluid flow through these structures requires an accurately knowledge of the *Address correspondence to this author at the Department of Physics and Geophysics Centre of Évora, University of Évora, Portugal; E-mail: afm@uevora.pt pressure distribution of a fluid through the structure.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An Analytic Approach to Capillary Pressure in Tree-Shaped Networks

Miguel

2008

TOTHERJ

View full text Add to dashboard Cite

This study analyzes the pressure in capillary tree-shaped networks, based on the thermodynamics and the geometric description of the network. The presence of equilibrium and non-equilibrium effects on pressure is accounted. In particular, the presence of equilibrium effects is shown to be essential for describing the pressure in the network. An approach to the definition of equilibrium capillary pressure is presented in terms of interfacial energies of the phases but also in terms of the geometry characteristics of the tree-shaped network. Among other, the equilibrium capillary pressure is shown to depend on number of branching levels and number of daughter branches. Finally, a criterion is established to evaluate the importance of equilibrium and non-equilibrium effects on the capillary pressure.

show abstract

“…It is also a subject of interest in environmental and geophysics sciences. A wide applications of the porous media can be found in the well known books by Nield and Bejan (2006), Ingham and Pop (2005), Liu and Masliyah (2005), Vafai (2010), Pop and Ingham (2001), Bejan et al (2004), and Vadasz (2008), and in the recent article by Harris et al (2009). They provide significant information on porous media application as well as basic description of heat and fluid flow in porous media.…”

Section: Introductionmentioning

confidence: 99%

Fully Developed Forced Convection Heat Transfer in a Porous Channel with Asymmetric Heat Flux Boundary Conditions

et al. 2011

View full text Add to dashboard Cite

An analytical study is performed on steady, laminar, and fully developed forced convection heat transfer in a parallel plate channel with asymmetric uniform heat flux boundary conditions. The channel is filled with a saturated porous medium, and the lower and upper walls are subjected to different uniform heat fluxes. The dimensionless form of the DarcyBrinkman momentum equation is solved to determine the dimensionless velocity profile, while the dimensionless energy equation is solved to obtain temperature profile for a hydrodynamically and thermally fully developed flow in the channel. Nusselt numbers for the lower and upper walls and an overall Nusselt number are defined. Analytical expressions for determination of the Nusselt numbers and critical heat flux ratio, at which singularities are observed for individual Nusselt numbers, are obtained. Based on the values of critical heat flux ratio and Darcy number, a diagram is provided to determine the direction of heat transfer between the lower or upper walls while the fluid is flowing in the channel.

show abstract

Porous and Complex Flow Structures in Modern Technologies

Abstract: Porous and complex flow structures in modern technologies / Adrian Bejan. .. [et al.]. p. cm. Includes bibliographical references and index.

Cited by 341 publications

References 0 publications

Heatline and Energy-Flux-Vector Visualization of Natural Convection in a Porous Cavity Occupied by a Fluid with Temperature-Dependent Viscosity

Heatline and Energy-Flux-Vector Visualization of Natural Convection in a Porous Cavity Occupied by a Fluid with Temperature-Dependent Viscosity

An Analytic Approach to Capillary Pressure in Tree-Shaped Networks

Fully Developed Forced Convection Heat Transfer in a Porous Channel with Asymmetric Heat Flux Boundary Conditions

Contact Info

Product

Resources

About