Comment on “Combined Forced and Free Convective Flow in a Vertical Porous Channel: The Effects of Viscous Dissipation and Pressure Work” by A. Barletta and D. A. Nield, Transport in Porous Media, DOI 10.1007/s11242-008-9320-y, 2009

2009 ◽  
Vol 80 (2) ◽  
pp. 389-395 ◽  
Author(s):  
E. Magyari
Keyword(s):  
Porous Media ◽  
Viscous Dissipation ◽  
Convective Flow ◽  
Porous Channel ◽  
Free Convective Flow ◽  
Pressure Work ◽  
Transport In Porous Media

scholarly journals Unstable Density-Driven Flow in Fractured Porous Media: The Fractured Elder Problem

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 168
Author(s):  
Paiman Shafabakhsh ◽  
Marwan Fahs ◽  
Behzad Ataie-Ashtiani ◽  
Craig T. Simmons
Keyword(s):  
Porous Media ◽  
Convective Flow ◽  
Critical Rayleigh Number ◽  
Fracture Density ◽  
Fracture Networks ◽  
Homogeneous Case ◽  
Free Convective Flow ◽  
Density Driven Flow ◽  
Specific Fracture ◽  
Homogenous Case

The Elder problem is one of the well-known examples of an unstable density-driven flow (DDF) and solute transport in porous media. The goal of this research is to investigate the influence of fracture networks on this benchmark problem due to the great importance of the fractured heterogeneity effect on unstable DDF. For this aim, the fractured Elder problem is solved using COMSOL Multiphysics, which is a finite element method simulator. Uniform and orthogonal fracture networks are embedded to analyze free convective flow and development of unstable salt plumes. The results indicate that the mesh sensitivity of the fractured Elder problem is greater than the homogeneous case. Furthermore, it has been shown that in the fractured cases, the onset of instability and free convection occur with lower critical Rayleigh number, which means that fracture networks have a destabilizing effect. Also, we examined the structural properties of fracture networks that control convective flow patterns, and the simulation results show that the strength of convection and instability at the beginning of the intrusion is proportional to the aperture size of the fractures. Moreover, the increase of the fracture’s density leads different modes of transient convective modes, until a specific fracture density after which the transient convective modes become similar to the homogenous case.

scholarly journals The Effect of Internal and External Heating on the Free Convective Flow of a Bingham Fluid in a Vertical Porous Channel

Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 95 ◽  
Author(s):  
D. Andrew S. Rees ◽  
Andrew P. Bassom
Keyword(s):  
Convective Flow ◽  
Internal Heat ◽  
Bingham Fluid ◽  
Relative Strength ◽  
Porous Channel ◽  
Free Convective Flow ◽  
Bingham Number ◽  
Different Types ◽  
Yield Surfaces ◽  
Rayleigh Numbers

We study the steady free convective flow of a Bingham fluid in a porous channel where heat is supplied by both differential heating of the sidewalls and by means of a uniform internal heat generation. The detailed temperature profile is governing by an external and an internal Darcy-Rayleigh number. The presence of the Bingham fluid is characterised by means of a body force threshold as given by the Rees-Bingham number. The resulting flow field may then exhibit between two and four yield surfaces depending on the balance of magnitudes of the three nondimensional parameters. Some indication is given of how the locations of the yield surfaces evolve with the relative strength of the Darcy-Rayleigh numbers and the Rees-Bingham number. Finally, parameter space is delimited into those regions within which the different types of flow and stagnation patterns arise.

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