Double-diffusive natural convection and entropy generation of Carreau fluid in a heated enclosure with an inner circular cold cylinder (Part I: Heat and mass transfer)

2018 ◽  
Vol 120 ◽  
pp. 731-750 ◽  
Author(s):  
GH.R. Kefayati ◽  
H. Tang
Keyword(s):  
Mass Transfer ◽  
Natural Convection ◽  
Heat And Mass Transfer ◽  
Entropy Generation ◽  
Carreau Fluid ◽  
Double Diffusive

ISPH method for MHD double-diffusive natural convection of a nanofluid within cavity containing open pipes

2019 ◽  
Vol 30 (7) ◽  
pp. 3607-3634 ◽  
Author(s):  
Zehba A.S. Raizah ◽  
Abdelraheem M. Aly
Keyword(s):  
Mass Transfer ◽  
Natural Convection ◽  
Heat And Mass Transfer ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Straight Pipe ◽  
Pipe Length ◽  
Content Type ◽  
Open Pipe ◽  
Double Diffusive

Purpose This paper aims to adopt incompressible smoothed particle hydrodynamics (ISPH) method for studying magnetohydrodynamic (MHD) double-diffusive natural convection from an inner open pipe in a cavity filled with a nanofluid. Design/methodology/approach The Lagrangian description of the governing equations was solved using the current ISPH method. The effects of two pipe shapes as a straight pipe and V-pipe, length of the pipe LPipe (0.2-0.8), length of V-pipe LV (0.04-0.32), Hartmann parameter Ha (40-120), solid volume fraction ϕ (0-0.1) and Lewis number Le (1-50) on the heat and mass transfer of nanofluid have been investigated. Findings The results demonstrate that the average Nusselt and Sherwood numbers are increased by increment on the straight-pipe length, V-pipe length, Hartmann parameter, solid volume fraction and Lewis number. In addition, the variation on the open pipe shapes gives a suitable choice for enhancement heat and mass transfer inside the cavity. The control parameters of the open pipes can enhance the heat and mass transfer inside a cavity. In addition, the variation on the open pipe shapes gives a suitable choice for enhancement heat and mass transfer inside the cavity. Originality/value ISPH method is developed to study the MHD double-diffusive natural convection from the novel shapes of the inner heated open pipes inside a cavity including straight-pipe and V-pipe shapes.

Double Diffusive Magnetohydrodynamic (MHD) Natural Convection and Entropy Generation in a Discretely Heated Inclined Dome-Shaped Enclosure Filled with Cu-Water Nanofluid

2021 ◽  
Vol 10 (4) ◽  
pp. 564-579
Author(s):  
Rujda Parveen ◽  
Priyajit Mondal ◽  
Tapas Ray Mahapatra
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Entropy Generation ◽  
Inclination Angle ◽  
Hartmann Number ◽  
Substantial Impact ◽  
Double Diffusive

This research presents an investigation of laminar two-dimensional double-diffusive free convection and entropy formation in an inclined enclosure under the influence of an inclined magnetic field. The performance of natural convective heat transfer can be improved by doing modifications in enclosure geometry that impact the flow structure. We have considered a dome-shaped enclosure to examine the heat and mass transfer performance. The enclosure is saturated with Cu-water nanofluid and the two sidewalls of the enclosure are maintained at constant temperature Tc(<Th) and concentration cc(<ch). The top-curved wall is adiabatic, and the lower wall is discretely heated and concentrated. The governing equations are first non-dimensionalized and then written in stream function-velocity formulation that is solved numerically using the Bi-CGStab method. A comparison with previously published work in literature is presented and found to be in excellent agreement. Numerical simulations are performed for various values of considered parameters such as Rayleigh number (Ra), Hartmann number (Ha), the orientation of magnetic field (γ), volume fraction of nanoparticles (Φ), and inclination angle of the enclosure (δ). The mentioned parameters have a substantial impact on the cavity flow characteristics. The obtained results demonstrate that the average Sherwood number and Nusselt number are decreasing functions of both the Hartmann number and inclination angle of the enclosure. The minimum heat and mass transfer took place at δ = 135° as the angle of inclination of the enclosure restrains the fluid velocity and reduces the heat transfer rate. Also, entropy generation analysis is conducted for all the considered parameters. The results show that the dome-shaped enclosure has a substantial impact on the fluid flow that enables a smoother and more effective flow inside the cavity, which improves the natural convective heat and mass transmission.

scholarly journals Thermosolutal Natural Convection in Partially Porous Domains

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Dominique Gobin ◽  
Benoît Goyeau
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Natural Convection ◽  
Heat And Mass Transfer ◽  
Fluid Layer ◽  
Horizontal Layer ◽  
Clear Fluid ◽  
Onset Of Convection ◽  
The Stability ◽  
Double Diffusive

In many industrial processes or natural phenomena, coupled heat and mass transfer and fluid flow take place in configurations combining a clear fluid and a porous medium. Since the pioneering work by Beavers and Joseph (1967), the modeling of such systems has been a controversial issue, essentially due to the description of the interface between the fluid and the porous domains. The validity of the so-called one-domain approach—more intuitive and numerically simpler to implement—compared to a two-domain description where the interface is explicitly accounted for, is now clearly assessed. This paper reports recent developments and the current state of the art on this topic, concerning the numerical simulation of such flows as well as the stability studies. The continuity of the conservation equations between a fluid and a porous medium are examined and the conditions for a correct handling of the discontinuity of the macroscopic properties are analyzed. A particular class of problems dealing with thermal and double diffusive natural convection mechanisms in partially porous enclosures is presented, and it is shown that this configuration exhibits specific features in terms of the heat and mass transfer characteristics, depending on the properties of the porous domain. Concerning the stability analysis in a horizontal layer where a fluid layer lies on top of a porous medium, it is shown that the onset of convection is strongly influenced by the presence of the porous medium. The case of double diffusive convection is presented in detail.

scholarly journals Thermosolutal Natural Convection in Partially Porous Domains

2010 ◽  
Author(s):  
Dominique Gobin ◽  
Benoiˆt Goyeau
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Natural Convection ◽  
Heat And Mass Transfer ◽  
Fluid Layer ◽  
Clear Fluid ◽  
Open Problems ◽  
Onset Of Convection ◽  
The Stability ◽  
Double Diffusive

In many industrial processes or natural phenomena coupled heat and mass transfer and fluid flow take place in configurations combining a clear fluid and a porous medium. Since the pioneering work by Beavers and Joseph (1967), the modelling of such systems has been a controversial issue, essentially due to the description of the interface between the fluid and the porous domains. The validity of the so-called one-domain approach — more intuitive and numerically simpler to implement — compared to a two-domain description where the interface is explicitly accounted for, is now clearly assessed. This paper reports recent developments and the current state of the art on this topic, concerning the numerical simulation of such flows as well as the stability studies. The continuity of the conservation equations between a fluid and a porous medium are examined and the conditions for a correct handling of the discontinuity of the macroscopic properties are analyzed. A particular class of problems dealing with thermal and double diffusive natural convection mechanisms in partially porous enclosures is presented, and it is shown that this configuration exhibits specific features in terms of the heat and mass transfer characteristics, depending on the properties of the porous domain. From the viewpoint of the stability of convection in a horizontal layer where a fluid layer lies on top of a porous medium, the analysis shows that the onset of convection is strongly influenced by the presence of the porous medium. The case of thermal convection is fully detailed and many open problems arise in the field of double diffusive convection.

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