Computational Analysis of Three-Dimensional Unsteady Natural Convection and Entropy Generation in a Cubical Enclosure Filled with Water-Al2O3 Nanofluid

2014 ◽  
Vol 39 (11) ◽  
pp. 7483-7493 ◽  
Author(s):  
Lioua Kolsi ◽  
Ahmed Kadhim Hussein ◽  
Mohamed Naceur Borjini ◽  
H. A. Mohammed ◽  
Habib Ben Aïssia
Keyword(s):  
Natural Convection ◽  
Entropy Generation ◽  
Computational Analysis ◽  
Three Dimensional ◽  
Cubical Enclosure ◽  
Unsteady Natural Convection ◽  
Al2o3 Nanofluid

scholarly journals Three-dimensional unsteady natural convection and entropy generation in an inclined cubical trapezoidal cavity with an isothermal bottom wall

2016 ◽  
Vol 55 (2) ◽  
pp. 741-755 ◽  
Author(s):  
Ahmed Kadhim Hussein ◽  
Kolsi Lioua ◽  
Ramesh Chand ◽  
S. Sivasankaran ◽  
Rasoul Nikbakhti ◽  
...  
Keyword(s):  
Natural Convection ◽  
Entropy Generation ◽  
Three Dimensional ◽  
Bottom Wall ◽  
Unsteady Natural Convection

Effect of Periodic Imposed Heat Flux on Three-Dimensional Natural Convection in a Partially Heated Cubical Enclosure

2016 ◽  
Vol 831 ◽  
pp. 83-91
Author(s):  
Lahoucine Belarche ◽  
Btissam Abourida
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Study ◽  
Control Volume ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Cubical Enclosure ◽  
Simplec Algorithm ◽  
Volume Method

The three-dimensional numerical study of natural convection in a cubical enclosure, discretely heated, was carried out in this study. Two heating square sections, similar to the integrated electronic components, are placed on the vertical wall of the enclosure. The imposed heating fluxes vary sinusoidally with time, in phase and in opposition of phase. The temperature of the opposite vertical wall is maintained at a cold uniform temperature and the other walls are adiabatic. The governing equations are solved using Control volume method by SIMPLEC algorithm. The sections dimension ε = D / H and the Rayleigh number Ra were fixed respectively at 0,35 and 106. The average heat transfer and the maximum temperature on the active portions will be examined for a given set of the governing parameters, namely the amplitude of the variable temperatures a and their period τp. The obtained results show significant changes in terms of heat transfer, by proper choice of the heating mode and the governing parameters.

Fluid flow and heat transfer of a stratified system during natural convection – influence of chamfered corners

2019 ◽  
Vol 29 (2) ◽  
pp. 470-486 ◽  
Author(s):  
Alireza Rahimi ◽  
Aravindhan Surendar ◽  
Aygul Z. Ibatova ◽  
Abbas Kasaeipoor ◽  
Emad Hasani Malekshah
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Natural Convection ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Three Dimensional ◽  
Immiscible Fluids ◽  
Content Type ◽  
Flow And Heat Transfer

Purpose This paper aims to investigate the three-dimensional natural convection and entropy generation in the rectangular cuboid cavities included by chamfered triangular partition made by polypropylene. Design/methodology/approach The enclosure is filled by multi-walled carbon nanotubes (MWCNTs)-H2O nanofluid and air as two immiscible fluids. The finite volume approach is used for computation. The fluid flow and heat transfer are considered with combination of local entropy generation due to fluid friction and heat transfer. Moreover, a numerical method is developed based on three-dimensional solution of Navier–Stokes equations. Findings Effects of side ratio of triangular partitions (SR = 0.5, 1 and 2), Rayleigh number (103 < Ra < 105) and solid volume fraction (f = 0.002, 0.004 and 0.01 Vol.%) of nanofluid are investigated on both natural convection characteristic and volumetric entropy generation. The results show that the partitions can be a suitable method to control fluid flow and energy consumption, and three-dimensional solutions renders more accurate results. Originality/value The originality of this work is to study the three-dimensional natural convection and entropy generation of a stratified system.

Effect of circular cylinder location on three-dimensional natural convection in a cubical enclosure

2015 ◽  
Vol 29 (3) ◽  
pp. 1307-1318 ◽  
Author(s):  
Changyoung Choi ◽  
Hyun Woo Cho ◽  
Man Yeong Ha ◽  
Hyun Sik Yoon
Keyword(s):  
Natural Convection ◽  
Circular Cylinder ◽  
Three Dimensional ◽  
Cubical Enclosure

Numerical Calculation of Three-Dimensional Turbulent Natural Convection in a Cubical Enclosure Using a Two-Equation Model for Turbulence

1986 ◽  
Vol 108 (4) ◽  
pp. 806-813 ◽  
Author(s):  
H. Ozoe ◽  
A. Mouri ◽  
M. Hiramitsu ◽  
S. W. Churchill ◽  
N. Lior
Keyword(s):  
Natural Convection ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Spiral Flow ◽  
Vertical Side ◽  
Turbulent Natural Convection ◽  
Cubical Enclosure ◽  
Side Walls

This paper presents a model and numerical results for turbulent natural convection in a cubical enclosure heated from below, cooled on a portion of one vertical side wall and insulated on all other surfaces. Three-dimensional balances were derived for material, energy, and the three components of momentum, as well as for the turbulent kinetic energy k and the rate of dissipation of turbulent kinetic energy ε. The constants used in the model were the same as those used by Fraikin et al. for two-dimensional convection in a channel. Illustrative transient calculations were carried out for Ra = 106 and 107 and Pr = 0.7. Both the dominant component of the vector potential and the Nusselt number were found to converge to a steady state. Isothermal lines and velocity vectors for vertical cross sections normal to the cooled wall indicated three-dimensional effects near the side walls. A top view of the velocity vectors revealed a downward spiral flow near the side walls along the cooled vertical wall. A weak spiral flow was also found along the side walls near the wall opposing the partially cooled one. The highest values of the eddy diffusivity were 2.6 and 5.8 times the molecular kinematic viscosity for Ra = 106 and 107, respectively. A coaxial double spiral movement, similar to that previously reported for laminar natural convection, was found for the time-averaged flow field. This computing scheme is expected to be applicable to other thermal boundary conditions.

scholarly journals Numerical study of three-dimensional natural convection and entropy generation in a cubical cavity with partially active vertical walls

2017 ◽  
Vol 10 ◽  
pp. 100-110 ◽  
Author(s):  
Abdullah A.A.A Al-Rashed ◽  
Lioua Kolsi ◽  
Ahmed Kadhim Hussein ◽  
Walid Hassen ◽  
Mohamed Aichouni ◽  
...  
Keyword(s):  
Natural Convection ◽  
Entropy Generation ◽  
Numerical Study ◽  
Three Dimensional ◽  
Vertical Walls ◽  
Cubical Cavity

Numerical analysis of entropy generation due to natural convection in three-dimensional partially open enclosures

2017 ◽  
Vol 75 ◽  
pp. 131-140 ◽  
Author(s):  
Hakan F. Oztop ◽  
Lioua Kolsi ◽  
Abdulaziz Alghamdi ◽  
Nidal Abu-Hamdeh ◽  
Mohamed Naceur Borjini ◽  
...  
Keyword(s):  
Natural Convection ◽  
Numerical Analysis ◽  
Entropy Generation ◽  
Three Dimensional
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