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

scholarly journals Natural Convection and Irreversibility Evaluation in a Cubic Cavity with Partial Opening in Both Top and Bottom Sides

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 116 ◽  
Author(s):  
Hakan Oztop ◽  
Mohammed A. Almeshaal ◽  
Lioua Kolsi ◽  
Mohammed Rashidi ◽  
Mohamed E. Ali
Keyword(s):  
Natural Convection ◽  
Rayleigh Number ◽  
Numerical Study ◽  
Three Dimensional ◽  
Ratio Size ◽  
Partial Opening ◽  
Opening Ratio ◽  
Vertical Walls ◽  
Higher Temperature ◽  
Cubical Cavity

A numerical study on natural convection in a cubical cavity with partial top and bottom openings is performed in this paper. One of the vertical walls of the cavity has higher temperature than that of the opposite one; the remaining walls are insulated perfectly. Three-dimensional simulations of governing equations have been performed using a finite volume technique. The results are presented for different parameters such as opening length and Rayleigh number. It is observed that heat transfer rate and fluid flow can be controlled via opening ratio size and Rayleigh number.

Numerical Study of Three-Dimensional Oscillatory Natural Convection at Low Prandtl Number in Rectangular Enclosures

2000 ◽  
Vol 123 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Shunichi Wakitani
Keyword(s):  
Natural Convection ◽  
Prandtl Number ◽  
Numerical Study ◽  
Three Dimensional ◽  
Width Ratio ◽  
Three Dimensional Flow ◽  
Longitudinal Vortices ◽  
Aspect Ratios ◽  
Vertical Walls ◽  
Prandtl Numbers

Numerical investigations are presented for three-dimensional natural convection at low Prandtl numbers (Pr) from 0 to 0.027 in rectangular enclosures with differentially heated vertical walls. Computations are carried out for the enclosures with aspect ratios (length/height) 2 and 4, and width ratios (width/height) ranging from 0.5 to 4.2. Dependence of the onset of oscillation on the Prandtl number, the aspect ratio, and the width ratio is investigated. Furthermore, oscillatory, three-dimensional flow structure is clarified. The structure is characterized by some longitudinal vortices (rolls) as well as cellular pattern.

scholarly journals The effect of an external magnetic field on the entropy generation in three-dimensional natural convection

2010 ◽  
Vol 14 (2) ◽  
pp. 341-352 ◽  
Author(s):  
Lioua Kolsi ◽  
Awatef Abidi ◽  
Naceur Borjini ◽  
Ben Aïssia
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
External Magnetic Field ◽  
Liquid Metal ◽  
Entropy Generation ◽  
Numerical Study ◽  
Three Dimensional ◽  
Laminar Natural Convection ◽  
The Magnetic Field

A 3-D original numerical study of entropy generation in the case of liquid metal laminar natural convection in a differentially heated cubic cavity and in the presence of an external magnetic field orthogonal to the isothermal walls is carried out. The effect of this field on the various types of irreversibilities is analyzed. It was observed that in the presence of a magnetic field the generated entropy is distributed on the entire cavity and that the magnetic field limits the 3-D character of the distribution of the generated entropy.

Natural convection and entropy generation in a three dimensional volumetrically heated and partially divided cavity

2016 ◽  
Vol 26 (8) ◽  
pp. 2492-2508 ◽  
Author(s):  
Lioua Kolsi ◽  
Nidal Abu-Hamdeh ◽  
Hakan F. Öztop ◽  
Abdulaziz Alghamdi ◽  
Borjini Mohamad Naceur ◽  
...  
Keyword(s):  
Natural Convection ◽  
Entropy Generation ◽  
Control Volume ◽  
Three Dimensional ◽  
Potential Vector ◽  
Content Type ◽  
Volumetric Heating ◽  
Volume Method ◽  
Cubical Cavity ◽  
Rayleigh Numbers

Purpose The purpose of this paper is to provide a solution for natural convection in a cavity with a partial heater in case of volumetric heating and analysis of the entropy generation. Design/methodology/approach The control volume method based on three-dimensional (3D) vorticity-potential vector was applied to solve governing equations of natural convection in a 3D cavity with a fin for different governing parameters as external Rayleigh numbers (103=RaE=106), internal Rayleigh numbers 103=RaI=106, partition height (0.25=h=0.75) and partition location (0.25=c=0.75). A code was written by using Fortran platform. Findings The edge of the fin becomes important on entropy generation. The ratio of the RaI/RaE plays the important role on natural convection and entropy generation. The variation of external Rayleigh number becomes insignificant for the RaI/RaE>1. Originality/value The originality of this work is to analyze the entropy generation and natural convection in a cubical cavity with volumetrically heating.

CFD Analysis of Natural Convection in a Cubic Enclosure Heated From a Side Wall With Experimental Verification Using PIV

2009 ◽  
Author(s):  
Nuri Alpay Ku¨rekci
Keyword(s):  
Natural Convection ◽  
Numerical Study ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Side Wall ◽  
Velocity Measurements ◽  
Dimensional Solution ◽  
Image Velocimetry ◽  
Vertical Walls ◽  
Good Agreement

Natural convection of air in a cubical volume is investigated experimentally and numerically. A cubical volume of 20×20×20 cm dimensions was built for the experimental study. One of the vertical walls covering the volume is hot, the other one is cold and the rest are adiabatic. Three walls are made of aluminum and the others are made of heat-resistant glass. The hot wall temperature is kept constant during the experiments by means of an electrical heater. The cold wall is at the ambient temperature. Other adiabatic surfaces are insulated with polyurethane foam. Experiments are performed in an air-conditioned room at 21°C. PIV (Particle Image Velocimetry) is used for velocity measurements. The FLUENT CFD software package is used for the numerical study. A three-dimensional solution is obtained for the laminar flow case for a 61×61×61 grid. The numerical and experimental results are compared with each other for the validation of the numerical solution under the testing conditions of TH = 69°C, TC = 41°C and Ra = 1.3×107. Results obtained from the numerical and experimental studies are in a reasonably good agreement with each other.

EXPERIMENTAL AND NUMERICAL STUDY OF THREE-DIMENSIONAL NATURAL CONVECTION AND FREEZING IN WATER

1994 ◽  
Author(s):  
C. Abegg ◽  
Graham de Vahl Davis ◽  
W.J. Hiller ◽  
St. Koch ◽  
Tomasz A. Kowalewski ◽  
...  
Keyword(s):  
Natural Convection ◽  
Numerical Study ◽  
Three Dimensional

Effects of moving lid direction on mixed convection and entropy generation in a cubical cavity with longitudinal triangular fin insertion

2017 ◽  
Vol 27 (4) ◽  
pp. 839-860 ◽  
Author(s):  
Lioua Kolsi ◽  
Hakan F. Öztop ◽  
Nidal Abu-Hamdeh ◽  
Borjini Mohamad Naceur ◽  
Habib Ben Assia
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Three Dimensional ◽  
Thermal Conductivity Ratio ◽  
Governing Equations ◽  
Content Type ◽  
Driven Cavity ◽  
Triangular Fin ◽  
Cubical Cavity ◽  
3D Problem

Purpose The main purpose of this work is to arrive at a three-dimensional (3D) numerical solution on mixed convection in a cubic cavity with a longitudinally located triangular fin in different sides. Design/methodology/approach The 3D governing equations are solved via finite volume technique by writing a code in FORTRAN platform. The governing parameters are chosen as Richardson number, 0.01 ≤ Ri ≤ 10 and thermal conductivity ratio 0.01 ≤ Rc ≤ 100 for fixed parameters of Pr = 0.7 and Re = 100. Two cases are considered for a lid-driven wall from left to right (V+) and right to left (V−). Findings It is observed that entropy generation due to heat transfer becomes dominant onto entropy generation because of fluid friction. The most important parameter is the direction of the moving lid, and lower values are obtained when the lid moves from right to left. Originality The main originality of this work is to arrive at a solution of a 3D problem of mixed convection and entropy generation for lid-driven cavity with conductive triangular fin attachments.

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