Natural Convection Heat Transfer Enhancement in a Square Cavity Periodically Cooled from Above

Raji, A.; Hasnaoui, M.; Firdaouss, Mouaouia; Ouardi, C

doi:10.1080/10407782.2013.733248

Cited by 43 publications

(22 citation statements)

References 28 publications

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“…cylinder, derived for the subcritical case, was found to be valid up to slightly supercritical Ra value. Raji et al [14] presented a numerical results of the natural convection in a square cavity filled with air, the temperature of the lower horizontal surface is kept constant(hot), while that of the upper surface is maintained at a cold temperature, the remaining upright walls are considered adiabatic. The Rayleigh number was considered in the range 10 3 < Ra < 7×10 6 .…”

Section: Introductionmentioning

confidence: 99%

Onset of Natural Convection and Transition Laminar-Oscillatory Convection Flow in Rayleigh-Bénard Configuration

Bouabdallah¹,

Ghernaout²,

Teggar³

et al. 2016

IJHT

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A numerical study of Rayleigh-Bé nard convection in a rectangular cavity has been presented. The onset of natural convection and the transition from laminar to oscillatory convection were considered in this study. The finite volume method was used to solve numerically the governing equations of the phenomenon and the pressure-velocity coupling was matched by SIMPLER Algorithm of Patankar. This study was carried out for Rayleigh number varied from 10 3 to 10 6 in order to control the first value of critical Rayleigh number, Rac-1 corresponding the onset of convection, and that for different aspect ratios of the cavity. The threshold transition regime of laminar-oscillatory convection is depicted by the second critical Rayleigh number Rac-2. Also, the different modes of bifurcation of convection were determined and discussed.

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Section: Introductionmentioning

confidence: 99%

Onset of Natural Convection and Transition Laminar-Oscillatory Convection Flow in Rayleigh-Bénard Configuration

Bouabdallah¹,

Ghernaout²,

Teggar³

et al. 2016

IJHT

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“…For transient analysis, the study of Raji et al [29] are validated for Ra = 10 5 and amplitude 0.4 ( figure 2(b)) and 0.67 ( figure 2(c)). The results are in excellent agreement with the earlier reports of research.…”

Section: Code Validationmentioning

confidence: 99%

Natural convection heat transfer enhancement using nanofluid and time-variant temperature on the square enclosure with diagonally constructed twin adiabatic blocks

Kalidasan¹,

Velkennedy²,

Kanna

2016

Applied Thermal Engineering

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“…More specifically, the heatlines display the microscopic heat transfer process, which is different from the conventional Nusselt number that macroscopically describes the heat transfer rate; they show non-crossed corridors for heat flow and their shapes give a global picture of heat transport. The dimensionless heat function is obtained using a similar procedure as that given in (Raji et al, 2013;Kimura and Bejan, 1983). The local Nusselt numbers along the horizontal and vertical walls are respectively given by:…”

Section: Heat Transfermentioning

confidence: 99%

“…In fact, the origin of this complexity is attributed to the occurrence of many levels of instabilities (onset of convection, transitions towards single and multiple periodic regimes, transition towards chaotic regimes ...) and eventual existence of multiplicity of solutions, characterized by their 1 on the shape of the confining configuration and the imposed boundary conditions, whose combination control the generated flow structure and temperature distribution within the systems under study. Although the phenomenon of Rayleigh-Bénard convection in rectangular configurations was the subject of many previous works (Pallares et al, 1999;Calgagni et al, 2005;Kao and Yang, 2007;Platten et al, 2007, Raji et al, 2013, the topic remains an attractive field of investigation. In fact, further understanding of the system behaviors are required, mainly, when thermal excitations on the sidewalls are changed from adiabatic or periodic conditions to linear imposed temperatures.…”

Section: Introductionmentioning

confidence: 99%

MRT-LBM Simulation of Natural Convection in a Rayleigh-Benard Cavity With Linearly Varying Temperatures on the Sides: Application to a Micropolar Fluid

Mansouri¹,

Hasnaoui²,

Amahmid³

et al. 2017

Frontiers in Heat and Mass Transfer

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A two-dimensional numerical simulation is conducted to study natural convection flow and heat transfer characteristics in a square cavity filled with a micropolar fluid. The lower and upper walls of the cavity are respectively subject to isothermal heating and cooling while the temperatures of both vertical sides decrease linearly in the upwards direction. The Lattice-Boltzmann Method (LBM), with the multi-relaxation time (MRT) scheme for the collision process, is used to solve the problem with the objective to assess the ability and efficiency of this numerical method to describe the micropolar fluid behavior under the effect of the imposed thermal boundary conditions. Computations are carried out for Rayleigh number, , and material parameter (vortex viscosity), , varying respectively in the ranges 10 3  10 6 and 0 2. Combined effects of these parameters on the multiplicity of solutions and critical values of from which transitions occur are investigated for Pr 7. An increase of the material parameter is shown to increase the critical Rayleigh numbers, which confirms the stabilizing effect of the micropolar fluid compared to the Newtonian case ( 0). The study covers both steady and unsteady aspects of the problem under consideration. Initial perturbations play an important role in the cooling process of the hot bottom wall in the present configuration. The bicellular ascending and descending flows are two solutions mirror images of each other but they lead to very different quantities of heat from the bottom wall.

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Natural Convection Heat Transfer Enhancement in a Square Cavity Periodically Cooled from Above

Cited by 43 publications

References 28 publications

Onset of Natural Convection and Transition Laminar-Oscillatory Convection Flow in Rayleigh-Bénard Configuration

Onset of Natural Convection and Transition Laminar-Oscillatory Convection Flow in Rayleigh-Bénard Configuration

Natural convection heat transfer enhancement using nanofluid and time-variant temperature on the square enclosure with diagonally constructed twin adiabatic blocks

MRT-LBM Simulation of Natural Convection in a Rayleigh-Benard Cavity With Linearly Varying Temperatures on the Sides: Application to a Micropolar Fluid

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