Thermal nonequilibrium porous convection in a heat generating medium

Saravanan, S.; Brinda, R.

doi:10.1016/j.ijmecsci.2017.10.024

Cited by 11 publications

(5 citation statements)

References 36 publications

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“…The evolution of the fluid flow within porous media has received a great attention because of its importance in geophysical and energy-related engineering problems as well as in the environment such as heat transfer and flow in solar ponds [1], electronic equipment cooling [2], post-accident cooling of nuclear reactors, packed bed solar energy storage, geothermal extraction, energy storage devices, thermal insulation systems and contaminant transport in groundwater [3], thermal design of buildings, commercial refrigeration [4]. Other areas of applications are in food processing, grain storage, soil heating, storage of radioactive waste, porous radiant burners [5], and uncovered flat plate solar collectors having rows of vertical strips collector [6] etc. The classical free convection in horizontal porous layers uniformly heated from below was studied about 40 years ago, beginning with the pioneering studies of Horton and Rogers [7] with other of Lapwood [8].…”

Section: Introductionmentioning

confidence: 99%

“…They have concluded that flow field inside the box is really complex due to both opening side and moving wall of the cavity and the heat transfer rate becomes stronger for higher values of Grashof number and boosting of heater length. A companion paper of Saravanan et al [5] was based on the effects of the thermal non-equilibrium effects on natural convection inside a square cavity by internal heat generation with different boundary conditions for symmetrical cooling. A bifurcation was observed when the system moves towards thermal equilibrium.…”

Section: Introductionmentioning

confidence: 99%

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Symmetry-Breaking in a Porous Cavity with Moving Side Walls

Menacer

Boudebous

Slimani³

et al. 2022

JERA

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In this paper, a numerical investigation of the steady laminar mixed convection flow in a porous square enclosure has been considered. This structure represents a practical system such as an external through flow of cooled-air an electronic device from its moving sides. The heating was supplied by an internal volumetric source with an uniform distribution at the middle part of its bottom, while the other walls were assumed thermally insulated. Moreover, the momentum transfer in the porous substrate was numerically investigated using the Darcy-Brinkman-Forchheimer law. The governing equations of the posed problem have been solved by applying the finite difference technique on non-uniform grids. For all simulations, the Reynolds number and the porosity have been fixed respectively to Re=100 and φ=0.9. Darcy’s value was varied in the range from 0.001 to 0.1. The results detected the existence of a radical change in the contour patterns for Richardson number equal to 11.76 and 11.77 with fixed Da=0.1. This behavior signified that the fluid is fully convected for higher Darcy number.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Symmetry-Breaking in a Porous Cavity with Moving Side Walls

Menacer

Boudebous

Slimani³

et al. 2022

JERA

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show abstract

“…Natural convective heat transfer characteristics in enclosures have a great significance in industrial applications such as solar collectors, thermal storage systems, cooling of nuclear reactors, etc. In past years, different methods were used to augment the heat transfer in enclosures such as using porous media [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] and nanotechnology [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. The corrugated annulus is a type of enhanced heat transfer techniques.…”

Section: Introductionmentioning

confidence: 99%

Natural convection heat transfer in corrugated annuli with H2O-Al2O3 nanofluid

Aljabair

Mohammed

Alesbe

2020

Heliyon

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The present work includes a numerical study of natural convection heat transfer in symmetrical and unsymmetrical corrugated annuli filled with H 2 O-Al 2 O 3 nanofluid. In this study, higher and lower temperatures were kept constant at inner and outer cylinders of the annulus; respectively. Eight mathematical models with an aspect ratio of 1.5 were developed to find the best model giving the highest heat transfer rates. The stream-vorticity formulation in curvilinear coordinates was used to solve the governing equations of heat transfer and fluid motion. The influences of Rayleigh number. ðð10 3 Ra 10 6 Þ and volume fraction of nanoparticles. (0 ϕ 0:25Þ on isotherms, streamlines, local and average Nusselt numbers on the inner and outer cylinder were investigated. The results show that the heat transfer rate is significantly increased with an increase in nanoparticles volume fraction and Rayleigh number. The activity of the heated surface is increased with an increase in the undulation number, but the flow motion tends to be most difficult in the spaces between active undulation walls. Moreover, the heat transfer rates in unsymmetrical annuli are relatively higher than the rates in the symmetrical annuli. There are no evident changes in isotherms with an increase in the nanofluid volume fraction. Correlations for the mean Nusselt number on the inner and outer walls of annulus were deduced as a function of Rayleigh number and nanoparticles volume fraction for eight models with an accuracy range of 8-15 %.

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“…Applications include effective cooling system for electronic components, solar collectors, thermal storage system, nuclear reactors, etc. In recent years, there are many attempts from researchers using different methods to enhance the heat transfer rate using of porous media [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and nanotechnology . The present study has used the second method.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Natural Convection Heat Transfer Phenomena of Nanofluids in Corrugated Annulus

Aljobair¹,

Mohammed²,

Alesbe³

2020

Preprint

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Abstract The natural convection heat transfer and fluid flow characteristic of water based Al2O3 nano-fluids in a symmetrical and unsymmetrical corrugated annulus enclosure has been studied numerically using CFD. The inner cylinder is heated isothermally while the outer cylinder is kept constant cold temperature. The study includes eight models of corrugated annulus enclosure with constant aspect ratio of 1.5. The governing equations of fluid motion and heat transfer are solved using stream-vorticity formulation in curvilinear coordinates. The range of solid volume fractions of nanoparticles extends from PHI=0 to 0.25, and Rayleigh number varies from 104 to 107. Streamlines, isotherms, local and average Nusselt number of inner and outer cylinder has been investigated in this study. Sixty-four correlations have been deduced for the average Nusselt number for the inner and outer cylinders as a function of Rayleigh number have been deduced for eight models and five values of volume fraction of nano particles with an accuracy range 6-12 %. The results show that, the average heat transfer rate increases significantly as particle volume fraction and Rayleigh number increase. Also, increase the number of undulations in unsymmetrical annuli reduces the heat transfer rates which remain higher than that in symmetrical annuli. There is no remarkable change in isotherms contour with increase of volume fraction of nanofluid.

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Thermal nonequilibrium porous convection in a heat generating medium

Cited by 11 publications

References 36 publications

Symmetry-Breaking in a Porous Cavity with Moving Side Walls

Symmetry-Breaking in a Porous Cavity with Moving Side Walls

Natural convection heat transfer in corrugated annuli with H2O-Al2O3 nanofluid

Prediction of Natural Convection Heat Transfer Phenomena of Nanofluids in Corrugated Annulus

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