Analysis of natural convection and entropy generation in a cavity filled with multi-layers of porous medium and nanofluid with a heat generation

Al-Zamily, Ali

doi:10.1016/j.ijheatmasstransfer.2016.10.102

Cited by 72 publications

(21 citation statements)

References 15 publications

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“…Maxwell-Garanetts and Brinkman models were used in the present work to find the thermal conductivity and dynamic viscosity of H 2 O-Al 2 O 3 nanofluid; respectively [ 50 , 60 , 61 , 62 , 63 ]. A steady-state single-phase incompressible flow and heat transfer by natural convection inside an annulus filled with nanofluid is considered in the present work.…”

Section: Mathematical Modelingmentioning

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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Section: Mathematical Modelingmentioning

confidence: 99%

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

Aljabair

Mohammed

Alesbe

2020

Heliyon

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“…Maxwell-Garanetts model and Brinkman model are used widely in the previous studies with good accurate results to modeling the thermal conductivity and viscosity in nanofluid respectively [45][46][47][48]. The following assumption are used in this study: steady state incompressible flow, single…”

Section: A Mathematical Modelingmentioning

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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“…Armaghani et al [8] probed features of entropy generation in baffled L-shaped enclosure saturated by water under provision of buoyantly convective thermal differentiated to flow domain along with inclusion of alumina nanoparticles. Zamily et al [9] studied thermo physical features of water along with addition of Ti 2 particles along with checking variation in entropy randomness by locating heat sources at boundaries in cavity. Bouchouch et al [10] examined irreversibility in nanofluid ( 2 / 2 3 ) flow in symmetric enclosure by providing non-isothermal heating through introduction of sinusoidal input.…”

Section: Introductionmentioning

confidence: 99%

Finite Element Simulations for Entropy Generation Measurement in Single Phase Flow of Water Based Nanofluid Filled in Square Cavity under Appliance of Inclined Magnetic field

Bilal¹

2021

Preprint

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Current communication candidly explicates entropy generation process generated due to natural convective heating in square enclosure saturated with nanofluid. Water is used as base fluid and Cu particles are induced to depict enhancement in thermo physical characteristics. Natural convection in enclosure is produced by providing temperature difference on boundaries. Upper wall is provided uniform temperature while rest of walls are kept cold. Impermeability and non-slip conditions are imposed on all walls. Mathematical structuring of considered problem is manifested via continuity, momentum and energy equations under appliance of inclined magnetic field. Thermo physical properties of nanoparticles along with base liquids are used during mathematical structuring. Finite element procedure is adopted to elucidate flow features. Discretization of domain is done by applying hybrid meshing. Velocity and isothermal plots are drawn against concerning parameters. Comprehensive description of energy generation by measuring variation in magnetic, viscous, total and thermal irreversibility’s are also presented. Cut lines representing velocity field in horizontal and vertical direction are also drawn to predict flow behavior at different locations.

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Analysis of natural convection and entropy generation in a cavity filled with multi-layers of porous medium and nanofluid with a heat generation

Cited by 72 publications

References 15 publications

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

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

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

Finite Element Simulations for Entropy Generation Measurement in Single Phase Flow of Water Based Nanofluid Filled in Square Cavity under Appliance of Inclined Magnetic field

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