Entropy generation analysis of thermally developing forced convection in fluid-saturated porous medium

Hooman, Kamel; Ejlali, Arash; Hooman, Faegheh

doi:10.1007/s10483-008-0210-1

Cited by 28 publications

(16 citation statements)

References 21 publications

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“…Three different boundary conditions on the external surface of the channel were considered, and expressions for the Nusselt number, Bejan number and rates of entropy generation were developed. This analysis was later extended to developing flow by considering simple Darcian flow with the LTE condition, under constant temperature boundary conditions [29]. Mahmud and Fraser [30] considered constant, but dissimilar wall temperatures and conducted analytical and numerical studies on the heat transfer and entropy generation characteristics of a fully-filled channel [30].…”

Section: Introductionmentioning

confidence: 99%

Generation of entropy and forced convection of heat in a conduit partially filled with porous media – Local thermal non-equilibrium and exothermicity effects

Torabi

Karimi

Zhang

et al. 2016

Applied Thermal Engineering

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h i g h l i g h t sLocal and total entropy generations in endothermic/exothermic channels are investigated. Convection interface boundary condition has been incorporated into the modelling. Partial filling of the channel with LTE and LTNE for energy equations are considered. Bifurcation phenomena for temperature and local entropy generation are observed. Analytical solutions for temperature and entropy generation rates are obtained. a b s t r a c tThe performance of a two-dimensional, axisymmetric channel with porous inserts attached to the walls is analyzed from the perspective of the first and second laws of thermodynamics. In this analysis, the flow is assumed to be fully developed with a constant heat flux imposed on the external surfaces of the walls, while heat could be internally generated by the fluid and solid phases. Using a Darcy-Brinkman model of momentum transport along with a two-equation thermal energy model, a convective model was developed to describe the thermal boundary conditions on the porous-fluid interface. The so-called Model A was employed on the walls of the channel and semi-analytical solutions were developed for the hydrodynamic, temperature, entropy generation fields and the Nusselt number, and an extensive parametric study was subsequently, conducted. The results indicated that the inclusion of exothermicity leads to significant modifications in the thermal and entropic behaviour of the system. In particular, through comparison with the recent literature, it was demonstrated that exothermicity can significantly impact the influence of the porous-fluid interface model upon the generation of both the local and total entropy within the system.

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Section: Introductionmentioning

confidence: 99%

Generation of entropy and forced convection of heat in a conduit partially filled with porous media – Local thermal non-equilibrium and exothermicity effects

Torabi

Karimi

Zhang

et al. 2016

Applied Thermal Engineering

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“…In practice, the extent of these irreversibilities can be measured by the entropy generation rate. In designing practical systems, it is desirable to minimize the rate of entropy generation and to maximize the available energy Hooman et al (2008), Delavar, and Hedayatpour (2012). The entropy generation induced by natural convection heat transfer in a square cavity was studied by Shahi et al (2011) and found that the Nusselt number increased and the entropy generation reduced as the nanoparticle volume fraction was increased.…”

Section: Introductionmentioning

confidence: 99%

Assisted convective heat transfer and entropy generation in a solar collector filled with nanofluid

Nasrin

Алим²,

Hasanuzzzaman³

2016

J. nav. arch. mar. engg.

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“…In practice, the extent of these irreversibilities can be measured by the entropy generation rate. In designing practical systems, it is desirable to minimize the rate of entropy generation so as to maximize the available energy [7][8][9]. Overall, the results have shown that the rate of entropy generation increases as the irreversibility distribution ratio increase.…”

Section: Introductionmentioning

confidence: 99%

Prandtl number effect on heatline and entropy generation through direct absorption solar collector

Nasrin

Алим

2014

5th Brunei International Conference on Engineering and Technology (BICET 2014)

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Solar energy is often used in applications such as electricity generation, thermal heating and chemical processing due to its renewable and nonpolluting nature. "Flat-plate" type solar heaters are the most cost effective, but these suffer from relatively low efficiency and outlet temperatures. The feasibility of using a direct absorption solar collector (DASC) is analyzed numerically and compared its performance with that of a typical flat-plate collector in the present study. Water and copper nanoparticles-is used as the heat transfer medium. A two-dimensional heat transfer analysis is developed in which direct sunlight is incident on a thin flowing film of nanofluid. The effects of absorption and scattering within the nanofluid are accounted for. The governing partial differential equations are solved using finite element method with Galerkin's weighted residual technique. It is observed that the Prandtl number variation increases the rate of heat loss, collector efficiency and entropy generation for nanofluid more than that of pure water. According to the results obtained from this study, under similar operating conditions, the efficiency of a DASC is found to be higher than that of a flat-plate collector. Generally a DASC performs better than a flat-plate collector, however, much better designed flat-plate collectors might be able to match or outperform a nanofluid based DASC under certain conditions.

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Entropy generation analysis of thermally developing forced convection in fluid-saturated porous medium

Cited by 28 publications

References 21 publications

Generation of entropy and forced convection of heat in a conduit partially filled with porous media – Local thermal non-equilibrium and exothermicity effects

Generation of entropy and forced convection of heat in a conduit partially filled with porous media – Local thermal non-equilibrium and exothermicity effects

Assisted convective heat transfer and entropy generation in a solar collector filled with nanofluid

Prandtl number effect on heatline and entropy generation through direct absorption solar collector

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