Entropy generation and natural convection in rectangular cavities

Oliveski, Rejane De Césaro; Macagnan, Mário Henrique; Copetti, Jacqueline Biancon

doi:10.1016/j.applthermaleng.2008.07.012

Cited by 144 publications

(46 citation statements)

References 22 publications

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“…The main idea behind thermodynamic optimization is to relate degree of thermodynamic non-ideality of the design to the physical characteristics of the system, such as finite dimensions, shapes, materials, finite speeds, and finite-time of intervals of operation and vary one or more physical characteristics to optimize the design characterized by minimum entropy generation subject to finite-size and finite-constraints [22,23]. The EGM approach has been applied to optimize natural convection systems [24,25], pin-fin heat sinks [26], fuel cells [27], heat exchangers [28,29], environmental control of aircraft [30,31], combustion in porous media [32], etc.…”

Section: Introductionmentioning

confidence: 99%

Entropy Generation During Natural Convection in a Porous Cavity: Effect of Thermal Boundary Conditions

Basak

Kaluri

Balakrishnan

2012

Numerical Heat Transfer, Part A: Applications

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Entropy generation plays a significant role in the overall efficiency of a given system, and a judicious choice of optimal boundary conditions can be made based on a knowledge of entropy generation. Five different boundary conditions are considered and their effect of the permeability of the porous medium, heat transfer regime (conduction and convection) on entropy generation due to heat transfer, and fluid friction irreversibilities are investigated in detail for molten metals (Pr ¼ 0.026) and aqueous solutions (Pr ¼ 10), with Darcy numbers (Da) between 10 À5 -10 À3 and at a representative high Rayleigh number, Ra ¼ 5 Â 10 5 . It is observed that the entropy generation rates are reduced in sinusoidal heating (case 2) when compared to that for uniform heating (case 1), with a penalty on thermal mixing. Finally, the analysis of total entropy generation due to variation in Da and thermal mixing and temperature uniformity indicates that, there exists an intermediate Da for optimal values of entropy generation, thermal mixing, and temperature uniformity.

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Section: Introductionmentioning

confidence: 99%

Entropy Generation During Natural Convection in a Porous Cavity: Effect of Thermal Boundary Conditions

Basak

Kaluri

Balakrishnan

2012

Numerical Heat Transfer, Part A: Applications

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“…The bottom and the roof sides are insulated. In this case, when H 0 = 0, then the enclosure structure limits to the rectangular shape that has been studied by Oliveski et al [18] and Famouri and Hooman [19]. 2.…”

Section: Description Of Models Geometriesmentioning

confidence: 92%

Heat transfer in a large triangular-roof enclosure based on the second law analysis

Ziapour

Dehnavi

2014

Heat Mass Transfer

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“…As the generation of entropy affects the system efficiency, its minimization can be used as the optimal design criteria for thermal systems [33,34]. Oliveski et al have investigated about the natural convection process caused by temperature differences between the vertical walls of cavities [34]. They confirmed that in the natural convection process the entropy generation is mainly associated to the heat transfer and to the fluid flow friction.…”

Section: Exergy Transfer By Convectionmentioning

confidence: 95%

“…These irreversibilities result on energy losses, and this effect induces entropy generation inside of the system. As the generation of entropy affects the system efficiency, its minimization can be used as the optimal design criteria for thermal systems [33,34]. Oliveski et al have investigated about the natural convection process caused by temperature differences between the vertical walls of cavities [34].…”

Section: Exergy Transfer By Convectionmentioning

confidence: 99%