Heat transfer and entropy generation analysis in a three-dimensional impinging jet porous heat sink under local thermal non-equilibrium condition
A precise heat transfer simulation of a three-dimensional impinging jet porous heat sink is presented and is analyzed from thermodynamics vantage point under local thermal non-equilibrium condition. To increase the computational efficiency of the analysis, pore-scale modeling based on lattice Boltzm...
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Veröffentlicht in: | International journal of thermal sciences 2020-07, Vol.153, p.106348, Article 106348 |
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Sprache: | eng |
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Zusammenfassung: | A precise heat transfer simulation of a three-dimensional impinging jet porous heat sink is presented and is analyzed from thermodynamics vantage point under local thermal non-equilibrium condition. To increase the computational efficiency of the analysis, pore-scale modeling based on lattice Boltzmann method (LBM) is used inside the porous media (at a meso-scale), whilst finite volume method (FVM) is employed around it (at a macro-scale). The effects of the Reynolds number, porous layer thickness, solid/fluid thermal conductivity ratio, and porosity on the critical heat transfer and entropy generation parameters are investigated. Additionally, the relations between viscous entropy generation and pressure drop and thermal entropy generation with thermodynamic non-equilibrium are presented. The results indicated that among all parameters, the effects of the porous layer thickness on the fluid permeability are more substantial than other investigated parameters. Also, it is found that increasing the Reynolds number or porous layer thickness increases the total pressure drop, average viscous entropy generation number, and Nusselt number. For each porous layer thickness and Reynolds number, the minimum thermal conductivity ratio (that porous layer had no significant effect on heat transfer) is obtained 200. Moreover, it is determined that increasing the porous layer thickness or reducing the solid/fluid thermal conductivity ratio reduces the thermal entropy generation number, leading to a move toward the local thermal equilibrium condition. Additionally, in contrast to the fluid-phase thermal entropy generation number, the total entropy generation number in most porous layer cases was greater than the entropy generated by the surface without porous media.
•Heat transfer analysis of a 3-D impinging jet heat sink with embedded porous material was carried out.•Entropy generation (EG) analysis of the problem under LTNE condition was performed, using hybrid LBM-FVM.•The relations between VEG and pressure drop and TEG with thermodynamic non-equilibrium are presented.•Total entropy generation number was greater than the entropy generated by the surface without porous media. |
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ISSN: | 1290-0729 1778-4166 |
DOI: | 10.1016/j.ijthermalsci.2020.106348 |