Effect of Prandtl Number on Mixed Convective Heat Transfer from a Porous Cylinder in the Steady Flow Regime
The effect of the Prandtl number (<i>Pr</i>) on the flow and heat transfer from a porous circular cylinder with internal heat generation in the mixed convection regime is numerically investigated. The steady flow regime is considered over the ranges of the Reynolds number (<i>Re<...
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MDPI AG
2020-02-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/22/2/184 |
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| author | Shimin Yu Tingting Tang Jianhui Li Peng Yu |
| author_facet | Shimin Yu Tingting Tang Jianhui Li Peng Yu |
| author_sort | Shimin Yu |
| collection | DOAJ |
| description | The effect of the Prandtl number (<i>Pr</i>) on the flow and heat transfer from a porous circular cylinder with internal heat generation in the mixed convection regime is numerically investigated. The steady flow regime is considered over the ranges of the Reynolds number (<i>Re</i>), Darcy number (<i>Da</i>), and Richardson number (<i>Ri</i>), varying from 5 to 40, 10<sup>−6</sup> to 10<sup>−2</sup>, and 0 to 2, respectively. The wake structure, the temperature distribution, and the heat transfer rate are discussed. Besides precipitating the growth of the recirculating wake, the Prandtl number is found to have a significant impact on the thermal characteristics. The concave isotherms, resembling a saddle-shaped structure, occur behind the cylinder at larger <i>Pr</i>, resulting in swells of the isotherms pairing off at the lateral sides. These swells are found to have a negative effect on heat transfer owing to a relatively smaller temperature gradient there. Then, the heat transfer rate in terms of the local Nusselt number (<i>Nu</i>) and enhancement ratio (<i>Er</i>) is calculated, which is closely related to <i>Pr</i>, <i>Re</i>, <i>Da</i>, and <i>Ri.</i> The local minimum heat transfer rate along the cylinder surface is found at the position where the swells of the isotherms form. |
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| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-04-14T03:29:23Z |
| publishDate | 2020-02-01 |
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| spelling | doaj.art-bf1dd1edb5fe477ba9a5c157343f1a952022-12-22T02:15:02ZengMDPI AGEntropy1099-43002020-02-0122218410.3390/e22020184e22020184Effect of Prandtl Number on Mixed Convective Heat Transfer from a Porous Cylinder in the Steady Flow RegimeShimin Yu0Tingting Tang1Jianhui Li2Peng Yu3Harbin Institute of Technology, Harbin 150001, ChinaShenzhen Key Laboratory of Complex Aerospace Flows, Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen 518055, ChinaShenzhen Key Laboratory of Complex Aerospace Flows, Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen 518055, ChinaShenzhen Key Laboratory of Complex Aerospace Flows, Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen 518055, ChinaThe effect of the Prandtl number (<i>Pr</i>) on the flow and heat transfer from a porous circular cylinder with internal heat generation in the mixed convection regime is numerically investigated. The steady flow regime is considered over the ranges of the Reynolds number (<i>Re</i>), Darcy number (<i>Da</i>), and Richardson number (<i>Ri</i>), varying from 5 to 40, 10<sup>−6</sup> to 10<sup>−2</sup>, and 0 to 2, respectively. The wake structure, the temperature distribution, and the heat transfer rate are discussed. Besides precipitating the growth of the recirculating wake, the Prandtl number is found to have a significant impact on the thermal characteristics. The concave isotherms, resembling a saddle-shaped structure, occur behind the cylinder at larger <i>Pr</i>, resulting in swells of the isotherms pairing off at the lateral sides. These swells are found to have a negative effect on heat transfer owing to a relatively smaller temperature gradient there. Then, the heat transfer rate in terms of the local Nusselt number (<i>Nu</i>) and enhancement ratio (<i>Er</i>) is calculated, which is closely related to <i>Pr</i>, <i>Re</i>, <i>Da</i>, and <i>Ri.</i> The local minimum heat transfer rate along the cylinder surface is found at the position where the swells of the isotherms form.https://www.mdpi.com/1099-4300/22/2/184porous cylindermixed convectionthe prandtl numberthe recirculating wakeheat transfer |
| spellingShingle | Shimin Yu Tingting Tang Jianhui Li Peng Yu Effect of Prandtl Number on Mixed Convective Heat Transfer from a Porous Cylinder in the Steady Flow Regime Entropy porous cylinder mixed convection the prandtl number the recirculating wake heat transfer |
| title | Effect of Prandtl Number on Mixed Convective Heat Transfer from a Porous Cylinder in the Steady Flow Regime |
| title_full | Effect of Prandtl Number on Mixed Convective Heat Transfer from a Porous Cylinder in the Steady Flow Regime |
| title_fullStr | Effect of Prandtl Number on Mixed Convective Heat Transfer from a Porous Cylinder in the Steady Flow Regime |
| title_full_unstemmed | Effect of Prandtl Number on Mixed Convective Heat Transfer from a Porous Cylinder in the Steady Flow Regime |
| title_short | Effect of Prandtl Number on Mixed Convective Heat Transfer from a Porous Cylinder in the Steady Flow Regime |
| title_sort | effect of prandtl number on mixed convective heat transfer from a porous cylinder in the steady flow regime |
| topic | porous cylinder mixed convection the prandtl number the recirculating wake heat transfer |
| url | https://www.mdpi.com/1099-4300/22/2/184 |
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