The Optimal Spacing between Elliptic Tubes Cooled by Free Convection Using Constructal Theory
The optimal spacing between elliptic tubes cooled by free convection is studied numerically. A row of isothermal elliptic tubes are installed in a fixed volume and the spacing between them is selected according to the constructal theory (Bejan's theory). In this theory the spacing between the t...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Al-Nahrain Journal for Engineering Sciences
2017-06-01
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| Series: | مجلة النهرين للعلوم الهندسية |
| Subjects: | |
| Online Access: | https://nahje.com/index.php/main/article/view/293 |
| _version_ | 1818950376952430592 |
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| author | Ahmed Waheed Mustafa Jaafar Ahmed Zahi |
| author_facet | Ahmed Waheed Mustafa Jaafar Ahmed Zahi |
| author_sort | Ahmed Waheed Mustafa |
| collection | DOAJ |
| description | The optimal spacing between elliptic tubes cooled by free convection is studied numerically. A row of isothermal elliptic tubes are installed in a fixed volume and the spacing between them is selected according to the constructal theory (Bejan's theory). In this theory the spacing between the tubes is chosen such that the heat transfer density is maximized. A finite volume method is employed to solve the governing equations; SIMPLE algorithm with collocated grid is utilized for coupling between velocity and pressure. The range of Rayleigh number is (103 ≤ Ra ≤ 105), the range of the axis ratio of the tubes is (0 ≤ ε ≤ 0.5), and the working fluid is air (Pr =0.71). The results show that the optimal spacing decreases as Rayleigh number increases for all axis ratios, and the maximum density of heat transfer increases as the Raleigh number increases for all axis ratios and the highest value occurs at axis ratio (ε =0) (flat plate) while the lowest value occurs at (ε =0.5) (circular tube). The results also show that the optimal spacing is unchanged with the axis ratio at constant Rayleigh number. |
| first_indexed | 2024-12-20T09:17:37Z |
| format | Article |
| id | doaj.art-1f94d1652fb8494c9a7ba3e43cd03050 |
| institution | Directory Open Access Journal |
| issn | 2521-9154 2521-9162 |
| language | English |
| last_indexed | 2024-12-20T09:17:37Z |
| publishDate | 2017-06-01 |
| publisher | Al-Nahrain Journal for Engineering Sciences |
| record_format | Article |
| series | مجلة النهرين للعلوم الهندسية |
| spelling | doaj.art-1f94d1652fb8494c9a7ba3e43cd030502022-12-21T19:45:23ZengAl-Nahrain Journal for Engineering Sciencesمجلة النهرين للعلوم الهندسية2521-91542521-91622017-06-01203293The Optimal Spacing between Elliptic Tubes Cooled by Free Convection Using Constructal TheoryAhmed Waheed Mustafa0Jaafar Ahmed Zahi1Mechanical Eng. Dep., Coll. of Engineering, AL-Nahrain UniversityMechanical Eng. Dep., Coll. of Engineering, AL-Nahrain UniversityThe optimal spacing between elliptic tubes cooled by free convection is studied numerically. A row of isothermal elliptic tubes are installed in a fixed volume and the spacing between them is selected according to the constructal theory (Bejan's theory). In this theory the spacing between the tubes is chosen such that the heat transfer density is maximized. A finite volume method is employed to solve the governing equations; SIMPLE algorithm with collocated grid is utilized for coupling between velocity and pressure. The range of Rayleigh number is (103 ≤ Ra ≤ 105), the range of the axis ratio of the tubes is (0 ≤ ε ≤ 0.5), and the working fluid is air (Pr =0.71). The results show that the optimal spacing decreases as Rayleigh number increases for all axis ratios, and the maximum density of heat transfer increases as the Raleigh number increases for all axis ratios and the highest value occurs at axis ratio (ε =0) (flat plate) while the lowest value occurs at (ε =0.5) (circular tube). The results also show that the optimal spacing is unchanged with the axis ratio at constant Rayleigh number.https://nahje.com/index.php/main/article/view/293Constructal theoryoptimal spacingelliptic tubesnatural convection |
| spellingShingle | Ahmed Waheed Mustafa Jaafar Ahmed Zahi The Optimal Spacing between Elliptic Tubes Cooled by Free Convection Using Constructal Theory مجلة النهرين للعلوم الهندسية Constructal theory optimal spacing elliptic tubes natural convection |
| title | The Optimal Spacing between Elliptic Tubes Cooled by Free Convection Using Constructal Theory |
| title_full | The Optimal Spacing between Elliptic Tubes Cooled by Free Convection Using Constructal Theory |
| title_fullStr | The Optimal Spacing between Elliptic Tubes Cooled by Free Convection Using Constructal Theory |
| title_full_unstemmed | The Optimal Spacing between Elliptic Tubes Cooled by Free Convection Using Constructal Theory |
| title_short | The Optimal Spacing between Elliptic Tubes Cooled by Free Convection Using Constructal Theory |
| title_sort | optimal spacing between elliptic tubes cooled by free convection using constructal theory |
| topic | Constructal theory optimal spacing elliptic tubes natural convection |
| url | https://nahje.com/index.php/main/article/view/293 |
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