Oberbeck–Boussinesq free convection of water based nanoliquids in a vertical channel using Dirichlet, Neumann and Robin boundary conditions on temperature
A numerical investigation is carried out into the flow and heat transfer within a fully-developed mixed convection flow of water–alumina (Al2O3–water), water–titania (TiO2–water) and water–copperoxide (CuO–water) in a vertical channel by considering Dirichlet, Neumann and Robin boundary conditions....
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2016-09-01
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| Series: | Alexandria Engineering Journal |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1110016816301247 |
| _version_ | 1818905622856335360 |
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| author | Nur Asiah Mohd Makhatar P.G. Siddheshwar Habibis Saleh Ishak Hashim |
| author_facet | Nur Asiah Mohd Makhatar P.G. Siddheshwar Habibis Saleh Ishak Hashim |
| author_sort | Nur Asiah Mohd Makhatar |
| collection | DOAJ |
| description | A numerical investigation is carried out into the flow and heat transfer within a fully-developed mixed convection flow of water–alumina (Al2O3–water), water–titania (TiO2–water) and water–copperoxide (CuO–water) in a vertical channel by considering Dirichlet, Neumann and Robin boundary conditions. Actual values of thermophysical quantities are used in arriving at conclusions on the three nanoliquids. The Biot number influences on velocity and temperature distributions are opposite in regions close to the left wall and the right wall. Robin condition is seen to favour symmetry in the flow velocity whereas Dirichlet and Neumann conditions skew the flow distribution and push the point of maximum velocity to the right of the channel. A reversal of role is seen between them in their influence on the flow in the left-half and the right-half of the channel. This leads to related consequences in heat transport. Viscous dissipation is shown to aid flow and heat transport. The present findings reiterate the observation on heat transfer in other configurations that only low concentrations of nanoparticles facilitate enhanced heat transport for all three temperature conditions. Significant change was observed in Neumann condition, whereas the changes are too extreme in Dirichlet condition. It is found that Robin condition is the most stable condition. Further, it is also found that all three nanoliquids have enhanced heat transport compared to that by base liquid, with CuO–water nanoliquid shows higher enhancement in its Nusselt number, compared to Al2O3 and TiO2. |
| first_indexed | 2024-12-19T21:26:16Z |
| format | Article |
| id | doaj.art-09efa0ccd56b45e7872dd2fa782e3e47 |
| institution | Directory Open Access Journal |
| issn | 1110-0168 |
| language | English |
| last_indexed | 2024-12-19T21:26:16Z |
| publishDate | 2016-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Alexandria Engineering Journal |
| spelling | doaj.art-09efa0ccd56b45e7872dd2fa782e3e472022-12-21T20:05:07ZengElsevierAlexandria Engineering Journal1110-01682016-09-015532285229710.1016/j.aej.2016.05.010Oberbeck–Boussinesq free convection of water based nanoliquids in a vertical channel using Dirichlet, Neumann and Robin boundary conditions on temperatureNur Asiah Mohd Makhatar0P.G. Siddheshwar1Habibis Saleh2Ishak Hashim3School of Mathematical Sciences, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, MalaysiaDepartment of Mathematics, Bangalore University, Central College Campus, Bangalore 560 001, IndiaSchool of Mathematical Sciences, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, MalaysiaSchool of Mathematical Sciences, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, MalaysiaA numerical investigation is carried out into the flow and heat transfer within a fully-developed mixed convection flow of water–alumina (Al2O3–water), water–titania (TiO2–water) and water–copperoxide (CuO–water) in a vertical channel by considering Dirichlet, Neumann and Robin boundary conditions. Actual values of thermophysical quantities are used in arriving at conclusions on the three nanoliquids. The Biot number influences on velocity and temperature distributions are opposite in regions close to the left wall and the right wall. Robin condition is seen to favour symmetry in the flow velocity whereas Dirichlet and Neumann conditions skew the flow distribution and push the point of maximum velocity to the right of the channel. A reversal of role is seen between them in their influence on the flow in the left-half and the right-half of the channel. This leads to related consequences in heat transport. Viscous dissipation is shown to aid flow and heat transport. The present findings reiterate the observation on heat transfer in other configurations that only low concentrations of nanoparticles facilitate enhanced heat transport for all three temperature conditions. Significant change was observed in Neumann condition, whereas the changes are too extreme in Dirichlet condition. It is found that Robin condition is the most stable condition. Further, it is also found that all three nanoliquids have enhanced heat transport compared to that by base liquid, with CuO–water nanoliquid shows higher enhancement in its Nusselt number, compared to Al2O3 and TiO2.http://www.sciencedirect.com/science/article/pii/S1110016816301247Mixed convectionVertical channelNanoliquidsHeat generationDirichletNeumannRobin boundary conditions |
| spellingShingle | Nur Asiah Mohd Makhatar P.G. Siddheshwar Habibis Saleh Ishak Hashim Oberbeck–Boussinesq free convection of water based nanoliquids in a vertical channel using Dirichlet, Neumann and Robin boundary conditions on temperature Alexandria Engineering Journal Mixed convection Vertical channel Nanoliquids Heat generation Dirichlet Neumann Robin boundary conditions |
| title | Oberbeck–Boussinesq free convection of water based nanoliquids in a vertical channel using Dirichlet, Neumann and Robin boundary conditions on temperature |
| title_full | Oberbeck–Boussinesq free convection of water based nanoliquids in a vertical channel using Dirichlet, Neumann and Robin boundary conditions on temperature |
| title_fullStr | Oberbeck–Boussinesq free convection of water based nanoliquids in a vertical channel using Dirichlet, Neumann and Robin boundary conditions on temperature |
| title_full_unstemmed | Oberbeck–Boussinesq free convection of water based nanoliquids in a vertical channel using Dirichlet, Neumann and Robin boundary conditions on temperature |
| title_short | Oberbeck–Boussinesq free convection of water based nanoliquids in a vertical channel using Dirichlet, Neumann and Robin boundary conditions on temperature |
| title_sort | oberbeck boussinesq free convection of water based nanoliquids in a vertical channel using dirichlet neumann and robin boundary conditions on temperature |
| topic | Mixed convection Vertical channel Nanoliquids Heat generation Dirichlet Neumann Robin boundary conditions |
| url | http://www.sciencedirect.com/science/article/pii/S1110016816301247 |
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