Thermal Convection of an Ellis Fluid Saturating a Porous Layer with Constant Heat Flux Boundary Conditions
The present work analyzes the thermal instability of mixed convection in a horizontal porous channel that is saturated by a shear-thinning fluid following Ellis’ rheology. The fluid layer is heated from below by a constant heat flux and cooled from above by the same heat flux. The instability of suc...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-02-01
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| Series: | Fluids |
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| Online Access: | https://www.mdpi.com/2311-5521/8/2/54 |
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| author | Pedro Vayssière Brandão Michele Celli Antonio Barletta Stefano Lazzari |
| author_facet | Pedro Vayssière Brandão Michele Celli Antonio Barletta Stefano Lazzari |
| author_sort | Pedro Vayssière Brandão |
| collection | DOAJ |
| description | The present work analyzes the thermal instability of mixed convection in a horizontal porous channel that is saturated by a shear-thinning fluid following Ellis’ rheology. The fluid layer is heated from below by a constant heat flux and cooled from above by the same heat flux. The instability of such a system is investigated by means of a small-disturbances analysis and the resulting eigenvalue problem is solved numerically by means of a shooting method. It is demonstrated that the most unstable modes on the instability threshold are those with infinite wavelength and an analytical expression for such conditions is derived from an asymptotic analysis. Results show that the non-Newtonian character of the fluid has a destabilizing role. |
| first_indexed | 2024-03-11T08:50:35Z |
| format | Article |
| id | doaj.art-276c4b2de87b49a4b7911c958ce211c1 |
| institution | Directory Open Access Journal |
| issn | 2311-5521 |
| language | English |
| last_indexed | 2024-03-11T08:50:35Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fluids |
| spelling | doaj.art-276c4b2de87b49a4b7911c958ce211c12023-11-16T20:28:45ZengMDPI AGFluids2311-55212023-02-01825410.3390/fluids8020054Thermal Convection of an Ellis Fluid Saturating a Porous Layer with Constant Heat Flux Boundary ConditionsPedro Vayssière Brandão0Michele Celli1Antonio Barletta2Stefano Lazzari3Department of Industrial Engineering, Alma Mater Studiorum Università di Bologna, Viale Risorgimento 2, 40136 Bologna, ItalyDepartment of Industrial Engineering, Alma Mater Studiorum Università di Bologna, Viale Risorgimento 2, 40136 Bologna, ItalyDepartment of Industrial Engineering, Alma Mater Studiorum Università di Bologna, Viale Risorgimento 2, 40136 Bologna, ItalyDepartment of Architecture and Design, Polytechnic School, University of Genoa, Stradone S. Agostino 37, 16123 Genoa, ItalyThe present work analyzes the thermal instability of mixed convection in a horizontal porous channel that is saturated by a shear-thinning fluid following Ellis’ rheology. The fluid layer is heated from below by a constant heat flux and cooled from above by the same heat flux. The instability of such a system is investigated by means of a small-disturbances analysis and the resulting eigenvalue problem is solved numerically by means of a shooting method. It is demonstrated that the most unstable modes on the instability threshold are those with infinite wavelength and an analytical expression for such conditions is derived from an asymptotic analysis. Results show that the non-Newtonian character of the fluid has a destabilizing role.https://www.mdpi.com/2311-5521/8/2/54mixed convectionshear-thinning fluidsEllis model |
| spellingShingle | Pedro Vayssière Brandão Michele Celli Antonio Barletta Stefano Lazzari Thermal Convection of an Ellis Fluid Saturating a Porous Layer with Constant Heat Flux Boundary Conditions Fluids mixed convection shear-thinning fluids Ellis model |
| title | Thermal Convection of an Ellis Fluid Saturating a Porous Layer with Constant Heat Flux Boundary Conditions |
| title_full | Thermal Convection of an Ellis Fluid Saturating a Porous Layer with Constant Heat Flux Boundary Conditions |
| title_fullStr | Thermal Convection of an Ellis Fluid Saturating a Porous Layer with Constant Heat Flux Boundary Conditions |
| title_full_unstemmed | Thermal Convection of an Ellis Fluid Saturating a Porous Layer with Constant Heat Flux Boundary Conditions |
| title_short | Thermal Convection of an Ellis Fluid Saturating a Porous Layer with Constant Heat Flux Boundary Conditions |
| title_sort | thermal convection of an ellis fluid saturating a porous layer with constant heat flux boundary conditions |
| topic | mixed convection shear-thinning fluids Ellis model |
| url | https://www.mdpi.com/2311-5521/8/2/54 |
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