The Knudsen Paradox in Micro-Channel Poiseuille Flows with a Symmetric Particle
The Knudsen paradox—the non-monotonous variation of mass-flow rate with the Knudsen number—is a unique and well-established signature of micro-channel rarefied flows. A particle which is not of insignificant size in relation to the duct geometry can significantly alter the flow behavior when introdu...
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MDPI AG
2020-12-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/11/1/351 |
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| author | Ananda Subramani Kannan Tejas Sharma Bangalore Narahari Yashas Bharadhwaj Andreas Mark Gaetano Sardina Dario Maggiolo Srdjan Sasic Henrik Ström |
| author_facet | Ananda Subramani Kannan Tejas Sharma Bangalore Narahari Yashas Bharadhwaj Andreas Mark Gaetano Sardina Dario Maggiolo Srdjan Sasic Henrik Ström |
| author_sort | Ananda Subramani Kannan |
| collection | DOAJ |
| description | The Knudsen paradox—the non-monotonous variation of mass-flow rate with the Knudsen number—is a unique and well-established signature of micro-channel rarefied flows. A particle which is not of insignificant size in relation to the duct geometry can significantly alter the flow behavior when introduced in such a system. In this work, we investigate the effects of a stationary particle on a micro-channel Poiseuille flow, from continuum to free-molecular conditions, using the direct simulation Monte-Carlo (DSMC) method. We establish a hydrodynamic basis for such an investigation by evaluating the flow around the particle and study the blockage effect on the Knudsen paradox. Our results show that with the presence of a particle this paradoxical behavior is altered. The effect is more significant as the particle becomes large and results from a shift towards relatively more ballistic molecular motion at shorter geometrical distances. The need to account for combinations of local and non-local transport effects in modeling reactive gas–solid flows in confined geometries at the nano-scale and in nanofabrication of model pore systems is discussed in relation to these results. |
| first_indexed | 2024-03-10T13:35:56Z |
| format | Article |
| id | doaj.art-8860cd3cf9f64cb9868a9c5298778d6f |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T13:35:56Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-8860cd3cf9f64cb9868a9c5298778d6f2023-11-21T07:33:49ZengMDPI AGApplied Sciences2076-34172020-12-0111135110.3390/app11010351The Knudsen Paradox in Micro-Channel Poiseuille Flows with a Symmetric ParticleAnanda Subramani Kannan0Tejas Sharma Bangalore Narahari1Yashas Bharadhwaj2Andreas Mark3Gaetano Sardina4Dario Maggiolo5Srdjan Sasic6Henrik Ström7Department of Mechanics and Maritime Sciences, Division of Fluid Dynamics, Chalmers University of Technology, 412 96 Göteborg, SwedenDepartment of Mechanics and Maritime Sciences, Division of Fluid Dynamics, Chalmers University of Technology, 412 96 Göteborg, SwedenDepartment of Mechanics and Maritime Sciences, Division of Fluid Dynamics, Chalmers University of Technology, 412 96 Göteborg, SwedenFraunhofer-Chalmers Research Centre, 412 88 Göteborg, SwedenDepartment of Mechanics and Maritime Sciences, Division of Fluid Dynamics, Chalmers University of Technology, 412 96 Göteborg, SwedenDepartment of Mechanics and Maritime Sciences, Division of Fluid Dynamics, Chalmers University of Technology, 412 96 Göteborg, SwedenDepartment of Mechanics and Maritime Sciences, Division of Fluid Dynamics, Chalmers University of Technology, 412 96 Göteborg, SwedenDepartment of Mechanics and Maritime Sciences, Division of Fluid Dynamics, Chalmers University of Technology, 412 96 Göteborg, SwedenThe Knudsen paradox—the non-monotonous variation of mass-flow rate with the Knudsen number—is a unique and well-established signature of micro-channel rarefied flows. A particle which is not of insignificant size in relation to the duct geometry can significantly alter the flow behavior when introduced in such a system. In this work, we investigate the effects of a stationary particle on a micro-channel Poiseuille flow, from continuum to free-molecular conditions, using the direct simulation Monte-Carlo (DSMC) method. We establish a hydrodynamic basis for such an investigation by evaluating the flow around the particle and study the blockage effect on the Knudsen paradox. Our results show that with the presence of a particle this paradoxical behavior is altered. The effect is more significant as the particle becomes large and results from a shift towards relatively more ballistic molecular motion at shorter geometrical distances. The need to account for combinations of local and non-local transport effects in modeling reactive gas–solid flows in confined geometries at the nano-scale and in nanofabrication of model pore systems is discussed in relation to these results.https://www.mdpi.com/2076-3417/11/1/351DSMCKnudsen minimumKnudsen paradoxmicro-channelPoiseuille flowrarefied flows |
| spellingShingle | Ananda Subramani Kannan Tejas Sharma Bangalore Narahari Yashas Bharadhwaj Andreas Mark Gaetano Sardina Dario Maggiolo Srdjan Sasic Henrik Ström The Knudsen Paradox in Micro-Channel Poiseuille Flows with a Symmetric Particle Applied Sciences DSMC Knudsen minimum Knudsen paradox micro-channel Poiseuille flow rarefied flows |
| title | The Knudsen Paradox in Micro-Channel Poiseuille Flows with a Symmetric Particle |
| title_full | The Knudsen Paradox in Micro-Channel Poiseuille Flows with a Symmetric Particle |
| title_fullStr | The Knudsen Paradox in Micro-Channel Poiseuille Flows with a Symmetric Particle |
| title_full_unstemmed | The Knudsen Paradox in Micro-Channel Poiseuille Flows with a Symmetric Particle |
| title_short | The Knudsen Paradox in Micro-Channel Poiseuille Flows with a Symmetric Particle |
| title_sort | knudsen paradox in micro channel poiseuille flows with a symmetric particle |
| topic | DSMC Knudsen minimum Knudsen paradox micro-channel Poiseuille flow rarefied flows |
| url | https://www.mdpi.com/2076-3417/11/1/351 |
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