Preferential Concentration of Particles in Forced Turbulent Flows: Effects of Gravity
The impact of gravity on the particle preferential concentration is investigated by direct numerical simulations in an Eulerian–Lagrangian framework for a large range of Stokes numbers <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline">&...
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MDPI AG
2023-03-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/16/6/2910 |
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| author | Guodong Gai Olivier Thomine Abdellah Hadjadj Sergey Kudriakov Anthony Wachs |
| author_facet | Guodong Gai Olivier Thomine Abdellah Hadjadj Sergey Kudriakov Anthony Wachs |
| author_sort | Guodong Gai |
| collection | DOAJ |
| description | The impact of gravity on the particle preferential concentration is investigated by direct numerical simulations in an Eulerian–Lagrangian framework for a large range of Stokes numbers <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub><mo>=</mo><mn>0.01</mn><mo>∼</mo><mn>4</mn></mrow></semantics></math></inline-formula>. For particles with small Stokes numbers such as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub><mo>=</mo><mn>0.01</mn></mrow></semantics></math></inline-formula>, the gravity has minor effects on the particle spatial distribution in the turbulence. With increasing <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub></mrow></semantics></math></inline-formula>, stripped structures of the high number density of particles appear and expand along the gravity direction. Different evaluation methods of particle preferential concentration are discussed such as the spatial distribution, the box index, and the probability density function. The number density of particles in the accumulating regions reduced under the influence of gravity. The reduction becomes prominent for the particle cloud at Stokes number <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub><mo>≈</mo><mn>1</mn></mrow></semantics></math></inline-formula>, especially in the clusters of high particle number density. For large Stokes number <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub></mrow></semantics></math></inline-formula>, the slip velocity significantly increases due to the particle gravity. Due to the gravity, the particle concentration reduces globally, particularly in the low vorticity regions. For the Stokes number range explored in this paper, gravity has a considerable impact on the particle-turbulence interaction. |
| first_indexed | 2024-03-11T06:37:00Z |
| format | Article |
| id | doaj.art-91ab9e41526c451ab5290a5fda27b094 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-11T06:37:00Z |
| publishDate | 2023-03-01 |
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| series | Energies |
| spelling | doaj.art-91ab9e41526c451ab5290a5fda27b0942023-11-17T10:52:40ZengMDPI AGEnergies1996-10732023-03-01166291010.3390/en16062910Preferential Concentration of Particles in Forced Turbulent Flows: Effects of GravityGuodong Gai0Olivier Thomine1Abdellah Hadjadj2Sergey Kudriakov3Anthony Wachs4Department of Mathematics, University of British Columbia, Vancouver, BC V6T 1Z2, CanadaINSA, CORIA UMR-6614 CNRS, University of Normandy, 76000 Rouen, FranceINSA, CORIA UMR-6614 CNRS, University of Normandy, 76000 Rouen, FranceService de Thermo-Hydraulique et de Mécanique des Fluides, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, FranceDepartment of Mathematics, University of British Columbia, Vancouver, BC V6T 1Z2, CanadaThe impact of gravity on the particle preferential concentration is investigated by direct numerical simulations in an Eulerian–Lagrangian framework for a large range of Stokes numbers <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub><mo>=</mo><mn>0.01</mn><mo>∼</mo><mn>4</mn></mrow></semantics></math></inline-formula>. For particles with small Stokes numbers such as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub><mo>=</mo><mn>0.01</mn></mrow></semantics></math></inline-formula>, the gravity has minor effects on the particle spatial distribution in the turbulence. With increasing <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub></mrow></semantics></math></inline-formula>, stripped structures of the high number density of particles appear and expand along the gravity direction. Different evaluation methods of particle preferential concentration are discussed such as the spatial distribution, the box index, and the probability density function. The number density of particles in the accumulating regions reduced under the influence of gravity. The reduction becomes prominent for the particle cloud at Stokes number <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub><mo>≈</mo><mn>1</mn></mrow></semantics></math></inline-formula>, especially in the clusters of high particle number density. For large Stokes number <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>S</mi><msub><mi>t</mi><mi>η</mi></msub></mrow></semantics></math></inline-formula>, the slip velocity significantly increases due to the particle gravity. Due to the gravity, the particle concentration reduces globally, particularly in the low vorticity regions. For the Stokes number range explored in this paper, gravity has a considerable impact on the particle-turbulence interaction.https://www.mdpi.com/1996-1073/16/6/2910gravity effectincompressible flowparticle-turbulence interactionpreferential concentrationstokes number |
| spellingShingle | Guodong Gai Olivier Thomine Abdellah Hadjadj Sergey Kudriakov Anthony Wachs Preferential Concentration of Particles in Forced Turbulent Flows: Effects of Gravity Energies gravity effect incompressible flow particle-turbulence interaction preferential concentration stokes number |
| title | Preferential Concentration of Particles in Forced Turbulent Flows: Effects of Gravity |
| title_full | Preferential Concentration of Particles in Forced Turbulent Flows: Effects of Gravity |
| title_fullStr | Preferential Concentration of Particles in Forced Turbulent Flows: Effects of Gravity |
| title_full_unstemmed | Preferential Concentration of Particles in Forced Turbulent Flows: Effects of Gravity |
| title_short | Preferential Concentration of Particles in Forced Turbulent Flows: Effects of Gravity |
| title_sort | preferential concentration of particles in forced turbulent flows effects of gravity |
| topic | gravity effect incompressible flow particle-turbulence interaction preferential concentration stokes number |
| url | https://www.mdpi.com/1996-1073/16/6/2910 |
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