Fluid inertia effects on the motion of small spherical bubbles or solid spheres in turbulent flows
| Autor: | Dominique Legendre, Zhentong Zhang, Rémi Zamansky |
|---|---|
| Přispěvatelé: | Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées |
| Rok vydání: | 2021 |
| Předmět: |
Drag coefficient
Mécanique des fluides media_common.quotation_subject Inertia Bubble dynamics 01 natural sciences [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] 010305 fluids & plasmas Physics::Fluid Dynamics symbols.namesake Stokes' law 0103 physical sciences 010306 general physics Stokes number media_common Added mass Physics Turbulence Mechanical Engineering Reynolds number Mechanics Condensed Matter Physics Mechanics of Materials Drag Particle/fluid flow Isotropic turbulence symbols |
| Zdroj: | Journal of Fluid Mechanics Journal of Fluid Mechanics, Cambridge University Press (CUP), 2021, 921, pp.A4. ⟨10.1017/jfm.2021.475⟩ |
| ISSN: | 1469-7645 0022-1120 |
| DOI: | 10.1017/jfm.2021.475 |
| Popis: | International audience; In this paper we study finite particle Reynolds number effects up to Re p=50 on the dynamics of small spherical bubbles and solid particles in an isotropic turbulent flow. We consider direct numerical simulations of light pointwise particles with various expressions of the drag force to account for finite Re p and the type of particle. Namely, we consider the Stokes drag law, the Schiller and Neumann relation and the Mei law. We show that an effective Stokes number, based on the mean value of the drag coefficient to account for the inertial effects involved in the drag law, gives a quasi-self-similar evolution of the variances of the bubble acceleration and of the forces exerted on the particle. This allows us to provide a satisfactory prediction of these quantities using Tchen's theory at finite particle Reynolds number. Based on these relations, we can specify the conditions under which the total inertial force (sum of the added mass and the Tchen contributions) is negligible compared with the drag force. Thus, for particles of very small dimensions, the fluid inertia force is negligible, provided the density ratio is of order 1 or larger. However, when the particle inertia becomes consequential, the threshold value of the density ratio increases significantly. Although this corresponds to the limit of the validity of the model, this draws attention to the fact that, for large Stokes numbers, the added mass and fluid inertia forces could play a more important role than is usually attributed to them. |
| Databáze: | OpenAIRE |
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