Assessment of the point-wise approach for the Turbulent Settling of finite-size particles
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2025
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866913725723705344 |
|---|---|
| author | Battistaa, Francesco Chibbarob, Sergio Gualtieria, Paolo |
| author_facet | Battistaa, Francesco Chibbarob, Sergio Gualtieria, Paolo |
| contents | We study the settling of suspensions of relatively large particles with a diameter of the order of ten Kolmogorov scales and density slightly larger than the carrier fluid in statistically steady homogeneous isotropic turbulence. The particle-to-fluid density ratio is varied to obtain a wide range of Galileo numbers, which are the ratios between buoyancy and viscous forces. We analyse the problem through high-resolved one-way coupled direct numerical simulations where the particles are modeled as material points. The physical parameters are chosen in the same range used in recent particle-resolved simulations, against which we compare (PRS, [1, 2]). The results of the point-wise simulations are in good agreement with the PRS ones, showing a reduced settling speed for the range of parameters under investigation, relevant to suspensions settling in aqueous media, at volume fractions up to a few percent for density ratios order of one. Results are obtained neglecting the inter-particles and particle-fluid interactions while purposely including/not including the different forces (e.g. Stokes drag, added mass, lift force) in the particles' equations of motion to highlight their contributions respectively. At a high Galileo number, the mean settling velocity is only slightly affected by turbulent fluctuations, and it is the same obtained for the settling velocity of a single particle in a quiescent fluid. When the Galileo number is reduced, the settling velocity is progressively affected by turbulent fluctuations that cause a substantial decrease in the particle sedimentation speed. The present results are particularly relevant for applications. Point-wise models endowed with an accurate description of the hydrodynamic force are effective in capturing the particle settling speed and other higher-order statistics as demonstrated by direct comparison against particle-resolved simulations [1, 2]. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_06481 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Assessment of the point-wise approach for the Turbulent Settling of finite-size particles Battistaa, Francesco Chibbarob, Sergio Gualtieria, Paolo Fluid Dynamics 76T20 We study the settling of suspensions of relatively large particles with a diameter of the order of ten Kolmogorov scales and density slightly larger than the carrier fluid in statistically steady homogeneous isotropic turbulence. The particle-to-fluid density ratio is varied to obtain a wide range of Galileo numbers, which are the ratios between buoyancy and viscous forces. We analyse the problem through high-resolved one-way coupled direct numerical simulations where the particles are modeled as material points. The physical parameters are chosen in the same range used in recent particle-resolved simulations, against which we compare (PRS, [1, 2]). The results of the point-wise simulations are in good agreement with the PRS ones, showing a reduced settling speed for the range of parameters under investigation, relevant to suspensions settling in aqueous media, at volume fractions up to a few percent for density ratios order of one. Results are obtained neglecting the inter-particles and particle-fluid interactions while purposely including/not including the different forces (e.g. Stokes drag, added mass, lift force) in the particles' equations of motion to highlight their contributions respectively. At a high Galileo number, the mean settling velocity is only slightly affected by turbulent fluctuations, and it is the same obtained for the settling velocity of a single particle in a quiescent fluid. When the Galileo number is reduced, the settling velocity is progressively affected by turbulent fluctuations that cause a substantial decrease in the particle sedimentation speed. The present results are particularly relevant for applications. Point-wise models endowed with an accurate description of the hydrodynamic force are effective in capturing the particle settling speed and other higher-order statistics as demonstrated by direct comparison against particle-resolved simulations [1, 2]. |
| title | Assessment of the point-wise approach for the Turbulent Settling of finite-size particles |
| topic | Fluid Dynamics 76T20 |
| url | https://arxiv.org/abs/2503.06481 |