Inertial Screening in Sedimentation
| Autor: | Segre, P. N. |
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| Rok vydání: | 2007 |
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| Druh dokumentu: | Working Paper |
| Popis: | We use particle image velocimetry to measure the sedimentation dynamics of a semi-dilute suspension of non-Brownian spheres at Reynolds numbers, $0.001\le Re\le 2.3$, extending from the Stokes to the moderately inertial regime. We find that the onset of inertial corrections to Stokes sedimentation occurs when the inertial screening length $l=a/Re$ becomes similar to the Stokes sedimentation length $\xi_0$, at $Re_c= a/\xi_0\approx 0.05$. For $Re>Re_c$, inertial screening significantly reduces both the magnitude and spatial extent of the particle velocity fluctuations. A modified Hinch force balance model connects the fluctuation magnitudes $\sigma_V/V$ to the correlation sizes $\xi$. Comment: 9 pages, 4 figures |
| Databáze: | arXiv |
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