Free radially expanding liquid sheet in air: time- and space-resolved measurement of the thickness field
| Autor: | Clara Vernay, Christian Ligoure, Laurence Ramos |
|---|---|
| Přispěvatelé: | Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2015 |
| Předmět: |
[PHYS.PHYS.PHYS-FLU-DYN]Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn]
Materials science Spacetime Mechanical Engineering Drop (liquid) Fluid Dynamics (physics.flu-dyn) Liquid drop FOS: Physical sciences Physics - Fluid Dynamics Mechanics Condensed Matter - Soft Condensed Matter Condensed Matter Physics Collision Drop impact Physics::Fluid Dynamics Azimuth Surface tension Mechanics of Materials Temporal resolution Soft Condensed Matter (cond-mat.soft) [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] |
| Zdroj: | Journal of Fluid Mechanics Journal of Fluid Mechanics, Cambridge University Press (CUP), 2015, 764, pp.428-444. ⟨10.1017/jfm.2014.714⟩ |
| ISSN: | 1469-7645 0022-1120 |
| DOI: | 10.1017/jfm.2014.714 |
| Popis: | The collision of a liquid drop against a small target results in the formation of a thin liquid sheet that extends radially until it reaches a maximum diameter. The subsequent retraction is due to the air-liquid surface tension. We have used a time- and space-resolved technique to measure the thickness field of this class of liquid sheet, based on the grey level measurement of the image of a dyed liquid sheet recorded using a fast camera. This method enables a precise measurement of the thickness in the range $(10-450) \, \mathrm{\mu m}$, with a temporal resolution equal to that of the camera. We have measured the evolution with time since impact, $t$, and radial position, $r$, of the thickness, $h(r,t)$, for various drop volumes and impact velocities. Two asymptotic regimes for the expansion of the sheet are evidenced. The scalings of the thickness with $t$ and $r$ measured in the two regimes are those that were predicted in \citet{Rozhkov2004} fort the short-time regime and \citet{Villermaux2011} for the long time regime, but never experimentally measured before. Interestingly, our experimental data also evidence the existence of a maximum of the film thickness $h_{\rm{max}}(r)$ at a radial position $r_{\rm{h_{max}}}(t)$ corresponding to the crossover of these two asymptotic regimes. The maximum moves with a constant velocity of the order of the drop impact velocity, as expected theoretically. Thanks to our visualization technique, we also evidence an azimuthal thickness modulation of the liquid sheets. Comment: accepted for publication in Journal of Fluid Mechanics |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|