title: Micrometric granular ripple patterns in a capillary tube.
abstract: The oscillatory motion of a fluid carrying micron-sized particles inside a capillary tube is investigated experimentally. It is found that initially uniformly distributed particles can segregate and accumulate to form regularly spaced micron-sized particle clusters. The wavelength of the microclusters is compared to data for macroscale sand-ripple patterns and found to obey the same universal scaling as these. A dimensional analysis is performed that confirms the universality of the experimentally observed scaling. The experimental data for the microripple clusters further suggest the existence of a minimum particle length scale for which patterns can form and below which the Brownian motion associated with the molecules of the matrix fluid inhibits pattern formation.
authors: Laboratoire de Mécanique de Lille UMR CNRS 8107, Bd Paul Langevin, 59655 Villeneuve d'Ascq, France.
authors: F
authors: F
authors: Zoueshtiagh
authors: P J
authors: PJ
authors: Thomas
authors: V
authors: V
authors: Thomy
authors: A
authors: A
authors: Merlen