Artículos de revistas
Intermittent Gravity-driven Flow Of Grains Through Narrow Pipes
Registro en:
Physica A: Statistical Mechanics And Its Applications. Elsevier Science Bv, v. 465, p. 725 - 741, 2017.
0378-4371
1873-2119
WOS:000386411700070
10.1016/j.physa.2016.08.071
Autor
Alvarez
Carlos A.; Franklin
Erick de Moraes
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Grain flows through pipes are frequently found in various settings, such as in pharmaceutical, chemical, petroleum, mining and food industries. In the case of size-constrained gravitational flows, density waves consisting of alternating high-and low-compactness regions may appear. This study investigates experimentally the dynamics of density waves that appear in gravitational flows of fine grains through vertical and slightly inclined pipes. The experimental device consisted of a transparent glass pipe through which different populations of glass spheres flowed driven by gravity. Our experiments were performed under controlled ambient temperature and relative humidity, and the granular flow was filmed with a high-speed camera. Experimental results concerning the length scales and celerities of density waves are presented, together with a one-dimensional model and a linear stability analysis. The analysis exhibits the presence of a long-wavelength instability, with the most unstable mode and a cut-off wavenumber whose values are in agreement with the experimental results. (C) 2016 Elsevier B.V. All rights reserved. 465 725 741 Ecuadorian government foundation SENESCYT [2013-AR2Q2850] FAPESP [2012/19562-6] CNPq [471391/2013-1] FAEPEX/UNICAMP [AP0008/2013, 519.292] Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)