Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
DYNAMICS OF BARCHAN FIELDS
Submission Author:
Willian Righi Assis , SP
Co-Authors:
Willian Righi Assis, Erick de Moraes Franklin
Presenter: Willian Righi Assis
doi://10.26678/ABCM.COBEM2019.COB2019-0164
Abstract
Barchan is a crescentic-shape dune, often organized in dune fields. When barchans are in a dune field, collisions play a significant role regulating the dynamics and sizes of barchans. The present work investigates the morphology and dynamics of barchan fields, starting with binary collisions and corridors with three and five subaqueous barchan dunes. The experimental setup consisted, basically, in water reservoir, centrifugal pumps, a closed-conduit channel where different piles of glass beads were poured, and a high-definition camera used to acquire images of the granular piles as they evolved to barchan dunes. Image processing is performed from a developing code. For binary collision, we observed an instability over the mass distribution of the dune due the final link between them. The number of total dunes, number of grains leaving target dune (as a mass loss), dimensionless relation of area, width and length of two dunes as well as a characteristic time were computed to understand the dunes interaction. We use different experimental parameters to show, statistically, the dynamics of binary collision. For fields of three and five barchans, the investigation started with morphological parameters over the dune fields. The tracking of grains that are arriving and leaving dunes in corridors is still a pending question to be investigated.
Keywords
barchan dunes, dune field, collision
