Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
MORPHOLOGY OF SUBAQUEOUS BARCHAN DUNES IN TURBULENT SHEAR FLOW
Submission Author:
Carlos Azael Alvarez , SP
Co-Authors:
Carlos Azael Alvarez, Erick de Moraes Franklin
Presenter: Carlos Azael Alvarez
doi://10.26678/ABCM.ENCIT2018.CIT18-0006
Abstract
The present paper reports the formation of subaqueous barchan dunes by analyzing the temporal evolution of their main geometrical characteristics (width W and length L). After a certain time, the dunes reach an equilibrium state and it is possible to study the relation between W versus L, and the dependence of the dune velocity on L. The barchan dunes were formed from round glass and zirconium beads. An initial conical heap of beads was placed on the bottom wall of a rectangular channel and it was entrained by a water turbulent flow. The evolution of the dunes was filmed with a charge coupled device camera placed above the channel and mounted on a traveling system. Our results show that after a characteristic time the dune shape does not change anymore and it travels at a roughly constant velocity. Once the equilibrium state is reached, W and L are measured, showing linear dependence. Furthermore, we show that the dune velocity V d scales with the inverse of the dune length.
Keywords
granular matter, transport of particles, bedload, barchan dunes
