Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
ROLE OF DRAG FORCE IN GRANULAR SIZE SEGREGATION IN SEDIMENT TRANSPORT
Submission Author:
Jaime Gonzalez-Maya , SP
Co-Authors:
Jaime Gonzalez-Maya, Fernando David Cúñez, Erick de Moraes Franklin
Presenter: Jaime Gonzalez-Maya
doi://10.26678/ABCM.ENCIT2022.CIT22-0085
Abstract
Fluid-driven granular flows are usually found in nature, such as the transport of fine and coarse sediments at the bottom of rivers and the formation of sand dunes in deserts, and have been studied for a while; however, understanding their behavior remains a challenge. In this work, we develop numerical simulations by using an Eulerian-Lagrangian approach, where the fluid flow is solved by Computational Fluid Dynamics (CFD) and the particle interactions are computed by the Discrete Element Method (DEM), being the drag force, which computes the fluid-particles interactions, an important parameter that couples both methods. Thus, this study aims to test and validate different drag force correlations in order to analyze size segregation that coarse grains experience in a dense granular flow. To run the numerical simulations, we used a rectangular channel filled with grains of two different sizes, where, we imposed a Couette laminar fluid flow by moving the top wall of the channel. This induced the motion of particles by bedload, which consists in a thin moving layer in the surface of the granular bed, and creep, which corresponds to a larger layer underneath the bedload layer. To mimic a long infinitely river, we set periodic conditions at the inlet and outlet of the channel in the streamwise direction. Our preliminary results show that coarse grains segregate towards the bed surface from the creep layer, for which we plotted the trajectories of coarse particles over time for different fluid flows conditions. Besides, we analyze the influence of 3 different drag models in our simulations and how they affect the segregation rate. Finally, we also validate our simulations with experiments that have been running lately. Our results will lead us to understand the segregation behavior that may be found in more complex scenarios such as rock river beds
Keywords
Sediment Transport, size segregation, bed-load transport, drag model correlations.
