Barchan Dunes Cruising Dune-Size Obstacles

Author(s)

Assis, W. R. ; Borges, D. S. ; Franklin, E. M.

• Document type: Journal article
• Source: Geophysical Research Letters; v. 50, n. 14, p. 7-pg., 2023-07-28.

Abstract

We investigate the behavior of subaqueous barchans reaching dune-size obstacles by carrying out experiments where we varied the obstacle shape and size, the flow strength, and the grains' properties. We found that a subaqueous barchan can pass over or bypass a dune-size obstacle, or even be blocked, with some intermediate situations. In the bypass cases, the original barchan can split in two or more bedforms, redistributing sand in space. Finally, we propose a classification map in which the barchan behavior depends basically on two dimensionless parameters. Our results represent a step toward understanding how barchans behave in the presence of large obstacles, such as retaining walls, tubes and bridge pillars. (AU)

• FAPESP's process: 18/14981-7 - Modeling of dense granular flows: experiments, numerical simulations and stability analyses
• Grantee: Erick de Moraes Franklin
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2
• FAPESP's process: 19/10239-7 - Bed-load instabilities: granular dynamics and interaction with the fluid flow
• Grantee: Willian Righi Assis
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 22/01758-3 - Turbulent flow interacting with dense granular media: perturbations on the flow structure
• Grantee: Danilo da Silva Borges
• Support Opportunities: Scholarships in Brazil - Post-Doctoral