Geometrically Resolved Simulation of Upstream Migrating Antidune Formation and Propagation

Kemmler S, Schwarzmeier C, Rettinger C, Plewinski J, Núñez-González F, Köstler H, Rüde U, Vowinckel B (2023)

Publication Type: Conference contribution, Conference Contribution

Publication year: 2023

Event location: Wien

Abstract

Periodic structures developed at the interface between fluid flows and granular beds in motion are known as bedforms. Among the different types of bedforms in unidirectional free-surface flows, upstream-migrating antidunes in supercritical or near critical flows are perhaps the most striking features, given their apparently counterintuitive movement in opposite direction to the main flow. Analyzing the mechanisms involved in the formation and propagation of antidunes is necessary to understand their effects on channel roughness, sediment transport capacity and the turbulent flow field of streams, and is also crucial to identify the sedimentological footprint of antidunes for the reconstruction of paleohydraulic flows. However, difficulties to perform flow and sediment transport measurements in laboratory and field under near critical or supercritical flow conditions have precluded a deeper understanding of antidunes. In this regard,  simulations using geometrically resolved particles carried out on increasingly powerful supercomputers, offer a viable methodological alternative. Such massively parallelized simulations generate highly resolved flow field data and particle trajectories to analyze the antidune dynamics. These data are crucial to link preferential antidune wavelength, height, celerity and migration direction to a given flow condition. In this work, we present a method for the simulation of antidune formation and propagation with geometrically resolved particles. We use the lattice Boltzmann method (LBM) for the fluid dynamics simulation and extend it with a free-surface model [1], which is a prerequisite for the formation of antidunes. The particle interactions are modeled using a discrete element method with proper momentum exchange for the fluid-particle coupling [2] implemented in the waLBerla framework [3]. This approach allows for large scale antidune simulations consisting of thousands of particles. We aim to provide a direct comparison of our simulation results to the study of Pascal et al. [4], who have investigated the variability of antidune morphodynamics in natural gravel. We will show that our simulation approach is capable to reproduce the key features of antidunes and we will present first results on the antidune dynamics as well as fluid and particle statistics to better understand the mechanisms involved in the formation and propagation of antidunes. To the best of our knowledge, this is the first study in which upstream-migrating antidunes are successfully simulated with a high-resolution model.

[1] Schwarzmeier, C., & Rüde, U. (2022). Analysis and comparison of boundary condition variants in the free-surface lattice Boltzmann method. arXiv preprint arXiv:2207.13962.

[2] Rettinger, C., & Rüde, U. (2017). A comparative study of fluid-particle coupling methods for fully resolved lattice Boltzmann simulations. Computers & Fluids, 154, 74-89.

[3] https://www.walberla.net/

[4] Pascal, I., Ancey, C., & Bohorquez, P. (2021). The variability of antidune morphodynamics on steep slopes. Earth Surface Processes and Landforms, 46(9), 1750-1765

Authors with CRIS profile

Involved external institutions

Universitat Politècnica de Catalunya · BarcelonaTech (UPC) Spain (ES)

How to cite

APA:

Kemmler, S., Schwarzmeier, C., Rettinger, C., Plewinski, J., Núñez-González, F., Köstler, H.,... Vowinckel, B. (2023). Geometrically Resolved Simulation of Upstream Migrating Antidune Formation and Propagation. In Proceedings of the 40th IAHR World Congres. Wien, AT.

MLA:

Kemmler, Samuel, et al. "Geometrically Resolved Simulation of Upstream Migrating Antidune Formation and Propagation." Proceedings of the 40th IAHR World Congres, Wien 2023.

BibTeX: Download