Large Eddy Simulation of ice-covered flows in a river bend

We investigate the impact of ice coverage on the secondary flow structures and the associated bed shear stresses in a river bend of the Red River in Fargo, North Dakota, United States using both field measurement and numerical simulation (Large Eddy Simulation). Acoustic Doppler Current Profiler (ADCP), Sontek M9, is employed to measure flow fields under ice-covered conditions (Feb/2021 and Feb/2022). Large-Eddy Simulation is performed to determine the three-dimensional flow structures using the input data from our field measurements, the United States Geological Survey, and North Dakota Water Commission. Our results show the impact of the ice cover is significant in changing the spatial arrangement of the secondary flow structures. In addition, the Turbulent Kinetic Energy is altered significantly near the bend apex as the result of the interaction between the turbulent flows and the ice cover, especially in regions near both banks. Our results show that ice coverage promote secondary flow structures to form across cross-sections. Our data suggests that the ice cover not only changes the local secondary flow structures but also the meandering patterns of large-scale flow structures in ice-covered rivers.