A two-dimensional double layer-averaged model of hyperconcentrated turbidity currents with non-Newtonian rheology
ORCID
- Alistair George Liam Borthwick: 0000-0001-6053-7764
Abstract
Hyperconcentrated turbidity currents typically display non-Newtonian characteristics that influence sediment transport and morphological evolution in alluvial rivers. However, hydro-sediment-morphological processes involving hyperconcentrated turbidity currents are poorly understood, with little known about the effect of the non-Newtonian rheology. The current paper extends a recent two-dimensional double layer-averaged model to incorporate non-Newtonian constitutive relations. The extended model is benchmarked against experimental and numerical data for cases including subaerial mud flow, subaqueous debris flow, and reservoir turbidity currents. The computational results agree well with observations for the subaerial mud flow and independent numerical simulations of subaqueous debris flow. Differences between the non-Newtonian and Newtonian model results become more pronounced in terms of propagation distance and sediment transport rate as sediment concentration increases. The model is then applied to turbidity currents in the Guxian Reservoir planned for middle Yellow River, China, which connects to a tributary featuring hyperconcentrated sediment-laden flow. The non-Newtonian model predicts slower propagation of turbidity currents and more significant bed aggradation at the confluence between the tributary Wuding River and the Yellow River in the reservoir than its Newtonian counterpart. This difference in model performance could be of considerable importance when optimizing reservoir operation schemes.
DOI
10.1016/j.ijsrc.2023.08.002
Publication Date
2023-01-01
Publication Title
International Journal of Sediment Research
Volume
38
Issue
6
ISSN
1001-6279
Embargo Period
2025-10-28
First Page
794
Last Page
810
Recommended Citation
Cao, Z., Sun, Y., Li, J., & Borthwick, A. (2023) 'A two-dimensional double layer-averaged model of hyperconcentrated turbidity currents with non-Newtonian rheology', International Journal of Sediment Research, 38(6), pp. 794-810. Available at: https://doi.org/10.1016/j.ijsrc.2023.08.002