The role of the difference in bed elevations in the main-river (ΔzMR) and the tributary (ΔzT) at their entrance to a 90° straight-channel confluence is studied numerically using a 3D finite-volume model. Three characteristic hydrological scenarios with DR = QMR/Qtot = {0.250, 0.583, 0.750} (where QMR and Qtot are flow discharges in the main-river upstream and downstream of the confluence, respectively) are analysed in nine confluence layouts having ΔzMR/hd ε[0.10, 0.50] and ΔzT/hd ε[0.10, 0.50] (where hd stands for the flow depth in the deeper channel at the confluence). It is found that the presence of the bed-step in the main river: 1) does not affect the flow and bed shear stress distributions for DR = 0.250, 2) causes inclination of the recirculation zone and reduces its size for DR > 0.5, 3) favours conditions for the bed-load transport both in and far downstream of the confluence when DR ≠ 0.750 regardless of the ΔzT-value.
Source:
River Flow - Proceedings of the International Conference on Fluvial Hydraulics, RIVER FLOW 2016, 2016, 1616-1625
TY - CONF
AU - Đorđević, Dejana
AU - Stojnić, Ivan
PY - 2016
UR - https://grafar.grf.bg.ac.rs/handle/123456789/748
AB - The role of the difference in bed elevations in the main-river (ΔzMR) and the tributary (ΔzT) at their entrance to a 90° straight-channel confluence is studied numerically using a 3D finite-volume model. Three characteristic hydrological scenarios with DR = QMR/Qtot = {0.250, 0.583, 0.750} (where QMR and Qtot are flow discharges in the main-river upstream and downstream of the confluence, respectively) are analysed in nine confluence layouts having ΔzMR/hd ε[0.10, 0.50] and ΔzT/hd ε[0.10, 0.50] (where hd stands for the flow depth in the deeper channel at the confluence). It is found that the presence of the bed-step in the main river: 1) does not affect the flow and bed shear stress distributions for DR = 0.250, 2) causes inclination of the recirculation zone and reduces its size for DR > 0.5, 3) favours conditions for the bed-load transport both in and far downstream of the confluence when DR ≠ 0.750 regardless of the ΔzT-value.
PB - CRC Press/Balkema
C3 - River Flow - Proceedings of the International Conference on Fluvial Hydraulics, RIVER FLOW 2016
T1 - On the combined effect of bed elevation discordances in the main-river and the tributary in 90° straight-channel confluences
EP - 1625
SP - 1616
UR - https://hdl.handle.net/21.15107/rcub_grafar_748
ER -
@conference{
author = "Đorđević, Dejana and Stojnić, Ivan",
year = "2016",
abstract = "The role of the difference in bed elevations in the main-river (ΔzMR) and the tributary (ΔzT) at their entrance to a 90° straight-channel confluence is studied numerically using a 3D finite-volume model. Three characteristic hydrological scenarios with DR = QMR/Qtot = {0.250, 0.583, 0.750} (where QMR and Qtot are flow discharges in the main-river upstream and downstream of the confluence, respectively) are analysed in nine confluence layouts having ΔzMR/hd ε[0.10, 0.50] and ΔzT/hd ε[0.10, 0.50] (where hd stands for the flow depth in the deeper channel at the confluence). It is found that the presence of the bed-step in the main river: 1) does not affect the flow and bed shear stress distributions for DR = 0.250, 2) causes inclination of the recirculation zone and reduces its size for DR > 0.5, 3) favours conditions for the bed-load transport both in and far downstream of the confluence when DR ≠ 0.750 regardless of the ΔzT-value.",
publisher = "CRC Press/Balkema",
journal = "River Flow - Proceedings of the International Conference on Fluvial Hydraulics, RIVER FLOW 2016",
title = "On the combined effect of bed elevation discordances in the main-river and the tributary in 90° straight-channel confluences",
pages = "1625-1616",
url = "https://hdl.handle.net/21.15107/rcub_grafar_748"
}
Đorđević, D.,& Stojnić, I.. (2016). On the combined effect of bed elevation discordances in the main-river and the tributary in 90° straight-channel confluences. in River Flow - Proceedings of the International Conference on Fluvial Hydraulics, RIVER FLOW 2016
CRC Press/Balkema., 1616-1625.
https://hdl.handle.net/21.15107/rcub_grafar_748
Đorđević D, Stojnić I. On the combined effect of bed elevation discordances in the main-river and the tributary in 90° straight-channel confluences. in River Flow - Proceedings of the International Conference on Fluvial Hydraulics, RIVER FLOW 2016. 2016;:1616-1625.
https://hdl.handle.net/21.15107/rcub_grafar_748 .
Đorđević, Dejana, Stojnić, Ivan, "On the combined effect of bed elevation discordances in the main-river and the tributary in 90° straight-channel confluences" in River Flow - Proceedings of the International Conference on Fluvial Hydraulics, RIVER FLOW 2016 (2016):1616-1625,
https://hdl.handle.net/21.15107/rcub_grafar_748 .
