Abstract
Open-channel beds show variations in the transverse direction due to the interaction between downstream flow, cross-stream flow, and bed topography, which may reduce the navigable width or endanger the foundations of structures. The reported preliminary laboratory study shows that a bubble screen can generate cross-stream circulation that redistributes velocities and hence, would modify the topography. In straight flow, the bubble-generated cross-stream circulation cell covers a spanwise extent of about four times the water depth and has maximum transverse velocities of about 0.2 ms¿1. In sharply curved flow, it is slightly weaker and narrower with a spanwise extent of about three times the flow depth. It shifts the counter-rotating curvature-induced cross-stream circulation cell in the inwards direction. Maximum bubble-generated cross-stream circulation velocities are of a similar order of magnitude to typical curvature-induced cross-stream circulation velocities in natural open-channel bends. The bubble screen technique is adjustable, reversible, and ecologically favorable. Detailed data on the 3D flow field in open-channel bends is provided, which can be useful for validation of numerical models
Original language | English |
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Pages (from-to) | 184-195 |
Journal | Journal of Hydraulic Engineering |
Volume | 134 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2008 |
Keywords
- hydraulic engineering
- channels
- hydrodynamics
- water flow
- bending
- redistribution
- velocity
- turbulence
- laboratory tests
- submerged vanes
- secondary flows
- alternate bars
- topography
- bends
- rivers