Flow characterization of an attraction channel as entrance to fishways
Article first published online: 12 JUL 2010
Copyright © 2010 John Wiley & Sons, Ltd.
River Research and Applications
Volume 27, Issue 10, pages 1290–1297, December 2011
How to Cite
Green, T. M., Lindmark, E. M., Lundström, T. S. and Gustavsson, L. H. (2011), Flow characterization of an attraction channel as entrance to fishways. River Res. Applic., 27: 1290–1297. doi: 10.1002/rra.1426
- Issue published online: 21 NOV 2011
- Article first published online: 12 JUL 2010
- Manuscript Accepted: 7 MAY 2010
- Manuscript Revised: 23 APR 2010
- Manuscript Received: 16 NOV 2009
- Swedish Energy Agency
- National Board of Fisheries
- Swedish Environmental Protection Agency
- attraction water;
The flow field inside and downstream of an open channel placed near the surface of a free flow (such as the tail water of a turbine) is characterized in detail. The channel cross-section is U-shaped and in the downstream end is placed a ramp on the bottom which accelerates the flow passing through the channel. This flow is intended to catch the attention of fish and improve their entrance to fishways, which has also been successfully demonstrated in field tests.
The flow through the channel is subcritical and the ramp thus blocks some water from passing through. To find the optimum vertical position of the channel, a down-scaled model channel is placed in a water flume and flow fields in vertical planes directed along the flow are visualized using particle image velocimetry. Results show that increasing the depth over the ramp has little effect on the maximum velocity while it makes the accelerated water more perceptible downstream the channel. This will most likely improve the channel's ability to attract fish. It is also shown that a recirculation zone is formed in the channel for the small depths tested. Finally, it is shown that a modest tilt of the channel will not affect the flow field in any significant way. Copyright © 2010 John Wiley & Sons, Ltd.