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Turbulent Flow near Vertical Angled Fish Screen |
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| Authors: | N Rajaratnam C Katopodis M A F Sadeque N Pokharel |
| Affiliation: | 1Dept. of Civil Engineering, Univ. of Alberta, Edmonton AB, Canada T6G 2W2 (corresponding author). E-mail: nrajaratnam@ualberta.ca 2Katopodis Ecohydraulics Ltd.; formerly, Freshwater Institute, Fisheries & Oceans Canada, 501 Univ. Crescent, Winnipeg MB, Canada R3T 2N6. 3Civil Design, BC Hydro, 6911 Southpoint Dr., Burnaby BC, Canada V3N 4X8. 4BPR Engineering Inc., 1100 Burloak Dr., Toronto ON, Canada L7L 6B2. |
| Abstract: | Mean and turbulent flow characteristics on the upstream and downstream sides of the screen in a flow diversion channel have important implications for operation and maintenance (e.g., sedimentation) and for assessing fish behavior related to flow turbulence. This technical note extends an earlier study on mean flow near screens to turbulence characteristics. Acoustic Doppler velocimeter was used to explore three-dimensional mean and turbulent flow characteristics on the upstream and downstream sides of vertical angled fish screens. The present study confirms the two-dimensional mean velocity observations of the previous experimental work and shows that the vertical mean velocities are less than 10% of the local magnitudes of longitudinal velocity and hence can be ignored. Horizontal components of the mean velocity on the downstream side of the screen were relatively small, but the turbulent velocity fluctuations were two to three times as intense as those measured on the upstream side. |
| Keywords: | Fish management Flow distribution Turbulence Hydraulic structures |