Hydraulic performance of fish guidance structures with curved bars – Part 1: head loss assessment. Issue 5 (18th September 2020)

• Record Type: Journal Article
• Authors: Beck, Claudia; Albayrak, Ismail; Meister, Julian; Boes, Robert M.
• Is Part Of: Journal of hydraulic research. Volume 58:Issue 5(2020)
• Page Start: 807
• Page End: 818
• Publication Date: 2020-09-18
• Subjects: Curved-bar rack -- downstream fish migration -- fish guidance -- fish protection -- head loss -- louvre; Hydraulics -- Research -- Periodicals; Hydraulic engineering -- Periodicals; Hydraulic engineering; Electronic journals; Periodicals; 621.2
• DOI: 10.1080/00221686.2019.1671515
• Languages: English
• ISSNs: 0022-1686

Abstract

Abstract : The hydraulic performance of fish guidance structures such as louvres and angled bar racks is an important design criterion to achieve high fish guidance efficiencies with a minimum impact on hydropower production. The current geometrical designs of such structures result in high head losses and asymmetric turbine admission flow and hence need to be optimized. We therefore developed an innovative curved bar design for fish guidance structures and experimentally investigated different rack configurations in a laboratory flume. The present paper (Part I) focuses on the hydraulic performance of the novel curved-bar racks with regard to head losses, while in the companion paper (Part II) we report the results on the flow fields. The effects of the main rack angle, bar angle, bar spacing, bar depth, and top or/and bottom overlays were systematically studied. The curved bar shape leads to significantly lower head losses compared to straight bar shapes. An existing head loss prediction formula was extended to account for the new bar shape and the application of overlays.