Author(s): Lina Focht; Patrick Heneka

Linked Author(s):

Keywords: Turbulence; Velocity fluctuations; Vertical slot fishway; Acoustic doppler velocimetry; Ecohydraulic experiments

Abstract: Fish migration through vertical slot fishways (vsf) is affected by turbulence, which may support or hamper fish passage depending on its characteristics. Experimental research regarding fish response to turbulence in vsf requires a sequence of pools to produce typical flow patterns and turbulence in the slot. Hence, space demand of respective hydraulic models is high if model scale has to meet requirements of fish tests (up to 1:1 scale). In order to fulfill hydraulic requirements of an ecohydraulic study in a full-scale 2.5 m flume, we established a device of rotatable fins that enables the provision of different and defined velocity fluctuations in a vsf-slot without the demand for a sequence of pools or time-consuming modification of model set-up. We demonstrate the ability of the device to provide flow with low fluctuations, naturally occurring fluctuations as well as periodic large-scale fluctuations. For large scale periodic fluctuation, fins are periodically opened and closed at a set angle and frequency. The device enables frequent and rapid changes between scenarios, making it a promising tool for investigating fish response to different turbulence characteristics in vsf. The results of this study provide valuable insights into the use and (general) application of the device in laboratory flumes.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0145-cd

Year: 2023