| dc.description.abstract | Fishways provide a better environmental surrounds to streams and rivers that were intercepted with weirs or dams. It is achieved providing the migration of fish through these systems. Fish swim capabilities correlated to hydraulic and structural parameters are the key of design a good fishway. Velocity, dissipation energy and Reynolds shear stress are hydraulic parameters necessaries to assessment the fishways in terms of capability to be a good ambience to fishes swim. Making a good appraisal of the distribution of velocity through a tank is important, especially for fish with limited swim capability. Critical swimming speed is a standard measurement to assess swimming capabilities of different species of fishes based on its fatigue using time of exposure for different velocities. The value of flow velocity on a fishway should not be above the animal resistance. For this study, the threshold velocity considered is 1.3m/s or 4.3ft/s. Further velocity threshold, the fish travel should be done with acceptable values of power dissipation. Vertical slots ladder fish were used and 191 W/m³ or 5.41 W/ft³ is the power dissipation threshold for this specific fishway. The third and last threshold used as reference was of 500N/m² or 46.5N/ft² for Reynolds shear stress. Using an experimental scale model, fishway with vertical slots through a channel this study aim analyse velocity distribution, power dissipation and Reynolds shear stress. These were done with discharges of 35, 40, 45, 50 and 55 m³/h on scale model (i.e. range of 0.34 to 0.54 cfs) or, with no scale, discharges of 1.50, 1.71, 1.93, 2.14 and 2.35 m³/s (i.e. range of 53 to 83 cfs). Besides that, longitudinal slopes were of 6, 8, 10 and 12%. All data were collected, prepared and analyzed, providing support to compare hydraulic parameters on a tank for different discharges and slopes, given enough to achieve the evaluation of fish travel efficiency. An finite element mathematical simulation was prepared and was ran at Flow3D software, developed by FlowScience, in accordance with the physical experiment results and it provided consistence for future experiments at design variations of fishways. | |
