Environmental Evaluation of Denil Type Fishway

Flow pattern in a fish way has an effective role in providing a proper and safe passage for absorbing of fishes. High turbulence flow can be considered as a reductive factor of fish velocity and by causing damages to them leads in delay in raising the fishes or even dam their movement through the fish way. In this research, applying a combinatorial bi approach, hydraulics and biologic features of the fish way is analyzed and investigated. Velocity abilities and fish swimming power are used as an index for selecting optimized fish way. Toward this end Denil frame was changed in 30, 45 and 60 degree for investigating turbulence pattern of the flow using Flow-3D model. After comparison of numerical results and previous environmental studies about swimming power of fishes, the optimized fish way was selected. The results indicate that Denil fish way with 20 percent longitude slope and frame angle of 45 degree has higher accordance with swimming power of fishes especially rainbow Salmon in teenager, mature and pregnant mature ages.