Gurobekken flume is located in the basement of the main hydraulic laboratory shared between SINTEF and NTNU in Trondheim, Norway. The flume is 3.8 meters wide, 2 meters deep and it has a length of 50 meters. The flume is straight, but has a natural gravel bed with complex topography. It is divided in three reaces, with a net mounted in the cross-sections between the reaches. The net prevents fish from passing between the reaches. It also creates a head loss, making the inflow velocity profile for each reach more uniform.
Measurements of water velocity in the flume
The bed levels for the most upstream section are shown with colours. Red is high level and blue is low level
The purpose of the present study was partly to investigate the accuracy of the CFD model to compute the water velocity in the flume. It was also investigated how fluctuating water levels would affect fish stranding. For this purpose, the flume is divided in three reaches. The different geometries of the reaches would test different stranding properties of the geometry.
Computational grid seen from above
Velocity vectors close to the bed for the most upstream reach with 140 liters/second
Horizontal velocities close to the water surface for the most upstream reach and 140 liters/second. Red is high velocity and blue is low velocity
For each section, three velocity profiles were taken, at three different discharges. One of the profiles was taken at the upstream boundary, providing inflow boundary conditions for the CFD model. The other two profiles were used for verification.
The CFD computations and most of the measurements were carried out by Beate Kohler as a part of her MSc thesis at the University of Stuttgart, Germany, with assistance from Hans-Petter Fjeldstad at SINTEF and Nils Reidar Olsen at NTNU.
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