3.4. Flow over a single V-shaped sharp crested weir
Studies on the single V-shaped sharp crested weir were carried out at the Water Resources and Environmental Engineering Laboratory, University of Oulu, Finland in 1999 on a straight zero-sloped channel with several discharges and heads (Fig. 14). Zero slope was chosen because flow pattern was to be observed only very close to the weir.
Figure 14. The single V-shaped sharp-crested weir at the Water Resources and Environmental Engineering Laboratory.
The flume width in the studies was 600 mm, and the length of the flume was about 7 300 millimeters. Water was taken into the model from the water circulation system of the experimental hall. The lower water depth was controlled by an adjustable weir. The weir was applied in the middle part of the flume to establish uniform flow conditions both below and above the weir. The height of the weir, measured from the bottom to the lowest point of the V-notch, was 280 mm, and the opening angle was 90° (Fig. 15).
Heads were measured in these studies using a gauge, and velocities were measured with a four-hole probe that was developed at the T. Blench Hydraulic Laboratory, University of Alberta, Canada (Wu et al. 1999. Velocities were measured at the middle of the opening and in the side area at a few points. Discharges were measured by a Thompson weir.
