University of Roorkee, Roorkee.
This paper reports the experimental studies conducted to investigate the effect of the angle of off-take on sediment distribution in channels. The main channel flume was 3 ft. (0.9m.) wide and 20 ft. (6 m.) long and the off-take channel was 15 in. (38 cm.) wide. Five different off-take angles 30°, 60°, 90°, 120° and 150° were studied with a fixed quantity of sediment fed at the head of the parent channel for three channel discharges. At very low discharge when the sediment movement was insignificant, red beads were used to get an idea of sediment distribution pattern.
It was found that the 30° off-take angle was the most efficient in comparison with the other angles studied. It was also observed that the sediment shared by the off-take channel was not in proportion to the quantity of water allowed in the off-take. In all the cases, the sediment share in off-take was more than the discharge shared by the off-take. The existence of a centrifugal force at the off-take has been verified which was least for the angle of 30° at 10 per cent discharge of the parent channel.
