Laboratory Study of the Effect of Groyn on Lateral Intake Efficiency

Under low flow conditions, one of the major concerns in gravity intake from rivers is the low water intake efficiency. This occurs when the river thalweg lie too far from the intake area. In the present study, the effect of application of groyne at the opposite bank on intake flow efficiency is investigated using a laboratory flume The main channel of the flume was 30 m long, 1.5m wide with a 2.5 m short intake channel of a width of 60 em. The two channels were jointed to each other by angle of 60 degrees. Three different lengths of groynes under three flow discharge conditions were investigated experimentally. The experimental results were then compared with no groynes. The results showed that channel thalweg is developed near intake side of the main channel when the groyne is used. Furthermore, the results highlighted an increase in flow efficiency and a reduction in sediment intake when the groyne was employed.