Weirs and gates are hydraulic structures installed in canals, mainly for controlling the discharge.
Because of their existence, unfavorable influences regarding the downstream bed configurations
were recorded. This study experimentally explores the combined effect of simultaneous flow through
a hydraulic device consisting of a V-notch sharped weir with an inverted V-shaped gate, aiming to
minimize the downstream bed scour. Eighty-one runs were carried out using nine weir-gate models
with three different vertex angles. The tests were executed considering three upstream and three
downstream water depths. A V-notch weir with an angle of 120º was tested under similar hydraulic
conditions and was used for comparison. The results revealed that the length of backflow was
increased by the decrease in weir angle under a fixed 120° gate angle. The bed configurations
were sensitive to gate angle. The combined device showed a significant decrease in bed disturbances
regardless of the angles used compared to the traditional V-notch weir. Simple formulas were
developed to predict the scour parameters. |
