Document Type : Research Article
Authors
Water Engineering Faculty, Shahid Chamran University, Ahvaz, Khouzestan
Keywords
Main Subjects
In recent years, using of baffle sloped culverts is improved in order to energy dissipation and facility and improvement of fishes passage. In the present study, asymmetric shape w overflow is used as obstacles in Open Calvert. As spillway event angle two 40 degrees angle in 10 and 15 cm weir height to flume bottom were used.Experiments of present research are done in a steep flume with bottom width of 25 cm length that w-shaped spillways attached at about 5 km from the flume, and the distance between barriers, variable slope from 3 to 7.6 percent in different discharge was scheduled. In this study, three physical model including models with 30 obstacles of kind of asymmetric w shape spillway, with relative distance of 6/0 (λ=0.6), and a model with 15 barriers with relative distance of 1.2, and a model with 10 models with relative distance of 1.8, was setup. The results obtained from these experiments showed that by increasing the relative distance, Manning coefficient and Darcy-Weisbach coefficient is decreased, and also by increasing the slope, Manning and Darcy-Weisbach coefficient decreases. Based on the obtained results in the slope of 3%, Manning roughness coefficient, reaches from 0.065 on the 0.6 relative distance reaches to 0.048 in the 1.8 relative distance. The square root of the Darcy-Weisbach coefficient, in slope of 3%, in relative distance of 1.8, reaches from 0.87 to 0.65.
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