عنوان مقاله [English]
In this study, the characteristics of the hydraulic jump on semi cylindrical rough bed a diverging stilling basin has investigated experimentally. The experiments have done with the walls diverging angles of 0, 2, 4, 6 and 8 degree for six different Froude numbers. Total of 200 tests were performed within the range of 5 to 8 Froude numbers. The relative depth reduction of jump for the angles of 0, 2, 4, 6 and 8 degrees have obtained 10.5, 17.7, 22, 26 and 26.2 percent respectively. The average reduction of length jump for the angles of 0, 2, 4, 6 and 8 degrees with the rough bed have obtained 47.9, 57.4, 59.9 ,65.9, and 68.2 percent respectively and in the optimal case (C2.2D) the reduction of length jump is 75 percent. The divergence of a basin without roughness effect also has influenced on reducing the relative length of jump about 37 to 47 percent and the relative length of jump are directly related to the angle of a divergence basin.