عنوان مقاله [English]
Abstract: The present research investigate experimental the head loss of flow energy throw the semi cylindrical wire-gates. The effective parameters on the studied system in forms of dimensionless parameters obtained by using Buckingham’s theory. The experiments were conducted in a rectangular flume with the length of 8m, width of 0.282m and height of 0.3m in Soil Conservation and Watershed Management Research Institute, using physical models with diameters 70, 120 and 160 mm in height of the opening between 0 until radius and differently discharging. The ratio of cylindrical structure diameter to channel width (D/B) was in the range of 0.25 to 0.57 and the Froude number was in range of 0.08 to 0.55. The results shows that in all angles which structure sets, dimension less parameter Hf/H cases curvature upstream and downstream with increasing Froude number and dimensionless parameter H/P increases, so that coefficient in both cases curvature upstream and downstream with increasing water depth upstream and dimension less parameter H/P Linearly decreases. Constant a (H/P) and Froude number, a dimensionless parameter Hf / H when the curvature is upstream semi cylindrical wire-gate due to the gradual contraction of flow lines and thus decrease the input is less than the curvature is downstream structure. Moreover, the result shows that in addition to the angle of semi cylindrical curvature to horizon line, structure diameter was affected on head loss amount.