عنوان مقاله [English]
The discharge coefficient of labyrinth weirs increases with increasing the crest length within a certain width range. This study compares the discharge coefficient in two types of one-cycle triangular and trapezoidal labyrinth weirs. Experiments were conducted on a laboratory flume with length of 6, width of 0.6 and height of 0.6 m. The hydraulic performance of one-cycle triangular and trapezoidal labyrinth weirs with two, four and 6 guide vanes was compared. According to the results, the vanes with a placement angle of 60∘ in the trapezoidal weirs and a placement angle of 45∘ in the triangular weirs on the crests of weirs caused a further increase in the discharge coefficients of weirs. Consequently, at a constant hydraulic head (Hd/P) of 0.2, the discharge coefficient of a trapezoidal weir with two and six guide vanes increased by 38.8 and 10.3%, respectively, as compared to a trapezoidal weir without a guide vane. Furthermore, at a constant hydraulic head (Hd/P) of 0.2, the discharge coefficient of a triangular weir with two and six guide vanes increased 28.3% and 11.7%, respectively, as compared to a triangular weir without a guide vane.