Influence of the Number of Trapezoidal Labyrinth Weir Cycles on the Hydraulic Characteristics of the Weir

Abstract

The labyrinth weir that is viewed from above has a zig-zag shape. The main objective is to extend the spillway so that the water level upstream of the weir is as low as possible or to increase the discharge capacity. The shapes of labyrinth weirs based upon cycle shape are triangular, trapezoidal, and rectangular. However, besides the shape of the spillway, several parameters affect its hydraulic characteristics. Therefore, this paper intends to explore the effect of the number of cycles on the trapezoidal labyrinth weir on the hydraulic characteristics of the weir, based on an experimental study. There are two types of model tests one-cycle and two-cycle. Both of the models have a 2300 mm length of the spillway and were made of fiber cement board with a thickness of 20 mm and tested in a rectangular flume of 950 mm width, under various discharges to fulfill the goals of this study. The results of this study show that the discharge capacity through a one-cycle model (0.0064m3/s to 0.0150 m3/s) has a larger capacity than that of a two-cycle model (0.0023m3/s to 0.0095 m3/s). Analyzing can determine that the most efficient hydraulically are the less cycle number of labyrinth weir.