Experimental study of discharge coefficient of trapezoidal arced labyrinth weirs of widened middle cycle

Abstract

Arced labyrinth weir is a certain type of nonlinear weirs with a very high discharge capacity. Thanks to the increased effective length and the ensuing increased discharge capacity of these weirs, they can be used in dam spillways and water regulating structures. This study focused on trapezoidal Arced labyrinth weirs (TALW) of widened middle cycle. Various experiments were performed to evaluate the effect on discharge coefficient of various geometric parameters, including the ratio of inside apex width of the end cycles to that of the middle cycle (w2/w1) and the ratio of the length of labyrinth weir (Apron) in flow direction to the width of the middle cycle (B/w1). Results of this study showed that with a decrease in w2/w1 from 0.42 to 0.30, discharge coefficient (Cd) would increase by 13–33%.