Department of Civil & Environmental Engineering, Shiraz University 4 Namazi Sq. Zand Ave., Shiraz, Iran
Labyrinth spillway has become an appropriate choice to increase an existing spillway’s capacity. Thus, it is necessary to understand the hydraulic performance of labyrinth spillways/weirs. This paper numerically solves turbulent flow over labyrinth spillways/weirs and determines the discharge coefficients. Reynolds governing equations, turbulence k-ε model, and the volume of fluid (VOF) model are numerically solved to define pressure, velocity, and the free surface flow profiles. The numerical results are comparable to those obtained from physical modeling with maximum 6.43% error relative to results of physical modeling. Present study indicates that numerical simulation can be used to supplement physical modeling. Thus, by using numerical solutions the site specifics of the spillway which are often different from the conditions of design curves can be investigated. Also, the effect of different shapes of apex on discharge capacity of the labyrinth spillway is investigated in this study. The analyses show that labyrinth spillways with round apex shape are the most efficient spillways. Numerical determination of free water surface is presented and discussed, which is helpful for optimum design of stilling basin and leading walls.