Numerical simulation of ow over labyrinth spillways

Spillways play an important role in the safety of dams. to ensure the safetyof dams, spillways should be designed considering oods with long return periods. toincrease the discharge capacity of a spillway, a designer can increase the crest length usingthe labyrinth spillway. for high head conditions, the local submergence may decreasethe eciency of a labyrinth spillway. in this study, the hydraulic characteristics of linearand arced labyrinth spillways are compared, and the eect of the downstream bed levelon the discharge coecient of labyrinth spillways is studied numerically. the numericalsimulations are done using flow-3d software. rng k ?? model is used for turbulencesimulations and the free-surface proles are calculated by vof method. experimental dataof pervious researchers are used for validation of the proposed numerical model. the resultsshow that in the high head conditions, lowering the downstream bed level of a labyrinthspillway increases its eciency, especially in the case of an arced labyrinth spillway