A labyrinth spillway is an overflow weir folded in plan view to provide a longer total effective length for a given overall spillway width. A labyrinth spillway has advantages compared to the straight overflow weir and the standard ogee crest. The present paper proposes a mathematical model for a double and triple cycle labyrinth weir based on experimental results. A concrete flume was constructed in the laboratory and a double and triple cycle labyrinth weir with 25° labyrinth angle was installed. The design of labyrinth weir installed in the concrete flume was carried out as per Tullis's guidelines. A mathematical model for coefficient of discharge for labyrinth weir has been proposed using the experimental data.

A spillway consists of a type of control structure which is normally placed perpendicular to the flow direction. The capacity of spillway or a weir refers to the discharge for a given head of flow over its crest. If the capacity of weir is to be increased for a given width of approach, the labyrinth spillway or weir offers a feasible alternative. Labyrinths are weirs folded in plan view. Labyrinths can also serve as drop structures on canal systems. If used on a canal system, a set of labyrinth weirs will serve as energy dissipators and, at the same time, maintain more constant flow depth in the canal than achieved with a conventional drop structure. A labyrinth spillway is an overflow weir folded in plan view to provide a longer total effective length for a given overall spillway width. A labyrinth spillway has advantages compared to the straight overflow weir and the standard ogee crest. The total length of the labyrinth weir is typically three to five times the spillway width. Its capacity varies with head and is typically about twice than that of a standard weir or overflow crest of the same width. Labyrinth weirs can be used to increase the outlet capacity for a given spillway crest elevation and length or to increase storage by raising the crest while maintaining the spillway capacity. The variables that need to be considered in designing a labyrinth weir include the length and width of the labyrinth, the crest height, the labyrinth angle, the number of cycles, and several other less important variables such as wall thickness, crest shape and apex configuration.

Soil And Water Sciences Journal, Labyrinth Weir, Double Cycle, Triple Cycle, Coefficient of Discharge, Mathematical Model, Canal Systems, Weir Structures, Crest Elevation, Mathematical Model, Experimental Data, Weir Geometry.