Labyrinth Spillways
|
| Labyrinth Weir, London.
(Image Source: Wikimedia) |
“The flow capacity of a weir is largely governed by the weir length and crest shape. A labyrinth weir is a linear weir folded in plan-view; these structures offer several advantages when compared to linear weir structures. Labyrinth weirs provide an increase in crest length for a given channel width, thereby increasing flow capacity for a given upstream head. As a result of the increased flow capacity, these weirs require less free board in the upstream reservoir than linear weirs, which facilitates flood routing and increases reservoir storage capacity under base flow conditions (weir height may be increased). In addition to spillways, labyrinth weirs are also effective drop structures, energy dissipaters, and flow aeration control structures."[1] Labyrinth weirs are ideal for controlling water levels in rivers, channels, and reservoirs. They can also handle higher flow rates with a smaller footprint compared to conventional weirs, making them advantageous in space-constrained environments.
The design of a labyrinth weir should include consideration of geometric configuration, hydraulic efficiency, and structural integrity. The dimensions and angles of a labyrinth weir's walls are essential in determining the flow capacity and head-discharge relationship. In general, as the head on a labyrinth weir increases, the overall efficiency of the weir decreases. This is due to localized submergence within the individual cycles of the weir. Comprehensive laboratory testing[1] has been performed to estimate discharge capacity for a large range of potential weir geometries and head conditions, including submerged conditions due to downstream hydraulic constrictions. Computational fluid dynamics (CFD) simulations and physical modeling can also be helpful in optimizing geometric parameters to achieve desired performance.
Other Resources
Labyrinth Weirs, Dissertation by Brian Crookston, Utah State University
Citations:
Revision ID: 7698
Revision Date: 09/28/2023