HYDRAULIC PERFORMANCE OF LABYRINTH WEIRS FOR HIGH HEADWATER RATIOS

Physical and numerical modelling were used to investigate the hydraulic performance of labyrinth weirs operating under high headwater ratios (greater than 1). Physical modelling was conducted in a rectangular flume in a laboratory setting. Numerical modelling was conducted with commercially available computational flow dynamic (CFD) software (Flow-3D). Preliminary results indicate that the CFD model can accurately predict the labyrinth weir head-discharge relationship obtained from the physical model, including upstream heads (relative to the crest) that exceed the weir height. Furthermore, the information presented in this paper indicates that the hydraulic design curves developed by Crookston in 2010 may be acceptable for headwater ratios up to 2.0 or more.