Author(s): B. M. Crookston; A. Anderson; L. Shearin-Feimster; B. P. Tullis

Linked Author(s): Blake P. Tullis

Keywords: Spillway; Labyrinth; Nappe; Vibration; Acoustics; Physical modelling

Abstract: Linville Land Harbor Dam was recently rehabilitated and provided with a labyrinth spillway to increase flood passage capacity. Nappe vibration, a condition that can occur at hydraulic structures with a free overfall, has been observed for low flows. The associated noise affects a private residence in close proximity to the spillway. As a result, a detailed investigation has been undertaken at the Utah Water Research Laboratory that uses physical modelling (linear weirs) to study mitigation options. Nappe vibration for a fully vented nappe has been observed in the laboratory. Preliminary results indicate that nappe breakers are a less desirable mitigation option due to spacing requirements. Adding roughness to the crest is highly effective as it increases turbulence, perturbs the laminar boundary layer, decreases nappe uniformity, and alters the flow characteristics where the nappe impacts the tailwater.

DOI: https://doi.org/10.14264/uql.2014.30

Year: 2014