Reference : Mitigation Techniques for Nappe Oscillations on Free-Overfall Structures
Scientific journals : Article
Engineering, computing & technology : Civil engineering
Mitigation Techniques for Nappe Oscillations on Free-Overfall Structures
Lodomez, Maurine mailto [Université de Liège - ULiège > Département ArGEnCo > HECE (Hydraulics in Environnemental and Civil Engineering) >]
Crookston, Brian mailto [Université de Liège - ULiège > Département ArGEnCo > Département ArGEnCo >]
Tullis, Blake mailto []
Erpicum, Sébastien mailto [Université de Liège - ULiège > > Scientifiques attachés au Doyen (Sc.appliquées) >]
In press
Civil Engineering ASCE
American Society of Civil Engineers
[en] Nappe oscillations ; Hydraulic models ; Nappe vibrations
[en] Nappe oscillation is a phenomenon that can have an undesirable impact to the local environmental (e.g., nearby residences, parks) as the phenomenon has been observed to produce a significant level of noise caused by acoustic pressure waves. As a result, a detailed investigation was undertaken to identify practical and effective mitigation solutions to address these effects for free-overfall structures. Nappe oscillations were studied using a prototype-scale linear weir (weir length of 3.5 m and fall height of 3 m), a high-speed camera, and audio equipment. The effectiveness of various crest modifications to reduce nappe oscillation and any corresponding impacts to hydraulic efficiency were evaluated. The test matrix included the optimization (position and spacing of elements) of three mitigation solutions: 12 configurations with projecting elements, 5 configurations with deflectors and one configuration with a step. These three countermeasures proved to be effective after the optimization of their characteristics. In particular, deflectors or a step produced the maximum noise reduction while decreasing the discharge coefficient by less than 3 % over the range of experimental conditions.

File(s) associated to this reference

Fulltext file(s):

Restricted access
Manuscript.pdfAuthor preprint10.78 MBRequest copy

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.