Sedimentation at labyrinth weirs – an experimental study of the self-cleaning process. Issue 4 (4th July 2019)

• Record Type: Journal Article
• Authors: Gebhardt, Michael; Herbst, Jakob; Merkel, Jennifer; Belzner, Fabian
• Is Part Of: Journal of hydraulic research. Volume 57:Issue 4(2019)
• Page Start: 579
• Page End: 590
• Publication Date: 2019-07-04
• Subjects: Control structure -- hydraulic structure design & management -- laboratory study -- labyrinth weir -- sedimentation -- turbulence–sediment interaction; Hydraulics -- Research -- Periodicals; Hydraulic engineering -- Periodicals; Hydraulic engineering; Electronic journals; Periodicals; 621.2
• DOI: 10.1080/00221686.2018.1494053
• Languages: English
• ISSNs: 0022-1686

Abstract

ABSTRACT: Labyrinth weirs are passive flow control structures. It is assumed they hold back more sediment compared to movable weirs. Only a few model tests have been conducted for specific prototypes up to now. Therefore, systematic experimental tests were performed on a physical model with a rectangular and a trapezoidal labyrinth weir. Four sediments were tested under various flow conditions: fine sand, fine gravel, medium grained gravel and polystyrene granules. The results confirmed the self-cleaning ability of labyrinth weirs. Furthermore, the model tests show that the densimetric Froude number is the dominant parameter and has a significant effect on the scouring mechanism. It can be seen that self-cleaning begins at a rectangular labyrinth weir at lower discharges compared to a trapezoidal labyrinth weir. Finally, the self-cleaning process can be described and a threshold can be determined to predict scouring in dependence of geometry, discharge and sediment properties