Weir jet flow: Historical advance from weir to standard spillway

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Willi H. Hager, Robert M. Boes

Monday 29 june 2015

16:45 - 17:00h at Africa (level 0)

Themes: (T) Water engineering, (ST) Experimental facilities and instrumentation

Parallel session: 3F. Engineering instrumentation

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Weir flow over the sharp-crested, vertical and fully-aerated weir is historically considered for free flow conditions. The motivation of this research is in the definition of the standard spillway crest geometry, which under the design head is identical to the lower nappe profile of the former weir type. The adoption of this procedure ensures that pressures on the crest zone are exactly atmospheric at design discharge, so that no problems arise with flow separation and cavitation damage. Starting from Henry Bazin the advance of this procedure is highlighted by researches conducted by Ettore Scimemi in the 1930s, by the US Bureau of Reclamation in the 1940s, by Hunter Rouse in the 1950s, leading to the developments proposed by Eric Markland, and Theodor Strelkoff in the 1960s. Finally, the careful data of the group around the Italian Augusto Ghetti are highlighted. This research therefore addresses both the practitioner and the hydraulic researcher, given the relevance of the standard spillway in hydraulic engineering.