Stilling basin at Vatnsfell dam, Iceland - problem of water cascade and its solution
2005 (English)In: HYDRO 2005, The international journal on hydropower and dams , 2005Conference paper (Refereed)
A converging overflow spillway and a bottom outlet share a stilling basin at the Vatnsfell dam, Iceland. When commissioned in 2001, the stilling basin experienced problems of water cascade onto its right rock slope at the discharge interval 70 – 130 m3/s from the bottom outlet. Beyond this scope, the stilling basin functions satisfactorily as designed. Corresponding to the discharge interval, the opening of the radial gate of the outlet varies between 1.0 – 2.5 m, depending on the reservoir water level. The height of the baffle blocks immediately downstream the gate is 1.5 and 2.0 m. An improper relationship between the flow depth and the block height was considered to account for its occurrence. Hydraulic model studies were made to study the reason and to investigate potential countermeasures. The test results led to the suggestion of cutting two or alternatively four baffle blocks located immediately downstream the outlet. To completely remove any blocks or raise the end sill of the stilling basin was not advisable. According to the recommendation, two baffle blocks adjacent to the right sidewall were cut by a half meter in the prototype. Flow release from the outlet showed that the stilling basin functioned satisfactorily and without cascading up to the full discharge capacity. No other countermeasures were considered necessary.
Place, publisher, year, edition, pages
The international journal on hydropower and dams , 2005.
Vatnsfell, bottom outlet, water cascade, model tests
IdentifiersURN: urn:nbn:se:kth:diva-179793OAI: oai:DiVA.org:kth-179793DiVA: diva2:889458
HYDRO 2005, Oct 2005, Villach, Greece
QC 2016010142015-12-252015-12-252016-01-04Bibliographically approved