Effects of intake-entrance profiles on free-surface vortices
2014 (English)In: Journal of Hydraulic Research, ISSN 0022-1686, E-ISSN 1814-2079, Vol. 52, no 4, 523-531 p.Article in journal (Refereed) Published
Intake free-surface vortices can cause efficiency losses, flow fluctuations and even structural damages. Experiments were performed to examine the effect of entrance shapes on the critical submergence. Seven entrance shapes were devised and tested, including a square-edged, a bell-mouthed, three symmetrical conical and two conical profiles with eccentricity. The focus of the study was on a range of Froude numbers from 0.25 to 0.65. The square-edged shape appeared to show the highest local head-loss compared to other shapes. Steady counter-clockwise vortices characterize all the intake profiles except in a narrow water tank. The experiments show both discrepancy and similarity between the intake profiles. The critical submergence of the bell-mouthed intake is lower when compared to the square-edged shape. For the other profiles, it is proportional to the Froude number. A closer sidewall may lead to larger critical submergence in the case of weak circulations. The results demonstrate that the intake-entrance profile has an important effect on the critical submergence.
Place, publisher, year, edition, pages
Taylor & Francis Group, 2014. Vol. 52, no 4, 523-531 p.
Critical submergence, downward intake, entrance profile, free-surface vortex, Froude number
IdentifiersURN: urn:nbn:se:kth:diva-141190DOI: 10.1080/00221686.2014.905504ISI: 000341847100009ScopusID: 2-s2.0-84912001646OAI: oai:DiVA.org:kth-141190DiVA: diva2:695546
QC 201601042014-02-112014-02-112016-01-04Bibliographically approved