Author(s): Jaafar S. Maatooq; Zainab Ali Zghaier

Linked Author(s):

Keywords: Expansive transition; Abrupt outlet; Subcritical flow; Velocity distribution; Head loss; Sudden transition

Abstract: Eddies that result from the flow separation in abrupt expansion transition structures lead to serious problems in the bed and sides of the downstream channel. The head loss produced through expansion, on the other hand, is important as it affects thedownstreamstage. Thisstudyhasbeenconductedforsubcriticalflowtodevelopthehydraulicperformanceofanabrupt outlettransition. Theaimofthisstudyistokeeptheheadlossesatlowerstagesandachieveauniformvelocitydistribution across the width at the end of transitiondownstream (in the transverse direction) by spreading the flow laterally. A new baffle column model that has not been previously investigated was adopted and installed at a specific location to be a dispenser inside the transition. This model is semi-circular in shape convex against the flow, by which the flow spreads and distributes across the width with highly regularity and uniformity. At the same time, this shape keeps the head losses at a minimum stage. The results of this attempt proved that it has considerable advantages both hydraulically and economically over using a flared wall transition. Theresults haveindicated thattheuniformityinlocalvelocity distributionacrossthewidthhasincreased, ashorterlengthof transition has been achieved, and no more head loss than that occurs at plain abrupt transition.

DOI: https://doi.org/10.15142/T32M05

Year: 2018