The experimental analysis of hydraulic characteristics of labyrinth weirs

ABSTRACTMaster ThesisTHE EXPERIMENTAL ANALYSIS OF HYDRAULIC CHARACTERICTICS OFLABYRINTH WEİRSÖmer BİLHANFırat UniversityGraduate School of Natural and Applied SciencesDepartment of Civil Engineering2005, Page: 68The labyrinth spillways are an effective method which is applied for increasing thespillway discharge capacity in dams. The capacity of a labyrinth spillway is a function of thetotal head, the effective crest length and crest coefficient. The crest coefficient depends on thetotal head, weir height, crest shape and the angle of the side legs. The design procedure allowsthe angle of the side walls and the number of cycles to be varied until the desired layout andcapacity are achieved.In this study, the discharge that the labyrinth spillways pass in certain total head aremeasured by giving them triangular, trapezoidal, rectangular and circular shapes in the plan, thedischarge coefficient are determined and compared with data acquired from linear weirs.Furthermore, the side wall angles of trapezoidal and triangular labyrinth weirs that are tested arefixed as 26.83°, 33.53° and 45.57°.In the first section; the purpose of this study with its contents was explained and itsadvantages and importance were accented.In the second section; hydraulic characteristics of labyrinth spillway flows werepresented.In the third section; application area of the labyrinth weirs were presented.In the fourth section; the articles, related to this study, were analyzed and presented.In the fifth section; the experimental setup and the materials which were used inexperiments were given with figures.In the sixth section; the experimental results obtained from the study were evaluated.In the seventh section; the conclusions were presented. It was found that dischargecapacity of labyrinth weirs is closely related to weir geometry, weir shapes and flow conditions.Keywords: Spillway, Labyrinth weir, Linear weir, Discharge coefficient, Water head,Weir height, Auxiliary spillway, Crest length.IX