Experimental study of cavitation index in an ogee spillway by considering convergence angle of sidewalls

Abstract Cavitation is among the most complex and common damage occurring in spillway structures, which one of expensive parts a dam. The cavitation index, as efficient approaches, can be used to analyze this important hydraulic phenomenon. present study examines changes index caused by convergence angle an ogee spillway's sidewalls with arc plan. To end, was constructed on 1:50 scale. Then, it tested four different angles, including 0°, 60°, 90°, 120°, relative six flow rates per unit width ranging from 6.74 48.42 (l/s)/m. results indicated that rate increased, relatively declined at both crest chute while growing its toe. It observed lowest found 1.54 in.X/Hd = 2.42 0° 40.52 (L/s)/m.