E .Fadaei kermani - MSC Student of Hydraulic Structure, Dept. of Civil Eng, Univ. of Shahid Bahonar
G .A. Barani - Professor, Dept. of Civil Eng, Univ. of Shahid Bahonar, Kerman

Cavitation phenomenon is a common and very complex process on spillways that threatens the stability of spillway structure. This phenomenon occurs when pressure in lower nappe of flow falls below thecorresponding vapor pressure. Cavitation phenomenon in hydraulic structures can be a function of flowvelocity, flow pressure, duration of operation, boundary roughness and alignment, strength of materials from which the boundary is constructed and the amount of dissolved air in water. Occurrence ofcavitation damage to a spillway can be predicted using cavitation index. In this method to reduce cavitation danger in spillways, the flow cavitation index along the spillway should be more than cavitation inception index; therefore in this study the role of flow cavitation index in prediction of cavitation damage on spillways has been investigated

Cavitation, Spillway, Cavitation index, Cavitation inception index