Risk Analysis of Cavitation in Hydraulic Structures

Abstract

Damages as a result of cavitation are ever existing problems in high-head spillways. This article presents a brief introduction to the problems associated with high-head spillways and describes a procedure that takes into account the flow near the chute surface where the phenomenon occurs, instead of the mean flow. Application of risk analysis methodology presented can be used to estimate whether there is a possibility of cavitation or there is necessity to determine where the first aereator should be located. The advantage of the procedure herein presented takes into consideration an important new variable, such as the surface roughness. In addition, emphasis should be placed first on the need to investigate other high-head dams which climate change may have exposed them to this kind of damages. Second, there is a need to make measurement in prototype. Finally, to underscore the importance of these problems, a comment is made concerning the Oroville Dam contingency in the state of California, (United States).