Analysis of hydraulic parameters in determining the occurrence of cavitation in the spillways of the Furnas, Luiz Carlos Barreto de Carvalho and Batalha hydroelectric power plants

Análise dos parâmetros hidráulicos na determinação da ocorrência de cavitação nos vertedouros das usinas hidrelétricas Furnas, Luiz Carlos Barreto de Carvalho e Batalha

ABSTRACT

The hydrodynamic conditions to which hydraulic structures such as spillways and stilling basins of dams are submitted under given conditions favor the occurrence of cavitation, damaging the concrete surfaces. This damage may be intensified by the cumulative effect of the successive hydrologic events that characterize the operational regime of these structures. Thus, the purpose of the present article is to identify the propensity for damage caused by cavitation by using SpillwayPro software to estimate the hydraulic parameters of flow (mean velocities and cavitation indices) based on information on smooth chute spillways at the Furnas, Luiz Carlos Barreto de Carvalho and Batalha hydroelectric power plants. The results shown were compared to the critical limits of cavitation defined in the literature on photographic records of inspections performed in the field. The highest mean velocities estimated coincided with the zones where the worst potential damage of the structures was identified. Nevertheless, most of the cavitation indices obtained did not present results similar to the limits presented by different authors, and thus do not favor the indication of cavitation risks due to this parameter in the spillways examined.

Keywords:
Cavitation index; Hydraulic surfaces of concrete; Operation of hydraulic structures; SpillwayPro