Start Date
4-30-2025 1:30 PM
Description
Stepped spillways offer energy dissipation advantages and construction efficiencies over smooth spillway chutes. Energy dissipation is typically estimated using empirical relations that depend on chute slope, unit discharge and relative step height. Open-channel tests of model spillways experience self-aerated air-water flow downstream from the aeration inception point, and the presence of air dramatically affects energy dissipation and flow depth, making it difficult to separately determine the effects of step geometry and other basic flow properties. The 1992 doctoral dissertation of Marcos José Tozzi from the Polytechnic School of the University of São Paulo included open channel stepped spillway tests with water as well as closed conduit tests using air as the working fluid. A new review of the air-tunnel tests was recently made to seek a better understanding of geometric influences on stepped chute flow resistance. The work contributes useful background information for new closed conduit water tunnel tests of stepped chute flow resistance.
Included in
Ahead of His Time? A Reanalysis of the Air-Tunnel Stepped Chute Studies of Marcos José Tozzi
Stepped spillways offer energy dissipation advantages and construction efficiencies over smooth spillway chutes. Energy dissipation is typically estimated using empirical relations that depend on chute slope, unit discharge and relative step height. Open-channel tests of model spillways experience self-aerated air-water flow downstream from the aeration inception point, and the presence of air dramatically affects energy dissipation and flow depth, making it difficult to separately determine the effects of step geometry and other basic flow properties. The 1992 doctoral dissertation of Marcos José Tozzi from the Polytechnic School of the University of São Paulo included open channel stepped spillway tests with water as well as closed conduit tests using air as the working fluid. A new review of the air-tunnel tests was recently made to seek a better understanding of geometric influences on stepped chute flow resistance. The work contributes useful background information for new closed conduit water tunnel tests of stepped chute flow resistance.