EXPERIMENTAL STUDY OF FREE-SURFACE AERATION AND TURBULENT PROCESSES DOWN AN EMBANKMENT DAM STEPPED SPILLWAY

摘要

Research on stepped chute hydraulics has become an important tool for operational safety and design optimisation of these structures. Detailed experimental data is scarce and limited to very steep slopes (α > 50°). This work details an experimental investigation of the physical flow characteristics of stepped chute flows conducted in a large-size laboratory model with a moderate slope typical of embankment dam slopes (h = 0.1m, α = 16°) operating with transition and skimming flow regimes. New original data include air concentration, air-water flow velocity and air-water flow turbulence intensity. The results suggest that air-water flow characteristics are not totally understood although there are some well-known features (eg. cavity recirculation) that influence significantly its behaviour in both skimming and transition flow conditions.