Aeration Performance of a Hydraulic Jump

Hydraulic jump is occurred at the transition from supercritical to subcritical flow which is characterized with energy dissipation due to highly turbulent flow, air entrainment, and macro-scale vortices. In this study self-aeration performance of a classical hydraulic jump beyond a sluice gate, has been investigated in a 0.5 m wide flume. Experiments were conducted for a range of upstream Froude numbers 2–6, and unit discharges 2 x 10^–2 – 5.3 x 10^–2 m³/sm. It was appeared that the aeration efficiency of a hydraulic jump was mostly dependent on head loss, and then to the unit discharge positively. Further, turbulence structure of the hydraulic jump, which ensures the entrainment of air into water, was highlighted by using an Acoustic Doppler velocimeter at low Froude numbers. An empirical formula predicting aeration efficiency for hydraulic jumps was developed by using non-linear regression analysis. Good agreement between measured and predicted aeration efficiency values was obtained.