Characteristics of air entrainment in hydraulic jumps.

Masayuki Takahashi, Iwao Ohtsu

Thursday 2 july 2015

16:15 - 16:30h at South America (level 0)

Themes: (T) Water engineering, (ST) River and coastal engineering

Parallel session: 13C. Engineering - Industrial

The hydraulic jumps is characterized by air entrainment and strong turbulence with the surface rollers. The characteristics of air entrainment in jumps were investigated experimentally. The air entrainment region is classified into the advective diffusion region and the breaking region. The air concentration in the advective diffusion region for a jump with a fully developed inflow condition is larger than that for an undeveloped inflow condition for a given inflow Froude number, whereas the air concentration ratio in the breaking region is independent of the inflow condition. For a given inflow condition, the air concentration in both the advective diffusion and breaking regions increase with an increasing inflow Froude number. The air entrainment mechanism in jumps is explained for both the advective diffusion and breaking regions.