抄録
Hydraulic jumps are characterized by air entrainment and strong turbulence with surface rollers. The characteristics of air entrainment in steady jumps were investigated experimentally. The air entrainment region in jumps is classified into an advective diffusion region and a breaking region. The air-concentration ratios in the advective diffusion region for a jump with a fully developed inflow condition (FD) are larger than those for a jump with a partially developed (PD) and an undeveloped inflow condition (UD) under a given inflow Froude number. Whereas, the air-concentration ratios in the breaking region is independent of the inflow conditions (UD, PD, and FD). For a given inflow condition, the air concentration ratios in both the advective diffusion region and the breaking region increase with the Froude number. Further, the distribution of air concentration ratio with velocity measurements and high-speed video camera images of the supercritical inflow reveals the air entrainment mechanism in both the advective diffusion and the breaking regions.
