Air entrainment of hydraulic jump aeration basin

In order to avoid the cavitation damage and the decrease of the energy dissipation of the stepped spillways with a large unit discharge, the air entrainments of the hydraulic jump aeration basin (HJAB) are theoretically and experimentally investigated for the hydraulic-jump-stepped spillway developed by the authors. It is shown that the submerged degree of the hydraulic jump and the air concentration in the measuring section are all functions of the dimensionless discharge, the length and the end sill height of the HJAB. The submerged degree sigma decreases with the increase of the dimensionless discharge or the dimensionless length of the HJAB, but increases with the increase of the dimensionless height of the end sill of the HJAB. The flow regimes near the critical hydraulic jump, namely, at sigma = 1.0, have the best effect of the air entrainment for the flow at the measuring section and then that of the stepped spillway.