2008 Volume 52 Pages 787-792
Stepped channels are effective for dissipating the energy of supercritical flow that occurs at steep channels. Generally, the flow conditions in stepped channels have been classified into skimming flow, transition flow, and nappe flow. Also, stepped channel flows have been characterized as aerated flows. For design purposes, it is important to predict the aerated flow velocity, the air-concentration, and the energy head of aerated flows in skimming, transition, and nappe flows.
In this paper, aerated flow characteristics of skimming, transition, and nappe flows have been investigated for a wide range of relative step height S/dc under a given channel slope θ=19°. It was found that the velocity and air-concentration profiles characterize each flow condition. The energy head of aerated flows E in skimming, transition, and nappe flows has been determined from the air-concentration C and the aerated flow velocity u.
