Author(s): Shuai Li; Jianmin Zhang; Weilin Xu

Linked Author(s): Jianmin ZHANG, xu_wl

Keywords: Air concentration; air–water flows; flow resistance; stepped spillway; turbulent dissipation rate; velocity distribution; water head dissipation ratio

Abstract: This study numerically investigated eight configurations of stepped spillways with 45° slopes. The rounded and sharped configurations exhibited the highest and second highest air concentrations, respectively. The baffled-shifted rounded configuration had the lowest air concentration and the highest turbulent dissipation rate and water head dissipation rate. The largest interfacial velocities and the smallest frictional drag were observed for the rounded configuration. The turbulent dissipation rate of the rounded configuration was higher than that of the sharped configuration. The silled-shifted sharped configuration had the lowest turbulent dissipation rate. Intense turbulent dissipation rates occurred in the mixing layer and the interfacial region with air concentrations of 90%. The residual energy of the baffled-shifted rounded configuration was approximately 8% and 13% lower than that of the rounded and sharped configurations, respectively. The highest residual energy under the baffled-shifted sharped configuration appeared to be associated with the lowest turbulent dissipation rate.

DOI: https://doi.org/10.1080/00221686.2017.1286393

Year: 2018