Author(s): Yongfei Qi, Jianmin ZHANG

Linked Author(s): Jianmin Zhang

Keywords: Stepped dropshaft; Standing wave; Numerical simulation; VOF method;

Abstract: Motivated by stepped spillways which are known for high aeration performance, a novel kind of vortex
dropshaft, stepped dropshaft, is proposed to increase the energy dissipation and reduce the risks of cavitation damage. Because of the deflection by sidewalls and the blocking by horizontal steps, standing waves are commonly generated on each step in the dropshaft. Therefore, to discuss the properties of the standing waves (the relative height, the location and the extent), the VOF method in conjunction with SST k-w turbulence model is used to simulate the hydraulic properties of the standing waves in the dropshaft with different step geometries under different discharges. The calculated results reveal that, with the increase of flow rate, the height of the standing waves increases and the location of the maximum elevation of the standing waves moves downstream, while the extent increases incipiently and decreases subsequently. The geometric properties show no obvious influence on the characteristics of the standing waves.

DOI: https://doi.org/10.3850/38WC092019-1100

Year: 2019