Unsteady numerical analysis of waver of secondary flow on channel flows with triangular roughness on side walls

Abstract

Turbulent flow structures in open channels with various roughnesses are important topics in hydropower engineering. In this study, applicability of numerical mode with URANS type turbulence models and LES for simulating the channel flows with triangular roughness on side walls..We carried out the experiments and showed the comparisons with experimental data and calculated results were generally adequate. The numerical result showed that non-linear k-ε models and LES could reproduce the velocity profile, formation of cross - sectional secondary currents in the channel and the maximum-velocity-dip phenomena. Furthermore, we visualized vortex pipe from the calculated result and investigated the three-dimensional unsteady flow structures around side walls such as waver of secondary flow.