Study on stabilization of small overflow induced free surface

Stable water supply to turbine system is essential requirement for small hydro power system using waste cooling water. Complex flow pattern in water channel is expected to be stable with overflow discharge. For reliable hydro power system, detailed analysis for flow characteristics is required to identify proper design parameters. In this study, small overflow over sluice is proposed to have stable free surface flow which eventually makes entire flow stable. Three-dimensional numerical analysis with this overflow is performed with standard k-e model and Volume of fluid (VOF) model. Three different design parameters of height of sluice, shape of crest and height of inflow hole are selected and evaluated for their effects through analysis. The overflow with low height of sluice stabilizes free surface flow and triangular crest shape enhances flow stabilization. Water supply through the inflow hole to the turbine system is stable with low height one.